Standup Zone Forum
The Foil Zone => Foil SUP => Topic started by: sharksupper on April 14, 2018, 12:48:12 PM
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Since my Foilmount failed, I'm going to remove that and do it the right way this time. Does anyone make a foil track cassette yet? I don't want tuttle, so not going there. If no one makes a track cassette, how does one go about doing it themselves? Does it need to go all the way to the top of the board like a tuttle install? Info much appreciated!
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How does this box look? http://www.rideengine.com/GEAR/surf-foil/Surf-Foil-Track-Box.html
Think it's up for SUP surf duty?
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Or there is this one: http://www.greypaddleboards.com/product/50mm-high-density-hydrofoil-mount-insert/
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I've got to ask why you don't want a Tuttle. If I was going to do the work of installing tracks in a board I'd do a combination track/Tuttle.
You don't need to connect the tracks to the top and bottom, they work without that, but I think over time the cassette will work against the EPS and crush it. I made a cassette out of XPS 100 foam--the 100PSI blue construction foam--cut a square hole in the bottom of the board and dug the EPS out of the board to expose the fiberglass of the deck. I smeared the underside of the deck and the edges of the hole with epoxy and then pressed the cassette into the hole with a sheet of 6oz prewet glass under it. I let the whole mess set up and then cut it flush to the bottom using my high-tech crosscut saw. Then I sanded it flat and routed the slots for the mast tracks. I also set these into the xps with glass under them, but this time I slit the edges of the wetted glass and spread it flat onto the XPS, laid on a sheet of poly and put a slab of marble two inches thick on top to weight it. My shop used to be a marble cutting outfit. I have TONS of scrap marble. If I were doing this today I'd sink a deep Tuttle between the two tracks right then. As it was I did that later. I sanded again, then bagged on two layers of carbon and one of 4oz. Sanded and hotcoated.
Then a month later I decided it needed a Tuttle. Rod Parmenter left a GoFoil tuttle block at my shop which is a deep tuttle wrapped with PVC foam with carbon top and bottom, so I appropriated it. I cut a square the length of the block and then trimmed along the inside edges of the mast bases--the spread of the mast bases is narrower than the GoFoil box. I cut all the way through since the GoFoil tuttle is also deeper than the L41. I trimmed the tuttle block to fit the hole, glued it in place with Gorilla Glue, and the glassed it over top and bottom with carbon and glass. It would have been much easier to install a Chinook Deep Tuttle box the first time, but I thought I didn't want one.
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I suppose fin boxes are OK. I used Chinook mast tracks. Those cassettes look fine but they are obviously made to attach only to the bottom skin. They'd probably be fine. Since I don't know that they will be, I prefer to go for as strong as I can make them.
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How does this box look? http://www.rideengine.com/GEAR/surf-foil/Surf-Foil-Track-Box.html
Think it's up for SUP surf duty?
Yep, this is how you do it. Ride Engine showed it off at surf expo. I thought to just let everyone know the right way. Didn’t know they were having it made in China and selling it. It’s handy if you don’t have access to 2” thick divinycell.
I don’t trust anyone but chinook for my tracks.
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I don't want just tuttle because I got used to a longer mast and want to stick with at least 28"... with my 4" tall tuttle to track adapter I get my 28". However, I do have the WateRat tuttle box still from my other project, so I could do both, good idea! I also have some 1/4" or so divinycell sheet that I could stack up to get a taller cassette if needed. Right, ordering the RideEngine box!! Thanks guys!
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I found instructions on the Mac Kite site for the RideEngine box, do these sound legit? ok to follow?
http://www.mackiteboarding.com/2018-ride-engine-foil-track-box/
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The instructions are fine except they assume a 2.35" deep cassette is going to protrude past your deck when it's flush with the bottom.
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Yea, gotcha, so that's where I'll glue on my layers of divinycell on top of the cassette to make it to the top of the board.
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Since my Foilmount failed, I'm going to remove that and do it the right way this time. Does anyone make a foil track cassette yet? I don't want tuttle, so not going there. If no one makes a track cassette, how does one go about doing it themselves? Does it need to go all the way to the top of the board like a tuttle install? Info much appreciated!
Hi Sharksupper
I have always used 3mm ply wood, just use a circular saw to the depth that you want,
I generally go 3 inches deep then sink the wood in with epoxy,
then rout out for the fin boxes and resin them into the wood.
Then glass over the top.
I have always used this technique, for my kite surfing board, having run aground at 40kph still no sign of move ment.
I use this technique on my sup too.
I wouldn't bother with devinercell is still just a foam.....not a timber.
Have a look at the pic.
Cheers
Scuba
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That's pretty cool Scuba, though the plywood is just anchored to EPS. Still, that looks like a very strong and much cheaper way to go, PVC foam is damned expensive. I'll try that. Should work with Tuttles as well
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Yea, gotcha, so that's where I'll glue on my layers of divinycell on top of the cassette to make it to the top of the board.
I have become 100% comfortable with Gorilla glue. Its stronger than the divinycell, and the white beer cooler foam, sticks to everything, is waterproof and fills voids. Just be sure to mix a little water in to get it to set, and prevent internal bubbles.
Density Test:
https://www.youtube.com/watch?v=UgZ3A3igBbY
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Gorilla Glue vs. Divinycell Strength test:
https://www.youtube.com/watch?v=LM-txMeTjPo&t=2s
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Yes, the Ride Engine cassettes are money. Easy to install and very strong. Go for it.
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That's pretty cool Scuba, though the plywood is just anchored to EPS. Still, that looks like a very strong and much cheaper way to go, PVC foam is damned expensive. I'll try that. Should work with Tuttles as well
Hi pono bill
Yep it works the same with a turtle box the only difference is that I use a block at the front and back of the turtle, balsa at about 19mm thick straight down to the deck and resigned in between the ply, very strong.
I have made about 12 boards the only time I have had a failure is at the beginning when I just relied on the carbon to hold the boxes with no timber.
Hope this helps.
Scuba
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It does, I like your method. I'd say you're underestimating PVC foam though. Yes, it's still foam, but it's extremely strong--at least as strong as Balsa wood, and probably stronger than generally available balsa. Compressive and tensile strength of divynicell is over 100 psi. I think balsa wood ranges from 30 psi for soft to 150 psi for hard. The biggest benefit of using it is that whatever you set into it is not going to shift around in the PVC, and the much greater surface area lets you tie the structure to a lot of glass and carbon. If you tie it top and bottom it will be the last thing left when the board is a crushed up wad. Plus it's as easy to work as EPS--cuts and sands nicely.
That said, I'm looking forward to trying your approach.
Beasho--Gorilla glue is basically polyurethane foam. Yup it's strong, but it's hard to work--tears rather than sands, cuts or planes--and the density is variable. And that's one skanky piece of Divynicell you've got there. Are you suggesting pouring a big square of gorilla glue to set the mast tracks into? How would you do that? If you're saying set the mast tracks into the EPS with gorilla glue and call it good, then you're just relying on a little bit of bottom skin and the surrounding EPS to hold the tracks. I guess I don't know what you mean.
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Beasho--Gorilla glue is basically polyurethane foam. Yup it's strong, but it's hard to work--tears rather than sands, cuts or planes--and the density is variable. And that's one skanky piece of Divynicell you've got there. Are you suggesting pouring a big square of gorilla glue to set the mast tracks into? How would you do that? If you're saying set the mast tracks into the EPS with gorilla glue and call it good, then you're just relying on a little bit of bottom skin and the surrounding EPS to hold the tracks. I guess I don't know what you mean.
Gorilla glue has proven itself superior for:
1) Gluing together 2 halves of a broken board. I learned this from Stretch and have seen it successfully employed now many times (aka my SUP that broke in half 3 month old and then was put together and lasted 7 more years among others). Epoxy on this joint is heavier, runs and does NOT fill voids like the Gorilla glue.
2) Any small divot in the Styrofoam. Just lubed it up with Gorilla glue and cut off the excess with a knife. It is like a cheap fairing. Yes difficult to work with but you can do wonders with a sharp knife
3) Delamination of a board. Just drill holes 1" deep ~ 1/2" apart all through the delamination. Fill the holes with Gorilla glue. Cover with plastic wrap and then add 2 layers of glass above. Poor Mans Re-Lamination.
4) Gluing back together my Foil Box that failed in the middle of the divinycell cassette. I thought this was a sketchy repair and was waiting for it to fail again. 500+ waves later on progressively larger foils going from the KAI to the IWA to the Mailko 200 and it outlasted the board, which broke in half on its own.
https://www.standupzone.com/forum/index.php/topic,32837.msg370284.html#msg370284
With this repair I did use the Gorilla glue to fill large voids and then faired it off with a knife.
Essentially any where you would be comfortable with the 'beer cooler' foam as the matrix Gorilla glue should suffice and can be far superior. It is heavier, and you have to be careful to get even density but it will work with odd shaped cavities. Alternately use the Gorilla glue to set a larger piece of EPS, Divinycell or other foam without worrying about it being a perfect fit because the Gorilla glue will make it fit.
I have done several Fin box installations using the ProBox method. It involves filling the cavity with about 2 oz. of Epoxy. I never tried the Gorilla glue for that installation. I would still laminate with Epoxy but as an internal structural matrix the sky is the limit. You do have to worry about buoying the object up from the expansion.
Work with me, see what you can figure out. 8)
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Hi pono bill
Yep it works the same with a turtle box the only difference is that I use a block at the front and back of the turtle, balsa at about 19mm thick straight down to the deck and resigned in between the ply, very strong.
I have made about 12 boards the only time I have had a failure is at the beginning when I just relied on the carbon to hold the boxes with no timber.
Hope this helps.
Scuba
[/quote]
Could you post up a photo of this. I think I understand what you are describing.
Thanks, Tare
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Hi pono bill
Yep it works the same with a turtle box the only difference is that I use a block at the front and back of the turtle, balsa at about 19mm thick straight down to the deck and resigned in between the ply, very strong.
I have made about 12 boards the only time I have had a failure is at the beginning when I just relied on the carbon to hold the boxes with no timber.
Hope this helps.
Scuba
Could you post up a photo of this. I think I understand what you are describing.
Thanks, Tare
[/quote]
Yep I will post a pick here.
The blocks can be pine or what ever you have lying around they will be epoxyed to the deck, plywood, foam & hull.
This pic is just a mock up and no sizes are correct.
I prefer to use fin boxes for it gives me a little adjustment and I can get the correct angle of attack with a carbon wedge.
Cheers
Scuba 😉
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Thank you for the picture and for sharing your installation method. I am going to do this on my next foil board.
Still undecided on whether to go fin boxes or tuttle. The tuttle I've been running for a year has been bullet proof.
I can adjust the AOI (Angle of Incidence, thank you Lane, Ke Nalu) with shims between the fuselage and the mast. I can also move the entire fuselage forward (4") or backwards (10") from a starting point of (14") measured from the leading edge of the front wing to the back edge of the mast.
With tracks I would get some some additional mast height (2 1/2 to 3") due to the tuttle being mounted on the surface and not in the board.
Have you done any with tracks and a tuttle? if so any feedback?
Thank you, Tare
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Hey Newps, how are you getting so much position adjustability? Most fin and mast boxes are 10" long. Fin plates generally have the fixing holes on 8" centers along the edge. That gives 1" either way from centered in the box.
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Shoot! Based on this video it looks like my RideEngine box is not up to the job (Slingshot = RideEngine), funny they install a FoilMount over it. https://www.youtube.com/watch?v=98Nss6ibrrs
What's it going to take to put in Chinook boxes?
Do I order two 10" Chinook mast track boxes? Where's a good place to source large Divinycell?
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'Supper-
Where are you located? Have you ever installed a regular fin box before?
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Bay Area. I helped a friend replace a blown power box with a tuttle box on one of my boards a long time ago, but that's it. I think I'm up for the job, just need to know what to use. I want max strength after my recent experience (losing my foil). If the RideEngine box looks as thin as the FoilMount I'm not going to use it, I guess I'd have to make my own cassette from Chinook boxes then.
Right now trying to find a 1/2" router bit long enough to make it through the board (about 4" deep).
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Hey Newps, how are you getting so much position adjustability? Most fin and mast boxes are 10" long. Fin plates generally have the fixing holes on 8" centers along the edge. That gives 1" either way from centered in the box.
Dave CNC me a fuselage with an elongated mast attachment hole.
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Many mast plates have 8 holes, giving more adjustment range.
To my knowledge, Chinook is the only finbox using heavy glass fill during injection molding. It’s a son of bitch to sand because of this. Super strong. Other boxes are a joke. They sand like the plastic junk they are. Worthless for foiling.
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Many mast plates have 8 holes, giving more adjustment range.
To my knowledge, Chinook is the only finbox using heavy glass fill during injection molding. It’s a son of bitch to sand because of this. Super strong. Other boxes are a joke. They sand like the plastic junk they are. Worthless for foiling.
If the RideEngine box I get looks weak I'm going to go with the Chinook boxes. Do I go for the 10" boxes?
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Just confirmed with RideEngine, they do not use Chinook boxes in their cassette.
Chinook is out of 10" fin boxes (hole in the center of the track for bolt entry) for a month, but they do have 10" mast tracks (hole at end of track for bolt entry) so I ordered two two of those. After seeing a video of a destroyed RideEngine box, I don't think it will handle my abuse. Now just to find some big Divinycell...
update...
I just found out Fiberglasssupply had a pile of the 10" Chinook fin boxes, so I got a couple from them and canceled on the mast boxes from Chinook.
AircrafSpruce had 10"x12"x1" H100 Divinycell, so got 4 of those coming. (Board is 3-3/4" thick)
Found a 5-1/2" (total length) router bit to cut out the cassette hole in the board: https://www.whitesiderouterbits.com/collections/1-2-shank-straight-bits/products/1073-01
It's going to cost a couple hundred to put this box in and do it right, but it should be the toughest option available!
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I would have probably sourced the same materials from the same places, or maybe used thinner D-cell layered with epoxy.
Be careful with that long router bit.
Will you be wrapping and capping the boxes with glass or carbon fiber?
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I would have probably sourced the same materials from the same places, or maybe used thinner D-cell layered with epoxy.
Be careful with that long router bit.
Will you be wrapping and capping the boxes with glass or carbon fiber?
I'm new to this, so any advice is appreciated. From the looks of other cassettes it looks like they just sink the boxes into the Divinycell with thickened epoxy, but I could be wrong. I certainly could wrap the boxes in something first. I have plenty of carbon and glass.
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+1 on the router bit being dangerous. That's easily the most dangerous thing in your house/shop. Don't want to spook you but just be cool and aware whenever that thing is live.
Glass wrap and cover the boxes if you can and it sounds like you are on the way to a bulletproof install.
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I hear you guys on the bit. My router is fixed at 25k RPM too, so yikes. I'm going to use shorter bits until I have to cut through the very bottom.. and then go REALLY slow. I'll probably armor up my body and face too to be extra safe.
By wrapping the boxes I'm assuming you guys mean that after I cut the slots in the Divinycell for the fin boxes that I first lay in and wet out some carbon or glass, and then shove the box down into the hole/slot over it? I suppose then I should take that layer all the way to the edge of the Divinycell on top?
Lastly, by glassing/carbon(ing) over the box you do mean when I put the final layers on for the board bottom skin that I cover the box openings with the layers (without masking off the boxes) and cut them open again after curing? This was my plan and I have a flush trim bit to accomplish this.
Thanks for the help!
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You don’t even need to mess with a router.
Multi tool to saw cut the skin.
Drywall saw to cut the EPS hole.
Gorilla glue to lock the divinycell in place.
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+1 on gorilla glue. The only time I use epoxy is with glass or carbon. Gorilla glue is superior in every way for gluing stuff to foam.
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How much does Gorilla glue exotherm? Any concerns with melting the EPS?
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No heat generated.
Gorilla glue is better than epoxy when the hole cut is less precise. It fills every void giving more complete bond.
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But don’t use gorilla glue between your divinycell layers. You don’t want expansion there.
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If you can bond ahead of time with the gorilla glue and apply pressure it should work.
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Since I'm going for bullet proof and I'm going to have tight fitting parts I'm going to stick with the epoxy. The big thing is that I might stick carbon around the cassette cut out and/or between the Divinycell layers. There shouldn't be any excessive gap to have to fill. If I line the cut out with carbon wrapped through to both decks first, any exotherm will be unable to get to the EPS too... not that I'm expecting that gap to be big enough to even exotherm much at all. I'm also using slow cure epoxy on that.
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There are a couple ways to think about it...
You can overbuild it and create additional stress points in the system or you can imagine how to best couple each member to its neighbor. We use D-cell because it is stronger than EPS. If you line that joint with fiber and resin, both foams may want to shear away from the rigid cloth. If you use GG, it expands into the porous foams and provides a connection with a little flex. So if you liken it to anatomy then it is fat muscle tendon bone to EPS GG D-cell finbox. I would do a layer of epoxy and cloth between D-cell and the box and for sure capping it ( the big foam insert) both sides and lapping onto the old skin. I do a mild version of this on my SUP finboxes to protect the EPS from taking in water if I smack a fin on something.
Will your plan work? Most likely Yes but you could be inadvertently adding some stress points.
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I hear you, I've been thinking the front and rear edges of the cassette I put in could cause strain points for the whole board breaking in half. Perhaps the better way to reinforce for this is to just add carbon/glass layers on the board surface which go continuously past the length of the cassette, rather than try to create an I-beam effect along the sides of the cassette, which will, like you said, increase point loading in the area. Interesting, I'm going to have to plan this carefully. How worried should I be about disturbing the sandwich skin of the board construction?... because I'm basically replacing it with a single skin attached only to the top skin of the boards existing sandwich.
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The cassette shouldn't be isolated from the rest of the board. I've done it that way and when I thought about it, regretted it. I was taking a good practice for inserts and applying it to foam cassettes without thinking it through. That's one reason Gorilla glue, which is both strong and flexible, works so well. Jrandy's explanation is excellent. The tracks themselves can have glass under them--they are much stiffer than the surrounding material and anything you do to support them and keep them from moving is good. A common failure for inserts is for them to work against the surrounding foam. If the foam is pushed to the point of yield it won't spring back, and the resultant void often causes delamination because there is no support for the insert other than the skin. The insert gets pushed down with mo support under it and breaks away from the skin. Presto, leak. Your cassette can probably just be set into the foam and attached only to the bottom. The surface area increase makes even the soft EPS capable of resisting a fair amount of force. Still better to tie it to the deck, but make the bond of PVC foam to EPS as resilient as the foam. Epoxy is hard and doesn't penetrate into the interstices of the foam.
EPS has a compressive strength of 10-60 psi. Even if your EPS is just 20 PSI the cassette has increased the surface area that is bonded from about 16 square inches for each track to what looks like at least 200 square inches for the cassette. And the PVC has a compressive strength of 200+ psi. Your tracks won't move in the PVC foam, and the cassette won't move in the EPS until you put a huge force on it. Tying it top and bottom to the glass takes the structure to another level. Belt and suspenders, and it doesn't cost anything in added weight unless you get as sloppy as I did with the carbon patches. Literally, you need a patch about an inch bigger than your cassette. My rail to rail carbon patch was just a waste.
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Too bad I'm not in Hood River, I have a box of 10" chinook mast tracks with maybe four missing. I think there's 25 in the box--but for all I know it might be 50. Anyway, a lifetime supply. Glad to give you a couple.
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Thanks Bill! This is all great info! By next week I'll have all my stuff and can get started.
All good on the inserts, I already have two coming from Jose at FiberGlassSupply. He also had a private stash set aside from when they stopped producing them.
I really appreciate the sharing of all the great wisdom and experience here!
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Thanks Bill! This is all great info! By next week I'll have all my stuff and can get started.
All good on the inserts, I already have two coming from Jose at FiberGlassSupply. He also had a private stash set aside from when they stopped producing them.
I really appreciate the sharing of all the great wisdom and experience here!
Stopped producing them...is this to say that Chinook does not have them, does not make these boxes at all, or now makes them at a different level of quality?
https://chinooksailing.com/collections/board-building-part-accessories (https://chinooksailing.com/collections/board-building-part-accessories)
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Thanks Bill! This is all great info! By next week I'll have all my stuff and can get started.
All good on the inserts, I already have two coming from Jose at FiberGlassSupply. He also had a private stash set aside from when they stopped producing them.
I really appreciate the sharing of all the great wisdom and experience here!
Stopped producing them...is this to say that Chinook does not have them, does not make these boxes at all, or now makes them at a different level of quality?
https://chinooksailing.com/collections/board-building-part-accessories (https://chinooksailing.com/collections/board-building-part-accessories)
I can't remember who, but someone I spoke with in my hunt for the fin boxes told me everyone stopped using the Chinook boxes in the past. I guess windsurfers went to tuttle/powerbox and everyone wanted lighter weight, cheaper boxes, like the futures/etc so production sounds like it came to a stand still out of lack of demand. Suddenly this foiling craze has come about and now everyone wants stronger boxes again, so they ran out of old stock and have kicked into production again, that's why they're backordered for a few weeks currently.
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Ok, I just about have all the parts needed to build my foil track cassette using Chinook fin boxes.
I have the RideEngine cassette (left side in photo), Two Chnook 10" fin boxes, and some 1" H100 Divinycell sheets. While I wait for more Divinycell to arrive I made a router template for the Chinook fin boxes to go into the Divinycell.
How much gap should I leave on either side and bottom of the boxes in the Divinycell? My template leaves a hair under 1/16" total on the sides as it is, pretty tight.
The Chinook boxes have 5/8" of material from where the T-nut holds and the top of the box. The RideEngine box has 1/2". So the Chinook boxes have 1/8" (25%) more thickness. They are all the same length and width. I'm going for strength on this one so that's the reason for making my own cassette with the Chinook boxes. However, this RideEngine box doesn't look bad, I will use it on a smaller board which sees less forces than my big board.
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I'm trying to figure out how best or even if I want to add the carbon to the Chinook boxes when they go into the Divinycell cassette. I'm assuming I'd just run one sheet of carbon over the whole cassette and then sink it down into the routed out holes when I put the boxes in? It's going to be tough to keep the boxes lined up right and get that carbon flat on the top surface.
What do you think? Is the carbon addition really necessary? I'm going to be putting a few layers of carbon over the whole thing once it's in the board, seems like it should be pretty tough, then again, I've never made one of these before!
The RideEngine cassette I have doesn't have this carbon bit, they just sunk the boxes right into the Divinycell using thickened epoxy... that's what I'm leaning toward, if not just because of the complexities mentioned above.
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I'd worry more about keeping the boxes parallel to each other and square to world than adding a lot of carbon fiber underneath them. It sounded like your rout was going to be pretty tight...maybe I'd just add one piece of wetted 4oz glass in the holes or go commando like the Ride Engine. Were you going to use one of your foils as an alignment jig for gluing in the boxes into the routs? How deep do they recommend setting those boxes?
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Yea, getting them square/parallel is something I've been thinking about for the past hour. So far what I've identified as possibilities are:
1. Bolt the boxes tightly to one of my adapters at the exact width and then sink them in as a unit with mylar between adapter/boxes with waxed up screws/nuts. The boxes end up flush with the top of the cassette this way too. I just worry about overflow getting down in the boxes or having no where to escape.
2. Sink the boxes in free and very carefully measure and use sticks to wedge the sides to get everything just right.
I like the first way because it's going to be damn exact, but I like the second way because there is space for the overflow to come out and I can scrape it away. What to do...
I think I'll skip using carbon under the boxes and go with glass, since it flexes a lot easier. I test fitted the carbon though, it fits fine, but not much extra space left after that.
I'm leaning toward the first way and maybe just make sure I'm a little short on the thickened epoxy so it doesn't overflow and fill the boxes up.
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I threw the aluminum CNC adapter (from Foilmount), for the most accuracy, together with the boxes and put a sheet of 0.01" Mylar aka PET (Polyethylene terephthalate) as a barrier between. Boxes exactly at 90mm apart. I think I'll just tape over the unclamped down areas of the box to avoid spill over and call it good. Bolts were waxed too just to be safe, but I don't see how they could get contaminated. Interestingly enough the bottoms of the Chinook boxes were not quite square after tightening it down to the adapter. I don't know what to think about this. Either the bottoms of the boxes are off (both off the same bit exactly) or the tops are off. Off by about .5 to 1 degree or so each, close enough I guess? I suppose the better way to be exact would be to have fins in both boxes and get them vertical and parallel... but of course doing it this way that's not possible.
I tested the fit in a test piece made by using my template and they drop right in both ways with only about 1/32 on all sides to spare, good fit!
I think I'm ready to go and do the final cut and fit.
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Don't post that on Swaylocks. The beards will start explaining why XPS will delaminate and how the expansion gases will rot your feet.
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Ok, ready to lock and load it in.... I guess I'll use 6oz glass and drop them in. Nice tight clearance so shouldn't need much thickened epoxy.
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Right on 'Supper.
I would add some baking flour to the boxes and cover the middle portion up with masking tape.
I got that tip from a Hawaiian uncle on Swaylocks who is also not afraid of XPS.
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Nice, is that a joke or for real? :)
I just covered the exposed box ends with tape, I'll have to chisel out any that gets by, if any does.
I was out of 6oz glass so used two layers of 3.7 instead. Currently curing with about 300lbs of granite and other random heavy shop items on it. It look a lot of weight to get the boxes to finally sink all they way down, the fit was pretty tight. I think I used a little over 100g of epoxy. Probably about 15-20% of it squished back out and I wiped it away.
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The flour trick is for reals and I have used it.
The aforementioned XPS-phobia is also real except for those who have already freed their minds.
A couple of these dinner tray foil boards would be good candidates for proving or disproving the theory.
Sounds like you may have been 1 layer too tight and a bit generous with the epoxy.
I probably would have done the exact same thing...
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^^My plan exactly. I think I could make a super light foil board with XPS. Maybe do some radical things like an internal skeleton and no skin other than the standing area.
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Ok, so too bad I didn't hear about the flour trick before I sunk it in. Not a major disaster, just had to chip out the spill over, and there was a bit more than I thought there would be. I happen to have just the right size chisel for the box width, some good hardened picks, and made a custom angled chisel out of a flat head screw driver (to clean the T-nut slot). In 30min it was like it never happened, easy recover, whew!
The tight fit was only because the gaps were so close around the boxes that the thickened epoxy had a hard time escaping, and all the glass in the way didn't help. There was no pinching as I test fit everything dry first. However, it came out perfect, the top skin is about 1/64-1/32, just enough to hit with some 80-120 grit for later skin attachment. There were no dry spots, which I was worried about, and everything is fitting great. All three of my adapters fit loose and slide smoothly to the ends.
Had to do over, I would definitely seal or create a non-stick surface in the box interior. The cassette is 200g heavier than the RideEngine at this point, although mine is 1/2" wider overall, is 7.4oz glass sunk/capped, and uses H100 (I think the RideEngine might be H80, it's not as dense/strong as the H100).
Now just waiting for a couple more 1" sheets of Divinycell to get the thickness I need and then in the board it goes!
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Yet another template to make. Too bad I'm not producing this work since I have all the templates now.
How exact should the cut out for the cassette be in the board? Right now it's a slightly snug fit in the template. I can lightly press the cassette into the template and it has just enough friction to hold the template up at the top of the cassette. I'd imagine minimal adhesive will be used with this tight of a fit. From the sounds of it, maybe this is a good thing as the harder adhesive can create point loading between the foams. Thoughts?
Other than that, looks like I'm ready to route out the board with this crazy long bit <cautions noted>.
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Which adhesive, epoxy or Gorilla Glue?
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Which adhesive, epoxy or Gorilla Glue?
I'm going to go with what I know, thickened epoxy. I'm thinking keep the gap low so less chance of exotherm meltdown. Slow cure hardener as well.
I'm too worried about the power of expanding adhesives causing destructive results, which I have seen before when it gets confined.
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I can understand the concerns and the desire to stick with 'the devil you know'.
I think you'll succeed either way but my preference would be GG at this point, mostly because it is closer to the density of the surrounding foams and will expand and fill in the directions that you are not able to clamp.
Dampen the foam, apply the glue thin and even with a spreader, slide the cassette home foil side towards the bottom...or mix the water in Beasho-style and go from there. Being that it is a square peg in a square hole with a tight fit the amount of glue becomes somewhat self-limiting.
Looking forward to more progress pics.
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OK guys I'm done joking around here. EPOXY is inferior for large box installations.
Here is evidence from YESTERDAY. My brand new L41 Tuttle box just melted away inside the board after just 7 sessions.
I cut out the box and find it looks like A BRAND NEW INSTALLATION. When I cut the skin around the Tuttle box it practically fell out into my hands. Whoever did the installation used epoxy.
I am somewhat surprised because these boards typically come out of Stretch's shop and he taught me to use Gorilla glue.
There is NO CHANCE THAT A GORILLA GLUE INSTALLATION WOULD HAVE COME APART LIKE THIS. The divinycell would have been 100% adhered to the foam and the failure would have been MUCH, MUCH more catastrophic.
The epoxy is visible along the walls of the styrofoam, and CLEARLY DID NOT ADHERE TO THE DIVINYCELL.
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From the TOP deck there is a significant amount of delamination around and forward of the front bolt. This makes sense given the center of Lift and the Center of Mass all forward on the foil.
The moral of the story is to consider these forces when reinforcing the DECK and BOTTOM of the board.
1) Make sure the box is secure in the foam. If it is you are getting 80% of the problem solved. The incredible vertical load needs to be suitably distributed from the foam to the shell structure of the board
2) The upper and lower surfaces need to be mechanically stable. The thin strip of carbon on this board combined with the EPOXY installation was doomed to fail. This is where carbon patches on top and bottom of the board become paramount. How big they need to be ???? Eventually time will tell.
Fortunately this should be a pretty quick repair because it's almost like a clean, new installation all-over again.
I'll just follow my lead from the last box that blew up and then held up for 600+ waves. My first Tuttle box failure was more terrible but it never failed again. See repair here:
https://www.standupzone.com/forum/index.php/topic,32837.msg370284.html#msg370284
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Holy sheit! Major bummer on the new board!
Ok, this warrants some testing now. I'm going to glue some spare Divinycell to some EPS/XPS and fiberglass and then see how good the bond is using both thickened epoxy and Gorilla glue. Test results don't lie.
I'm not sure what kind of Divinycell was used in that box, but it doesn't look like the stuff I'm using.... it almost looks like some kind of high density XPS?
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The adhesive and the foam must be only a small part of the issue. It's purpose is to hold the fibre in place for when the loads come and take on minimal force itself. I think much more attention has to be paid to the transition from the box to the deck laminates. It all seems wrong to me: beefy box in Y axis meets thin deck in X & Z axis with essentially no transition. The post with the plywood stringers on either side of the box makes a ton of sense - if the ply had fibre reinforcement.
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Another factor in my case is that I'm putting in a 12" x 6.5" track box cassette, not a 2" x 7.5" tuttle box cassette (measurements taken from my Waterat tuttle box). I calculated it to have twice the surface area in the sheering axis. That said, if the PU glue is stronger, then it will be twice as strong too if I use that. I guess the point is, maybe it's less critical in my case. The track box will also have twice the perimeter contact length. My board is sandwich construction as well. I will be doing full carbon contact overlaps with the top and bottom skins. There is a lot going for mine in the strength department, but I'm going to run some tests as I'd like to use the strongest way possible.
The only other factor I need to work out is what to do about sinking the box in with regards to the V and rocker, as there is some of both, mostly V. I guess try to get the two fin boxes level with the normal bottom surface of the board? That would mean, sunk slightly low in the middle of the cassette, and slightly high on the outside. The top of the cassette itself needs to be flat for my foil mounts though, hmm, that's going to be interesting. I guess there will just be a little flat spot where the cassette is, no big dill.
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Alright, did my most fearful part, cutting out the hole in the board for the cassette. Whew, glad that's over with. Using that 5.5" router bit was scary. I made sure to be extra careful. I kept a lot of material between me and the bit at all times and doubled up the eye protection. I can't believe something that long can spin that fast without breaking. I only used the long bit to cut the foam, and to just plunge holes through the top of the board from the bottom. I dared not try and sweep through the template with 4" of bit exposed at 25k RPMs to cut the top of the board out. I plunged a bunch of holes and then just sawed between them and sanded it back to the right size.
Now just waiting on my last two sheets of 1" Divinycell so I have the right depth. It's a really good fit, not tight at all, but only about 1/32 to 1/16" play at most in any direction. Very happy with the outcome. I noted that the bottom skin of the board, where the old FoilMount was mouted, was somewhat delaminated and the skin came off fairly easy after being cut around the edges. The skins on these wood sandwich boards are so thin! It's amazing the abuse this board as taken over the years and not broken or delaminated yet!.
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One more thing I wanted to add and caution other about... they used about 1 inch long stables to keep the wood nailed down to the core for when they put it on the mould, I got super lucky and just barely missed these things! Yikes! Careful out there routing sandwich construction boards!
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Yes, I'm done with using epoxy for inserting anything into a surboard. Gorilla glue is a superior method and most importantly, doesn't melt EPS. I don't know that Beasho's board would have fared better, the strength of EPS is really low. Binding the box to the bottom and deck is critical, and that means you need lots of strength in the deck and bottom.
Shark--the Divynicell around the GoFoil box looks like that. It's some kind of castable PVC foam. High density, high strength. It's a bitch to cut.
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First test, I took a 1" x 3.5" x 12" piece of Divinycell and glued it on end to a piece of blue XPS. The XPS was sanded with 60 grit to get rid of the super smooth finish it comes with. I also took a 1" x 3" strip of fiberglass and ran 1" of it under one side of the connection. After the XPS separated I wanted to see how hard it would be to pull the fiberglass off the Divinycell. Straight epoxy was used on the fiberglass part and thickened epoxy used on the rest. Mixed 1 to 1 with microballoons. I pressed the epoxy into the foams with pressure to get the best penetration.
I let it cure for a day. The destruction test was to hold the XPS vertical and weight up the end of the Divinycell with weight to see how much it would hold. I had two 8lbs iron press shims to use.
The joint felt very strong, more than I thought it would. It took the first 8lb weight with no issues. I added the second block, which made it almost 16lbs. Amazingly it held for about 30-45seconds. Just as I was about to snap a picture it let go finally.
Here is how things failed, the XPS being the weakest link broke first. The XPS sheared off at the depth the epoxy penetrated the foam. I pulled the fiberglass off the Divinycell, which came off easier than I would have thought. In this case the Divinycell sheared to the depth the epoxy penetrated into it.
Two things that surprised me. One was that the joint held so much force! 8lbs at 12" out against a 1" x 3.5" surface is pretty dang tough! XPS is quite strong. The second surprise was how weak the join between fiberglass and the Divinycell was. It didn't take that much effort to peel it off. I had extra saturated the glass and Divinycell with epoxy, but the Divinycell gave way without a huge amount of force.
After this test I'm not too hesitant to use epoxy to put the box in, from a strength perspective, but heat, that's another thing... next I'm going to get some Gorilla Glue and do the same test.
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The second surprise was how weak the join between fiberglass and the Divinycell was. It didn't take that much effort to peel it off. I had extra saturated the glass and Divinycell with epoxy, but the Divinycell gave way without a huge amount of force.
As I am cleaning up the box on my board for repair I am finding the same thing: The Epoxy, which is pretty flexible in some cases, peels away from the divinycell cleanly and in some cases very easily.
On the inner walls of the EPS the Epoxy is also peeling away semi easily. This was more surprising because I thought it would just rip the EPS away.
It will be interesting to see how the Gorilla Glue performs in this test.
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Wow this Gorilla Glue is foam stuff! Kind of a pain to mix with water, I see why you use the dremel.
The Gorilla Glue is going to have a slight advantage in that the surfaces are at least twice as rough as with the epoxy. But this stuff didn't spread as wide, so we'll see. This test isn't anything exact, just to get a general idea of how strong each is in different ways.
I'll give this overnight to harden and test it tomorrow.
In the meantime, my last two sheets of Divinycell showed up today, so I will be ready to put the cassette in soon!
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Hate being the crank here, but what are we going to find out? the XPS will give way, then you can peel off the adhesive from the HD foam. The stronger the adhesive, the faster the foams will yield. The weak point in these tests is the foams.
But the weak point in the installations is the skins as they clearly can't take the loads unless better distributed. I think Scubasteve is on the right track, so to speak. Some biaxial fibre might be well placed on those short stringers he installs. Or use thin HD foam with fibre on each side instead of plywood.
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Yea, I hear you, this is not a super meaningful test. I just haven't used Gorilla Glue before with foam, so I wanted to just get a quick idea of it's relative benefits/downsides, as well as a general idea of how strong it is compared to other options. A few people are highly recommending it for putting the cassette in the board. I'm just about to do that, so I want to pick the best option. I'm going for ultimate strength on this one.
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I use a 2 part Expansion foam - works great.
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I was wondering about that. I have this TAP X-30 stuff: https://www.tapplastics.com/product/repair_products/foam_insulation_materials/tap_x_30_polyurethane_foam/79
I could use that. I just can't remember if it has a strong exothermic reaction. Also, according to Beasho's testing the Gorilla Glue is 4lb density, and the X-30 PU foam is 2lb. Maybe I'll run a test with that stuff too then.
The one thing I don't like about the PU foams is that the time to adjust things is much shorter.
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Inquiring minds want to know. How is the XPS test coming?
I went out and bought some XPS for my own testing.
Meanwhile here is the state of my box repair: The Tuttle Box has been cleaned of all loose epoxy. There were a few cracks in the divinycell that were repaired with Gorilla Glue.
The delamination area, on this upper deck surface, were underpinned with Gorilla glue and then loaded up with weight. The Gorilla glue was mixed with water using the Dremel trick. The resulting medium looks whiter than the original Brown Orange. The foam expands and in the forward box area formed a perfectly clean Fill Layer under the vinyl. Almost so smooth I will probably have to sand it.
I have chosen to keep as much material as possible rather than ripping off all the skin. The savings in weight would be minimal and require me to build up a great amount of material. I am planning to set the box with Gorilla Glue (using the added water trick). Then 2 X 6 oz E-Glass covered by 2 X 6 oz of Carbon on the Top and the Bottom areas of the board.
I am more convinced that the box was simply floating in the foam. The Epoxy job was either 1) Poor or 2) Just DID NOT ADHERE to the Divinycell.
There is SIMPLY NO WAY WITH THIS TIGHT FIT THAT GORILLA GLUE WILL FAIL like the epoxy did between divinycell and EPS.
My small patches of Gorilla Glue are sticking like Mad to the divinycell. Then again I did the original test to show that the Gorilla glue will adhere and prove stronger than the Divinycell itself.
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References to XPS being used with Gorilla Glue on Swaylocks. The trick will be to whip in the the moisture by mixing so that the glue cures in an airtight / moisture free environment.
I have found that excess Gorilla Glue is easily cut back with a sharp knife.
https://www.swaylocks.com/forums/xps-glue-warning
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Wow, you get really nice even density with that whipping trick. Mine has lots of air pockets and large bubbles within. I like how you used the non-stock, I thought the Gorilla Glue would stick to anything! Good to know!
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I ran the Gorilla Glue test through destruction. Before I explain how it went I just want to reiterate that this test is just roughly messing around, nothing super exact about it. Its mostly just has some value to me to see about what the relative strengths and weaknesses are of epoxy vs Gorilla Glue used to adhere two pieces of foam together.
I have to say, I was doubtful of the Gorilla Glue up until I tested it. My doubts were further supported when I felt how soft the bubbly Gorilla Glue "foam" was after expanding and hardening. I just couldn't see how that stuff could be very strong. However! It passed the 8lb load fine, no issues. It did fail on the 16lb load, and quite quickly, faster than the epoxy, but the epoxy was spread a lot further out on the XPS creating more surface area for it to adhere to... of course the epoxy being a more hard/solid structure allows it to do that, whereas with the Gorilla Glue it would not matter too much how far out you spread it as it's pretty soft stuff when not contained tightly between two surfaces.
The XPS was what gave way as expected, however, it's obvious the penetration of the Gorilla Glue into the XPS was much more significant than with the epoxy. I know the surface was definitely rougher on both the Divinycell and XPS for the Gorilla Glue test, but still, it actually broke a piece of the XPS out of the core! The rest of the Gorilla Glue, which was not contained between the two surfaces was pretty useless in adding strength, which actually is even more impressive! I think of it this way... the epoxy had probably 4-5 times the surface area to adhere to on the XPS side due to how far it was spread out and how hard the epoxy gets. Whereas the Gorilla Glue effectively just had the single 1"x3.5" surface area to adhere to the XPS. Even through the Gorilla Glue failed first, I have to say, if I did this test using only enough adhesive to cover the 1"x3.5" area between the foams, it seems pretty clear to me the Gorilla Glue would have been stronger. Very impressive stuff!
That said, in my case I'm putting a cassette/box in a board with up to maybe 1/32 to 1/16" gap on the sides. I don't think the situation is the same as in my test. Seeing how soft and much weaker the foamed out Gorilla Glue is when not contained tightly between the surfaces, I'm not sure it would actually be stronger than other options given the gap. Without the gap, no question though, but that's not what I've got. That doubt, which is all it is, just a guess.. along with the fact that I don't think I can get my cassette wetted out, installed, and aligned properly before the Gorilla Glue kicks off, leaves me still probably going with the epoxy. However, I have now seen the advantage of having a very rough and uneven surface to adhere to. I think I will scratch up my foam surfaces really good so I get the extra penetration and contact area to make it stronger, even if I'm using the epoxy way which may in fact be weaker in some ways.
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This kind of experimenting is what makes garage builds so much fun.
The disagreements they spark make the internet fun.
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I use the 2 part polyurethane foam from US composites works great and holds up. this board had no HD block with the mast tracks so I had to remove and replace, made my own HD block and set new chinook tracks.
(https://i.imgur.com/nyWY0KYl.jpg)
(https://i.imgur.com/AddPYpgl.jpg)
He sent me these pics right after and has been flying high with no issues
(https://i.imgur.com/zG1CxrBl.jpg)
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It's amazing how people can look at good data that contradicts what they think they know, and simply not change their minds. I'm not singling you out Sharksupper--it's a topic that is very much on my mind these days. I'm reading the late, lamented Hans Rosling's book "Factfulness" concerning the ways that people are so very wrong about the state of the world, and how people will not relinquish ideas that are completely wrong about issues like overpopulation, poverty, immigration, education, and the value of reducing infant mortality in the "third" world (which really isn't the third world at all). And I just finished reading "Reality Is Not What It Seems" by Carlo Ravelli. Contemplating loop quantum gravity is not a good pastime for people who insist on being right about anything. Anything, as in absolutely anything.
I've also tested using Gorilla Glue for inserts into foam. I was more interested in seeing how it performs in those applications since I consider the elimination of exothermic reaction to be a critical advantage. I don't care much about how it performs in shear, though it might be an interesting thing to know about. I glued Greenlight 1 inch leash plug inserts into two pound EPS and then yanked them out using a hand winch (come along) and my handy-dandy load cell contraption I built from a twenty buck digital scale that I use for drag testing. I put a piece of plywood with a 1 1/2" hole over the leash plug to simulate a skin (sort of) and pulled the plugs perpendicular to the board. I didn't write down the results, it was just for my general knowledge, but roughly for five pulls each of Gorilla Glue vs Resin Research slow epoxy mixed with microballons. Gorilla Glue broke out at a surprising 60-80 pounds, epoxy at 40-50. In both cases, this was a lot higher than I expected. The tensile strength of two pound EPS is supposed to be about 60PSI.
In any case. I'm convinced Gorilla glue is substantially stronger (roughly 2X) for inserts than epoxy, and adding too much won't create a burn cavity. I still use epoxy when I glass under a big insert such as a mast track being added to a completed board, but I don't know whether or not I'm coming out ahead when I do that. I'll test it sooner or later.
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I use the 2 part polyurethane foam from US composites works great and holds up. this board had no HD block with the mast tracks so I had to remove and replace, made my own HD block and set new chinook tracks.
You made the HD block from the pour foam? I was considering this as an alternative to 100 dollars worth of divinycell.
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I use the 2 part polyurethane foam from US composites works great and holds up. this board had no HD block with the mast tracks so I had to remove and replace, made my own HD block and set new chinook tracks.
You made the HD block from the pour foam? I was considering this as an alternative to 100 dollars worth of divinycell.
Out of Divinycel, had to buy a sheet. Where are you getting it for $100?
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It's amazing how people can look at good data that contradicts what they think they know, and simply not change their minds. . . .
I've also tested using Gorilla Glue for inserts into foam. . . .
In any case. I'm convinced Gorilla glue is substantially stronger (roughly 2X) for inserts than epoxy . . .
Enough said!
I'm with you Pono but this is coming from a guy who makes his own leashes, repairs almost everything and roughs people up in the corporate world with their own data. The fin box was the last stop in the Galaxy that I was reluctant to tackle. Then I did a few Pro-Box installations, burned some of them out with the exothermic epoxy reaction . . .
I have some Tesla kids (e.g. 32 year olds) down the street that are exceptionally good engineers. This means the data overrides the emotion. They also fix surfboards and concluded "why can't you install a fin box with just Gorilla glue?" (and then laminate with epoxy of course)
The reason my Tuttle box fell out was because of VOIDS. Not because of the poor strength of Epoxy. Epoxy is a liquid and it runs. The only way to get it to 'hold fast' is to create a humongous pool of liquid and keep it contained. You could create an entire surfboard filled with liquid epoxy and it would be BOMB proof. But it would weigh 200 lbs. (about the density of water).
Surfboards are SHELL structures. The strength is in the skin. EPS has some strength but probably not enough to handle a 3/4" wide Tuttle wiggling around so they make the base larger with divinycell to distribute the load to a broader surface area of EPS and Skin. Given the larger Tuttle cassette you are only concerned with good adhesion to the deck and to the foam.
In my failure example the epoxy being 50X stronger than EPS didn't get me anywhere because the epoxy dripped away leaving voids with a shear strength of exactly ZERO.
Gorilla glue has proven:
1) Significantly stronger than EPS
2) Eliminates all voids by expanding into all the microcavities
3) Is much, much lighter than Epoxy
What more could you ask for?
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Serious thread creep, but I have three important book recommendations for you Beasho. The first is obviously Hans Roseling's Factfulness. You'll love it. It's about using data intelligently and how far off common knowledge is from reality. Pretty much explains the entire Trump phenomenon and the dumbing of America. Might be worthwhile getting it as a paper book since the charts and graphs are bitchy in the ebook--they should be links, but they aren't. I think people would view this as a way to change how they look at the world from a humanitarian perspective, but really it's a competitive advantage book. If I'd had this when I was running my agency we would have ruled international marketing.
The second is "The Hard Thing About Hard Things". You might have already read it. It's another book that would have been worth almost any price to me when I was running my company. Talk about missed opportunities. I did well, no complaints, but another zero or two would have been nice. I certainly would have added at least one if I'd had this book. If you bump into a dumb or passive CEO that doesn't know what he doesn't know, buy him/her this book.
And finally, "Reality is Not What It Seems. Yes, it's Physics, but it's also a transformation for thinking about reality. Brilliant book. I read it, then bought the audible version and listened to it. When I finished listening I started over again at the beginning. I already think I might loop it three times.
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I bought my Divinycell here (the 1"x6"x10" pieces): https://www.standupzone.com/forum/index.php/topic,33404.75.html
Now sitting here with a 2lb+ brick of Divinycell and fin boxes, and looking at the light weight EPS and thin skin on my board, it sure does seem like overkill, massively. I really like that pic from eDUBz of the tracks being put in with PU foam! I think in my case I could have done with just two sheets of the Divinycell where the boxes go in, and then just filled the rest with Gorilla Glue and/or XPS... saving the weight for adding more carbon to the skin layers. The Gorilla Glue would have been great in that case because then I wouldn't have the issue I have now which is that I can't get the cassette in place faster than the Gorilla Glue foams up, which is the one downside to it that I see. You get less than 60 seconds after properly mixing, before it goes off. It took me a few minutes just to get my cassette in the board and aligned correctly, and that was rushing. If they made it so it kicked off slower that would help a lot. I think all the liquid PU foams kick off super quick too. I'm just not skilled enough to take the chance at gluing my cassette in the board when it's not all the way in or aligned right. I wish I had more experience with it. I'm certainly not looking forward to possible exotherm destroying the whole thing with epoxy. In fact, I'll be doing a test between two sheets of XPS at the same thickness the epoxy will have with my box first, just to make sure I'm good.
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Shark, for myself, "a picture's worth a thousand words", so here's Dave Daum of King's Paddle Sports putting in his own "King Tut" box with Gorilla glue, and a spray bottle of water....
https://www.youtube.com/watch?v=M7v4pEgQrZg
Notice that he has way more than 60 seconds of positioning time in the clip...and he's got quite a number of foil boards out there now, and to my knowledge, has not had a single box failure as of yet (hope that doesn't jinx him now :().
Here's the cameraman above, and that board in that in action from yesterday...
https://www.youtube.com/watch?v=KVQuCXMVNs8
(Shoutout to "StandinDan" for the aerial footage).
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You don't have to do the premix with a large surface area, tight fit like yours. Just butter the parts with gorilla glue. Then use a spray bottle to soak the Gorilla Glue down with water and put the parts together. That way you have at least ten minutes to play around and get the fit perfect.
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Ah! This is the bit I was missing. I thought you had to mix the water in with it so it foamed up right. Awesome, I might just be able to do this after all. I'm just going to run one more shear strength test with epoxy vs gorilla glue to solidify my understanding of how it's going to work and then if all goes well have at it! Thanks guys!
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Not that this video applies to what I'm doing, interesting none the less: https://woodgears.ca/joint_strength/gorilla_glue.html
I would imagine that as the gorilla glue foam gets thicker (between the parts it's gluing) it's shear strength reduces significantly.
In the case of gluing foam, I'm sure it's less of an issue though, since the foam is relatively weak already.
Just to prove this for myself I want to glue two pieces of XPS together with a 1/16" gap using both Gorilla Glue and thickened Epoxy and see which has a high shear strength. My thought and hope would be the Gorilla Glue, but I just want to see if it's stronger than the XPS once it's filling a gap as wide as 1/16".. which is about the average gap I have to fill... some parts less some parts more.
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My thought and hope would be the Gorilla Glue, but I just want to see if it's stronger than the XPS once it's filling a gap as wide as 1/16".. which is about the average gap I have to fill... some parts less some parts more.
The Gorilla Glue doesn't have to be stronger than the XPS for the last 1/16" just stronger than the EPS. Eventually all the load is going to the EPS who cares about the final 1/16".
Just to pile on: Less moisture will kick slower. Raw gorilla glue will dry well against EPS with just a few topical sprays.
I put my box in yesterday and had ~15 minutes to work with.
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Out of Divinycel, had to buy a sheet. Where are you getting it for $100?
I've never actually bought any, it just seemed from quick guessing while looking at the Fiberglast website that about 100 dollars worth would end up in my board if I went that route.
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Out of Divinycel, had to buy a sheet. Where are you getting it for $100?
I've never actually bought any, it just seemed from quick guessing while looking at the Fiberglast website that about 100 dollars worth would end up in my board if I went that route.
You can spend a hundred bucks in a hurry on Divynicell. I generally buy it in 1/2" X 32" X 48" sheets and layer it. I think I pay about 60 bucks each for quantity five or ten. My memory sucks.
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Ok, so I've been stalled on getting the box in the board. Lots of wind, too cold for epoxy, nothing but excuses! :D
I was 90% ready to go with the Gorilla Glue, but my final affirmation test, which I expected to go without any surprises, had an interesting twist!
I very coarsely (with an 80 grit sponge) sanded XPS on two opposite mating sides and then used balsa wood a few inches apart at 1/16" thick to see how both Gorilla Glue and Epoxy faired in a balance of both bonding strength and gap filling together... as is the case with putting in my cassette. I basically just wanted to see if the awesome bonding characteristics of Gorilla Glue still held true when gapped out a little bit. I actually did this test pretty methodically. Both pieces had a 3" square mating surface, everything was the same. I used a very thick lather of Gorilla Glue (roughly a tablespoon each) on both surfaces, pressing it into the surfaces hard with my fingers and then sprayed it once really good with water on both sides. On the epoxy front I mixed it much thicker with microballoons than I ever had before, by accident. I really thought I was wasting my time with this test because at first the epoxy was so thick with microballoons it actually wouldn't even stick to the foam! It was the thickness of those peanut butters than almost bend your butter knife trying to mix! I actually broke a 1" tongue depressor just trying to mix it. I ended up having to really work it into the foam with my finger tips until it finally penetrated and held some surface tension... then I just flooded the gap with a pile and squished the XPS together. I was also testing to see if the epoxy would melt the XPS in this test.
The Gorilla Glue foamed up and outside of the gap as expected within 3-5min. I let everything sit for several hours and then tried to pry the pieces apart from the sides. I did not slice into the Gorilla Glue gap with anything like that, I wanted it to naturally fail when being pulled directly apart. When it did, to my huge surprise, most of the Gorilla Glue "foam" in the gap had failed before the XPS! I am really shocked at this result, but that's what happened. You can see in the picture how a few small places let go on the XPS on either side, but most of it gave way within the Gorilla Glue foam gap itself. I also didn't twist this piece to break it, I literally pried it from the unglued end until something broke.
Despite this result, I still thought the epoxy had probably done worse. Again, another surprise! The XPS broke first in about a half inch thickness above the epoxy layer! I wish I had snapped the pic before I further destroyed the piece, but I wasn't expecting to have to take pictures of this test, I thought I knew what the result would be. Even though the epoxy worked well, had to do over again, I would use some unthickened epoxy and spread it thinly around the surfaces for penetration first, then fill the rest in with the thickened stuff.
I don't know what to say, the Gorilla Glue seems to have great bonding strength when there is no gap, but leaving a gap allowing it to foam up between seems to be much weaker. This test was done with very dense XPS, so on EPS it's probably not going to fail first, but still interesting to learn this glues properties, what it's good at and what it's not as good at.
My XPS didn't melt, and the Gorilla Glue didn't hold as well, so I'm going with the epoxy based on my testing results, not because that's what I've always done (I've never done this before, first time! ;) )
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Couple of notes.
Edubz is using divinycel the pour foam is replacing the epoxy or glue.
Second, I'm not sure that a "few hours" is enough for a PU glue. Most say 24 hours til full strength but you do you man. It'll be fine. There's a lot more foil mounts working out there than breaking.
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Cool, maybe there's something new to learn there.
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Out of Divinycel, had to buy a sheet. Where are you getting it for $100?
I've never actually bought any, it just seemed from quick guessing while looking at the Fiberglast website that about 100 dollars worth would end up in my board if I went that route.
You can spend a hundred bucks in a hurry on Divynicell. I generally buy it in 1/2" X 32" X 48" sheets and layer it. I think I pay about 60 bucks each for quantity five or ten. My memory sucks.
I know, I get mine for $140
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Couple of notes.
Edubz is using divinycel the pour foam is replacing the epoxy or glue.
Second, I'm not sure that a "few hours" is enough for a PU glue. Most say 24 hours til full strength but you do you man. It'll be fine. There's a lot more foil mounts working out there than breaking.
Yes, divinycel block. I’ll make the block first and use the 2 part PU foam to set it. I’ll that cure and come back and install the mast tracks.
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Ok, so I've been stalled on getting the box in the board. Lots of wind, too cold for epoxy, nothing but excuses! :D
I was 90% ready to go with the Gorilla Glue, but my final affirmation test, which I expected to go without any surprises, had an interesting twist!
I very coarsely (with an 80 grit sponge) sanded XPS on two opposite mating sides and then used balsa wood a few inches apart at 1/16" thick to see how both Gorilla Glue and Epoxy faired in a balance of both bonding strength and gap filling together... as is the case with putting in my cassette. I basically just wanted to see if the awesome bonding characteristics of Gorilla Glue still held true when gapped out a little bit. I actually did this test pretty methodically. Both pieces had a 3" square mating surface, everything was the same. I used a very thick lather of Gorilla Glue (roughly a tablespoon each) on both surfaces, pressing it into the surfaces hard with my fingers and then sprayed it once really good with water on both sides. On the epoxy front I mixed it much thicker with microballoons than I ever had before, by accident. I really thought I was wasting my time with this test because at first the epoxy was so thick with microballoons it actually wouldn't even stick to the foam! It was the thickness of those peanut butters than almost bend your butter knife trying to mix! I actually broke a 1" tongue depressor just trying to mix it. I ended up having to really work it into the foam with my finger tips until it finally penetrated and held some surface tension... then I just flooded the gap with a pile and squished the XPS together. I was also testing to see if the epoxy would melt the XPS in this test.
The Gorilla Glue foamed up and outside of the gap as expected within 3-5min. I let everything sit for several hours and then tried to pry the pieces apart from the sides. I did not slice into the Gorilla Glue gap with anything like that, I wanted it to naturally fail when being pulled directly apart. When it did, to my huge surprise, most of the Gorilla Glue "foam" in the gap had failed before the XPS! I am really shocked at this result, but that's what happened. You can see in the picture how a few small places let go on the XPS on either side, but most of it gave way within the Gorilla Glue foam gap itself. I also didn't twist this piece to break it, I literally pried it from the unglued end until something broke.
Despite this result, I still thought the epoxy had probably done worse. Again, another surprise! The XPS broke first in about a half inch thickness above the epoxy layer! I wish I had snapped the pic before I further destroyed the piece, but I wasn't expecting to have to take pictures of this test, I thought I knew what the result would be. Even though the epoxy worked well, had to do over again, I would use some unthickened epoxy and spread it thinly around the surfaces for penetration first, then fill the rest in with the thickened stuff.
I don't know what to say, the Gorilla Glue seems to have great bonding strength when there is no gap, but leaving a gap allowing it to foam up between seems to be much weaker. This test was done with very dense XPS, so on EPS it's probably not going to fail first, but still interesting to learn this glues properties, what it's good at and what it's not as good at.
My XPS didn't melt, and the Gorilla Glue didn't hold as well, so I'm going with the epoxy based on my testing results, not because that's what I've always done (I've never done this before, first time! ;) )
Seems like this test was seriously flawed. You mixed the epoxy to an unusable thickness. I am guessing you added too more curing agent then the 50/50 ratio? More curing agent will speed up the curing time. You also did the did not let the Gorilla Glue enough time to bond and cure which is 24 hours.
I am not trying to persuade you to use Gorilla Glue. However others may read this and be influenced by this test.
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Yea, who knows. I waited until the epoxy was hard, about 10-14hrs. Both were hard as a rock. Epoxy was mixed 5:1 to the nearest 0.01g, no mistake there. I just added too much microballoon to the mixture and it was a bit thick.
The test isn't exact, no, but it was enough to show me the Gorilla Glue looses most of it's strength when there is a gap (versus no gap, like in my first test). In this test it was 1/16" gap. The foaming action of the glue put so much air into the gap that very little glue was actually adhering the two surfaces being glued. The density of the foam was all over the place, some huge bubbles 1/2 wide in places where there was no glue connecting hardly at all. It wasn't because I didn't put enough in there, it foamed out all over the place on the sides. All this could just be how you use it, I just might not have the technique down. I would never make any recommendation off just one of my limited tests/experiences, so please, if you're reading this, go do your own practice tests and see what works best for you, that's all I did here. Just sharing the outcome so you understand why I made the choices I did.
In the end it would have been fatal to the project if I had gone with the Gorilla Glue... I took the full 1-2hr working time with the epoxy to get the box put in with proper alignment, I was so happy I had all that working time! I worked near the minimum temp of the epoxy and thermals never got about 78F. Currently curing...
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I pulled all the masking off just before it got too hard for easier clean up later.
I kept the box recessed just a bit below the bottom surface of the board to allow sanding of the surrounding board surface to take the laminates.
I was planning on 3-4 layers of carbon and maybe one glass sanding/anti-pinhole layer per side. I was thinking each layer would go 3/4" to 1" wider than the box/the previous layer on all sides. Maybe angle the front and back cuts so it doesn't create a straight across the board stress point.
Any suggestions?
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You went all the way through with the PVC Block?!
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I did one carbon 5.7oz Carbon patch - and 2 6oz glass with relief cuts as you mentioned.
(https://i.imgur.com/LP570Iql.jpg)
(https://i.imgur.com/s2aXhxPl.jpg)
(https://i.imgur.com/7am0JuMl.jpg)
(https://i.imgur.com/MNsUEnJl.jpg)
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I like to cover a large area as the final layer - this board I did 3/4 layers of 4 oz with unidirectional Carbon center and the cover entire in 6 oz
(https://i.imgur.com/G9IZHU4l.jpg)
(https://i.imgur.com/HZ6cKNll.jpg)
(https://i.imgur.com/eRSXgTRl.jpg)
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You went all the way through with the PVC Block?!
Oops! I thought that was the idea? Is that not right? Did seem kind of heavy, whole cassette was about 2lbs. Should be strong, yea?
How do you keep the epoxy out of your tracks when you glass over them?
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It’s not wrong just more work - I never did the cassette that way just the tuttle boxes. You can tape the mast track off and glass right over. Razor it out right before the epoxy hardens.
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I don't know what to say, the Gorilla Glue seems to have great bonding strength when there is no gap, but leaving a gap allowing it to foam up between seems to be much weaker. This test was done with very dense XPS, so on EPS it's probably not going to fail first, but still interesting to learn this glues properties, what it's good at and what it's not as good at.
I thought I had covered this issue in my video but I didn't show the results of cutting open the Cup-o-Gorilla-Glue.
When you whip in the water the density becomes MUCH, MUCH more consistent. The Gorilla glue cures with moisture. In a dry environment the glue will foam up, with internally generated gas, until it finds moisture. Then it will form a hardened layer. If you test it you will see the external foam layer is way stiffer and more dense where it 'found' moisture in the air. When you mix in the water, and whip the Gorilla Glue until it turns white you get a very consistent, bubble free internal foam structure. This is key to getting the best density and mechanical strength from the Glue.
To be fair an Epoxy install can work but it takes a good to great craftsman to pull it off. The Gorilla glue leaves far less of a chance for the installer to screw it up. This is coming from my experience with a "Professionally" installed box that failed in 7 days in a brand new board. The failed box was installed poorly with Epoxy.
https://www.youtube.com/watch?v=UgZ3A3igBbY
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Wow, that is a nice outcome Beasho! Much more consistent than how mine came out. I guess that's the difference then, you have to really whip it up with water, and not just with a stick, but with a machine. I guess then that does limit it's use to the 10-15min period before it kicks off, since the water is in it already. I tested the way I did (no pre-mixed water) because that's how I was going to do it on my board. I wanted the extra time to smear it on all the surfaces (lots of surface area with a track box!), and have plenty of time for alignment. Mind you, this is my first time putting in a box, so I'm stupid slow at everything. The water mixed in ahead of time would not have given me the time I needed to get the alignment right. The way it was I barely was able to get everything right with the epoxy at over an hour. I really struggled, it was the most stressful part so far! I wasn't even sure it came out straight, as it's not as easy as sticking a tuttle fin in the box, mine is a track. This morning, now that the epoxy is cured, I checked the alignment and I'm happy to say it's spot on! Super stoked! The strength already, without the glassing top/bottom is amazing, no flex at all.
The one downside I've learned (which I knew about ahead of time but didn't think it would be so huge) with putting in a track box vs tuttle is that you can't angle the box forward like with the tuttle box so the foil's fuselage is parallel to the top of the board. I'm going to have to create a ~1/4" wedge shim so the foil will be angled right. Kind of a bummer, but should work. Had I thought about this more ahead of time I could have built that angle into my tuttle to track box adapter, oh well! I kind of missed this because I was used to the Lift foil, which had the angle built into it already. I haven't ridden the GoFoil yet, so I wasn't as aware that it's not pre-angled for you.
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Deck side cassette is sanded down. I was going to glass this side first, then if I mess up it's under the pad! :-[
I think I'm going with 3 layers of 6oz carbon. First one starting out 1" larger than the cassette, and moving out an inch in all directions on each next layer. Then one final light fiberglass layer, so I don't have to sand the carbon, and to help with any pinholes.
On the bottom I guess I'll do something similar depending on how the top comes out.
Nearing the end here!
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You'll see pictures of big carbon patches on the bottom of the boards but I am realizing this is backwards.
The majority of the Stress is VERTICAL like a column punching Upward into the Deck. 'If' your box is secured to the foam then the bulk of stress should be dissipated or managed by the carbon on the TOP deck, NOT the bottom.
Take a look at my failure and Sam Pae's failed Tuttle boxes. The box just pushed through the upper deck. A static diagram will show the force is applied slightly forward of the mast which is also why my box punched upward on the front bolt and bent forward pulling down and through the deck with the rear bolt.
PS: Sam fixed his box with Gorilla Glue (not that it matters now)
His fix here:
https://www.facebook.com/photo.php?fbid=10211306341677472&set=pcb.10211306387798625&type=3&theater
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Wow! That is great info, thanks! I will add one layer of carbon to the top deck and take one out of the bottom.
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My layout is going to look something like this... the outlines would be the edges of each layer of carbon/glass. I will likely cut the corners off though and make more of a diamond shape to avoid making a stress point
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Roger that Beasho!
Always reinforce the deck. Carbon / Glass patch
(https://i.imgur.com/kroYPjQl.jpg)
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I'm about to vacuum bag on my top laminates on, what's the max safe vacuum for an all fiberglass/wood sandwich board with an EPS core? I was thinking around 5-10 inHg? I don't want to crush the thing! And YES vent plug is removed! :P
I'm a bit leery because the PVC block is much less compressible than the EPS... so I don't want the EPS to shrink and pull away from the PVC part!
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Are you using a full bag around the entire board or just sealing bag material to the deck? If you do the latter there is no chance of squashing the board.
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Full bag, it's like a zip lock type so no choice. I've dialed in ~7 inHG but I haven't started yet.
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You will be fine at 10inHG
(https://i.imgur.com/fghe5xml.jpg)
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Excellent timing, I just stuck it in the bag at 7inHG, so upped it to 10... I did notice that more extra epoxy was coming out from under the Mylar after that too.
What I did was mask off the area to be glassed and sanded each layer I was putting in separately, each one masked off, so kind of a stepping surface to match the plys. Then cut out a Mylar (14mil) to the exact shape of the patch and then did my layup on the Mylar in reverse order, from top layer to bottom... 1.4oz glass, 5.7oz carbon spread tow, 5.8oz carbon twill x 3.. each reducing in size as they went. I wetted out the board and the whole laminate well and then vacuum bagged it on. With any luck, when it's done all I have to do is pull up the Mylar and the outlined tape and maybe knock down a slight tape thickness edge around the sides with a blade/scraper. Hopefully it comes out nice and pre-finished! :)
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I'm only making this side nice as practice for when I do the bottom. Obviously the top is getting covered up with a pad and so pointless to make nice.
Shoot, I noticed from my pictures in the post that I didn't put a breather cloth over the vent plug hole so the inner board can equalize. Just went back and quickly did that! I guess the risk of not doing that would be having air from inside the board trying to get out... like through a pinhole under my laminate! Fixed that!
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Ok, so lessons learned on the practice side...
10inHG was a little too much vacuum. The board did compress around the cassette and make a slight bump around it like I was wanting to avoid. Nothing huge but visible from a side view. I think 5-7inHG max next time.
Don't leave the vacuum feed in the middle of the laminate when bagging, duh! It left a dimple in my layup, again, no biggie, just visual Just me being lazy and not moving it
Don't over squeegee the laminate, even with the Mylar over it. I was squeegeeing like crazy to try and get out excess epoxy (I felt like not enough was coming out, in reality the layup wasn't that epoxy rich). What I did, which I know better from past experience, is introduce tiny air bubbles between the glass and carbon. Just a visual thing really, the surface is still sealed fine. I also sealed my sanded area with cabosil thickened epoxy and let it tack up before doing my layup, so pinhole chance is very low despite how it might look. Even after putting in the cassette the surface was already sealed, so really I have double countermeasures for pinhole possibility.
That's about it, everything else came out great. The edge was just how I expected, a slight lip I hit with the edge of a single edge razorblade and it was basically flush without looking bad.
I'll be applying what I learned to the bottom layup, which will be visible.
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Boy, the more I sit here and think about this, I'm not sure this is going to be the best way to do things.
For one, I should not be bagging the whole board, I should have gotten sealing tape and just vacuumed the surface if I wanted to vacuum bag. That would avoid the whole board compressing bit and I could use as much vacuum as I wanted then too.
Second, the bottom side is going to have the two fin boxes. That obviously isn't going to work well with the vacuum bagging scenario. It will want to suck everything down into the boxes. I'd have to cover the boxes with something like a wood insert and then risk that getting glued into the boxes.
The other option, which was actually my original plan, was to use the Mylar how I did, but put a big piece of foam rubber over the whole thing and weight it down massively, ie poor mans vacuum bag.
There's always the option of going no vacuum or Mylar and doing a hot coat as finish. I just don't want to sand/finish anything, but still want a nice even smooth/gloss finish.
Going to have to think about this one for a while....
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Supper: You are clearly a perfectionist. I can't come close to your ability with Epoxy, bagging and beauty. eDubz may only be qualified to comment.
However you started this thread on April 14th. 20 days later my Tuttle box blew out. 5 days later I fixed it and have surf 85+ waves over 6 sessions including the best and longest Foil wave of my life from the 3rd peak at Mavericks on a 10+ foot screamer 600+ yards through the rocks to the inner lagoon. It is now a month later.
I worked for Tom Siebel who loved to say "We have a bias for action. The perfect idea that takes too long is worthless compared to an 80% baked idea that is implemented immediately." Granted this is a harsh perspective from an angry but successful business leader.
The first time my Tuttle box blew out I concluded that Box Failure will become a regular occurrence and it has. I had 2 professional installations. The first one cracked, I fixed it, then a 10 foot wave blew it out. I fixed it and surfed it for 500+ waves. This second box just melted away after 7 sessions. I fixed it.
If you are making the board beautiful for artistic purposes or for resale that is one thing. Otherwise the sport is moving so fast that this setup is already obsolete. Work quickly. Your work will hold. Laminate the bottom and start flying.
With Love - Beasho ;D
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LOL, oh man, you're so right! I can get to finicky about doing things just perfect sometimes. I guess part of it is my last two failures were so huge, first I broke my foil, then I lost another out outright! I'm feeling a little gun shy about throwing something together without really knowing what I'm doing. Well, on the bright side, it's almost over, you won't have to suffer through it for much longer ;)
Thanks for the reality check beasho, I needed that perspective. 8)
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I never bagged a full board for tuttle box or tracks. I would imagine by removing the Vent plug the vacuum was pulling air from inside the board. Tacky tape and seal around the box only in the bottom.
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If you are making the board beautiful for artistic purposes or for resale that is one thing. Otherwise the sport is moving so fast that this setup is already obsolete. Work quickly. Your work will hold. Laminate the bottom and start flying.
Reminds me of:
Confucius: "Better a diamond with a flaw than a pebble without."
:)
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I’m guilty of the same shark supper. Sometimes my projects never even get started because I want perfection and second guess myself etc. So maybe you should just knock it out and enjoy a martini like beasho did and get back on the water.
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Finally over, had to wait for some supplies to finish, now it's done.
I vacuum bagged the single surface method for the second side. I thought this would be the better way to vacuum bag. In some ways it was much better, but it really was wasn't in other big ways. I'd bag the whole board at a lower vacuum pressure had I to do it again. One tiny pin hole using the single surface way can kill the whole layup by introducing air into the layup. With a whole bag the vacuum is equalized on both sides of the layup, so pin holes don't matter as much. Hope that helps someone in the future.
I'm going foiling... 8)
Over and out.
If I'm feeling brave and have the time I'll try building a custom foil board this summer.
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Congrats sharksupper, and thank you for taking us on the journey with you, I learned a lot...mostly that I don't have the skill, patience, or proper equipment (nor space) to take on such a project. But you did an outstanding job, and your craftsmanship shines through with your completed work on the mast track inserts, and the beautiful Tuttle adaptor you're going to be installing on them.
Well done sir, well done. My hat's off to you.
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It looks like Dub is using a single surface "bag" with that ten pounds. I don't think I'd take a full bag that far. Too easy to distort the board. It's true that you can't do a single sided bag on a leaky surface. I generally test everything before I go live with epoxy. It sometimes wastes sealant and bag material, but it's better than watching bubbles push through your glass job. And a leaky single-sided job can crush a board if you forget to pull the vent plug.
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Spot on Bill. 10inHG was too much, as you said, distorted the board a bit. Wasn't terrible, and pretty much all of it relaxed during a two day post cure, but I'd stick to 5-7inHG max next time.
When I did the single surface method I got a few small air voids in places, which I poked holes on either side of and forced epoxy through. The funny thing was the vacuum pump was not cycling and no air was coming out from the laminate, so a bit perplexing. Anyway, that was only with my top, mostly for visuals, layer, the main base laminates were solid.
Very interesting learning as I go along, thanks everyone for all the tips and advice. Not just the technical board stuff but the life stuff too ;D