Standup Zone Forum
General => The Shape Shack => Topic started by: sflinux on January 18, 2022, 05:12:03 PM
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I have been using this technique to make gorilla glue foam:
https://www.youtube.com/watch?v=ggekRdoQJNE (https://www.youtube.com/watch?v=ggekRdoQJNE)
I like that the gorilla glue cures faster and has smaller bubbles.
But sometimes, it expands more than I would like.
I recently came across this instructable, where Andy Callaway mixes gorilla glue with corn starch:
https://www.instructables.com/Gorilla-Glue-Foam/ (https://www.instructables.com/Gorilla-Glue-Foam/)
This gives a rigid product that is fairly easy to spread, and dries with a very rigid surface.
I also experimented with premixing the corn starch with water, or vinegar, but that lead to an inferior product. I definitely recommend just adding corn starch neat. I would say the benefit of this technique is it doesn't foam as much as the above (vinegar/baking soda) technique, which could be useful for thin patches (< 1 cm) where you don't want to waste a lot of epoxy & q cell, which can be a little runny. The jury is out on which is lighter.
I was trying to make a product similar to this foam putty:
https://www.amazon.com/Horizon-Hobby-Woodland-Scenics-WOOST1447/dp/B0006NARV8/ref=asc_df_B0006NARV8/ (https://www.amazon.com/Horizon-Hobby-Woodland-Scenics-WOOST1447/dp/B0006NARV8/ref=asc_df_B0006NARV8/)
Inspired by this repair video:
https://www.youtube.com/watch?v=lsQp-Z2mKMY (https://www.youtube.com/watch?v=lsQp-Z2mKMY)
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I have seen various techniques but never the corn starch! If you do add water you only need 1 or 2 drops.
A friend of mine is a boat builder and he was talking about a rudder somebody built. They had glued slabs of wood together with PU glue, same as gorilla glue. Then shaped it.They were going to glass it and he said that's a really bad idea. He was taught epoxy dosnt like to stick to PU glue. I told him plenty of people do it on surfboards.
Has anybody noticed epoxy not stick to a PU glue line?
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I've had the epoxy separate from EPS foam, but it won't come off the PU glue. Here's a board I pieced together with Gorilla Glue and scrap foam. Even spliced the stringer together with GG. The wood tail block is set with GG. The fin box is set with GG. It's been at least 5 years and no delamination anywhere on the board.
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I will call this a "How to Faster Cure Gorilla Glue"
I saw that original video and said Phoohooheee. Too Complicated.
So I just add a few sprits of Water to the Gorilla glue and whip it until it turns white. This cure fast, fills voids, has a solid internal consistency and sticks to everything. Density is ~ 4 lbs / ft^3
I have repaired multiple tuttle box failures, broken boards . . . using this system and have found that Gorilla glue, unlike epoxy, actually does stick to everything such as divinycell.
I have laminated over this and NOT had failures put to pretty extreme tests.
https://www.youtube.com/watch?v=UgZ3A3igBbY
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Here is a link to one of my box repairs showing the Gorilla Glue Fill layer:
https://www.standupzone.com/forum/index.php/topic,35287.msg406243.html#msg406243
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I did argue a bit with him. Obviously its fine. Just weird they would teach them that. Maybe he just got it wrong. Did a few google searches and lots of evidence to say epoxy bonds well to PU.
I bought some additive for epoxy that makes it foam ages ago. Used it once to glue wood to a foam core. It worked. No idea if it was better.
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So this stuff would be good to glue in a foilbox?.
It is a big rectangle of high densityPVC foam,will nest in EPS board.
I want something that will stick,fill voids without soaking into the EPS and not expand with too much force.
I will clamp the foil box to the board but it could still deform or lean...
Starched or neat? :)
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Yes. Just a moist paper towel wiped on the surfaces before you apply the glue. It does expand a little. The wetter you get it, the more it expands. You won't get the exotherm as you do setting fin boxes with epoxy and larger gaps. When you have to big of a gap between the foam and fin box, the addition volume of epoxy will get hot enough to melt the foam away from the fin box or leash pug. GG won't do that. It will actually fill the voids with a foam stronger than the high density foam you're setting it in.
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Paper towel and regular gold Gorilla glue will NOT fill voids correctly. You need to whip it up. See this video again.
Gorilla glue that hasn't been cured with moisture Inside and Out will create its own bubble inside the matrix. If you test it in a dixie cup and then CUT the foam you will see what I am talking about.
https://www.youtube.com/watch?v=UgZ3A3igBbY
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Here is how it all went together using Purple XPS foam, in EPS with a Tuttle Box, Gorilla glue WHIPPED White.
Layered with 2 X 6 oz of Fiberglass and then 2 X 6 oz of Carbon TOP and Bottom.
This board was built with Dual Tracks sitting on top of beer cooler foam. The boxes melted down in 5 sessions.
This Tuttle Re-Installation has lasted 2 1/2 years.
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I've done the tour starting with Gorilla glue and them moving to all types and brands of pour foam. I'm back to Gorilla Glue-when whipped up it is a consistent foam structure(as shown above) and sticks to most anything.
Question-does it absorb water?
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Ok,thx guys.
I have ordered some Gorilla Glue.
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Question-does it absorb water?
Yes, but so does pour-foam. Treat it just like bare EPS and you're good.
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Question-does it absorb water?
Yes, but so does pour-foam. Treat it just like bare EPS and you're good.
And i was sure PVC foams were mostly waterproof,being closed cell.At least a lot more water resistant than EPS...
So they are not?, i am right now using Foam-it 5 pour foam to fill some cavities,it will be glassed over but i thought the foam would be a water barrier too.
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PVC is a closed-cell foam, standard EPS is not, XPS is somewhere in between. Two-part pour foam is a closed-cell and the better versions have strength somewhere between XPS and PVC. Gorilla glue that's been whipped with water is stronger than two-part foam and sticks better. Two-part foam eventually breaks down with continued pressure and eventually loses its water resistance even before it gets weak. I've used gallons of two-part to make body-formed seats for race cars. Mix well, pour into plastic bags, tape it to the seat base, and sit down. Don't pour in too much or you'll have it in your hair (not that I'd know).
I have an old hand mixer with a modified single beater for mixing epoxies, foams, and gorilla glue. I clean the beater by holding it in an empty bucket and switching it to high, then wipe off the tiny residual mess with a rag. Power mixing changes the entire game. Hand-mixed gorilla glue has voids with dense areas of poorly cured glue. Power mixed it's as consistent as commercial PVC. I haven't tried cornmeal though I've tried micro balloons to try to get a lighter filler. That works though it's hard to get enough in the mix to make it worth the effort when the glue is doing its best to turn to foam before you can finish.
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Dremel tool, opened up paper clip = tiny batch mixer.
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PVC is a closed-cell foam, standard EPS is not, XPS is somewhere in between. Two-part pour foam is a closed-cell and the better versions have strength somewhere between XPS and PVC. Gorilla glue that's been whipped with water is stronger than two-part foam and sticks better. Two-part foam eventually breaks down with continued pressure and eventually loses its water resistance even before it gets weak. I've used gallons of two-part to make body-formed seats for race cars. Mix well, pour into plastic bags, tape it to the seat base, and sit down. Don't pour in too much or you'll have it in your hair (not that I'd know).
I have an old hand mixer with a modified single beater for mixing epoxies, foams, and gorilla glue. I clean the beater by holding it in an empty bucket and switching it to high, then wipe off the tiny residual mess with a rag. Power mixing changes the entire game. Hand-mixed gorilla glue has voids with dense areas of poorly cured glue. Power mixed it's as consistent as commercial PVC. I haven't tried cornmeal though I've tried micro balloons to try to get a lighter filler. That works though it's hard to get enough in the mix to make it worth the effort when the glue is doing its best to turn to foam before you can finish.
Bill-thanks for the summary there bud. Good to hear this stuff based on experience.
Actually thanks everyone for this super informative subject.
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Dremel tool, opened up paper clip = tiny batch mixer.
Perfect for small jobs ,thx.
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Here is a small rail ding on a King's that was made much worse by attempting the repair with polyester resin. As you can see, the polyester resin created an ugly cavity.
Ordinarily I would cut the old glass out completely and replace the foam with EPS. But, in this case, to avoid the hassle of dealing with the Kevlar vector-net, I simply filled the void with GG and allowed it to expand leaving a small escape slit in the tape. The expanding GG actually pushed the surrounding glass back to it's original shape (more or less). A little epoxy and some 6oz glass and Bob's your uncle...
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Beasho thanks for posting. I should have mentioned your video technique as well because that is the one that got me interested in gorilla glue to begin with. Your technique is the best for gorilla glue repairs.
Bean, thanks for posting, excellent description of its application. I used a similar technique for a disturbed fin box for a board that had fallen off roof racks while driving. I drilled 1/4" holes around the disturbed parts of the fin box, then filled the cavity with gorilla glue foam. Then covered up the top with glass like your repair. I also used this technique for a snapped board.
This corn starch method has me interested in repair areas like deck standing areas, as the outer skin is really firm. I will have to cut the outer skin to see how the firmness of the inside compares to the inside of standard gorilla glue foam.
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(http://)So tomorrow i will bed in the foil box with Gorilla Glue.
It is a big surface but a very tight fit.
I am not sure how to go about it,i have played with the water&dremel method and it cures fine but rises rather quick.
What is the best way to apply it in this (foil box) situation?
-Do i mix a batch with water and brush it on so it will cover the bottom&sides and then push the box in?.My worry is that i will not be quick enough before it starts to get gooey.
-If i just pour it covering the bottom as much as possible will it expand and come out the sides by itself?.Here i fear it pooling in places and leaving others bare.
-Another option would be to brush it neat and thin all over the cavity, mist-spray with water and put the box in.
Thx for any tips, i have not found vids of people doing this.
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Another pic
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It looks like you have a good close fit. I have done similar job putting boxes back in. I buttered up both surfaces using a paint brush, then hit it with a mist sprayer and installed it. You need to have a plan to clamp it in place, the foaming will move things around. Figure out you clamping system before you open the glue bottle.
I did my repair a little different see photos, but all set in gorilla glue , neat not foamed but misted on insertion.
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Thx Bean, sounds like a good plan.
I will cook up something to clamp the box securely down quickly ,great tip.
Some great ideas in your pics, i like the tubes to connect the box loads to the deck ,and the fully wrapped boxes.Looks bomber.
BTW my fit was so tight that i had a moment of panic, i test inserted the box and it went in nicely but totally refused to come out :).A thin nail file run round the edges saved me...
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It looks like you have a good close fit. I have done similar job putting boxes back in. I buttered up both surfaces using a paint brush, then hit it with a mist sprayer and installed it. You need to have a plan to clamp it in place, the foaming will move things around. Figure out you clamping system before you open the glue bottle.
I did my repair a little different see photos, but all set in gorilla glue , neat not foamed but misted on insertion.
In my previous post i meant thanks Finbox,sorry.
Got my forum names confused!!
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On the last board I repaired - I did a DW wrap of carbon on the box with a foam inner. I skipped the high density foam, left the top skin in tact and epoxied to the bottom of the deck, with a fiberglass layer for filler. Then filled the gaps on the side with gorilla glue - injected with a syringe, I filled the box opening with a waterproof sheet foam and glassed over the boxes. Then routed the box back open. So the foil mount bolts clamp the carbon skin layer on the bottom of the board.
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That is perfect.
I almost went for the DW method,my favorite!!...but i chickened out thinking this would be less work and easier for a newbie.
Plus the board i am butchering has rocker&Vee bottom in the foil area so i thought the flat PVC box would be a help in getting things lined up.
I did dig trenches in the EPS all the way to the deck and filled them with pour foam PVC so there is some added support.
Box is in now, will let the Gorilla Glue cure a few hours before removing clamps.
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Wow, nice work you guys. Yeah, the mixed Gorilla glue goes off faster than two-part, which is fast enough. I don't use it for simple gluing, more for filling or installing something when there's some big gaps and I can slam things together quickly while the glue is trying its best to fuck up everything. If you don't have your clamping stuff ready before you mix the glue it's already too late.
I did try to mold it one time in a simple open mold that should have released almost anything with lots of mold release. I couldn't get it out even after the mold finally broke, so I don't recommend that.
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Yes,sticks like crazy.
I did a test on divinycell, smooth shiny sides,no sanding.
Thin layer,spray and press.
The pieces only came apart by tearing the divinycell.
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That is perfect.
I almost went for the DW method,my favorite!!...but i chickened out thinking this would be less work and easier for a newbie.
Plus the board i am butchering has rocker&Vee bottom in the foil area so i thought the flat PVC box would be a help in getting things lined up.
I did dig trenches in the EPS all the way to the deck and filled them with pour foam PVC so there is some added support.
Box is in now, will let the Gorilla Glue cure a few hours before removing clamps.
[/quote
What is the DW method? I asked him but no response.
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What is the DW method? I asked him but no response.
As i remember it:
He cut a divinicell rectangle.Same section as the US box and long enough to reach trough the deck.
This was vacuum bagged to the us box with a carbon wrap (i think 1 layer 6oz?) ,so you ended up with two "tall" us boxes.Rout the bottom,insert each box in its route with epoxy so top was glued to deck laminate.Then laminate bottom reinforcement patches.
So carbon wrapped boxes were "connecting" bottom and deck laminate.I gess the top laminate was reinforced too,not sure.
He had a webpage but i cannot find it anymore,he has stopped making boards.
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Some I'm building now with Chinook Strong Boxes
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I grabbed this off the website before it went MIA.
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On the ones I made I used 3 layers of 5.7oz carbon all at 0-90 orientation with an EPS core. I did not have enough on hand to do a 45 -45 ply.
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I grabbed this off the website before it went MIA.
Great,thx!.
We should pester DW until he makes a looong vid of a complete foil board build.
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Maybe if he has stopped making boards and shut down his website he dosnt want to be pestered? Maybe something is going on his life?
Surely he has posted enough to know how he makes his boards.
Do your own research and experiments. Thats probably how he learnt.
Sorry having a "no filter day"!
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Great,thx!.
We should pester DW until he makes a looong vid of a complete foil board build.
plus one to that!
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(http://)So tomorrow i will bed in the foil box with Gorilla Glue.
It is a big surface but a very tight fit.
I am not sure how to go about it,i have played with the water&dremel method and it cures fine but rises rather quick.
What is the best way to apply it in this (foil box) situation?
-Do i mix a batch with water and brush it on so it will cover the bottom&sides and then push the box in?.My worry is that i will not be quick enough before it starts to get gooey.
-If i just pour it covering the bottom as much as possible will it expand and come out the sides by itself?.Here i fear it pooling in places and leaving others bare.
-Another option would be to brush it neat and thin all over the cavity, mist-spray with water and put the box in.
Thx for any tips, i have not found vids of people doing this.
https://www.youtube.com/watch?v=1pIipnNehic (https://www.youtube.com/watch?v=1pIipnNehic)
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Paper towel and regular gold Gorilla glue will NOT fill voids correctly. You need to whip it up. See this video again.
Gorilla glue that hasn't been cured with moisture Inside and Out will create its own bubble inside the matrix. If you test it in a dixie cup and then CUT the foam you will see what I am talking about.
https://www.youtube.com/watch?v=UgZ3A3igBbY
After many attempts with gorilla glue, I am now of the opinion, that the more water you add to gorilla glue, the softer the foam. Initially, I was attracted to the stiffness of corn starch/gorilla glue. But in hindsight, I see it was because I was adding less water. I was ok with adding less water because I was assuming the gorilla was extracting water from the corn starch. I was initially hesitant that gorilla glue would set with a drop or two of water. But if you use Beasho's whipping technique, it gives a very firm foam with minimal voids. After playing with corn starch, I believe gorilla glue without corn starch is a superior foam, especially for marine applications.
I wanted to ask what tools are recommended for cutting excess gorilla glue. In the above video, it looks like a japanese pull saw.
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Couple of things, as Pono said, don't ship FF or glueing, whip to make foam.
And yes, we are glueing to foam, it'll tear eventually. The Dwight method ties the boxes to the deck. This is key. If you use those 2" tray inserts either glass around them or better, cut through the deck and put in an HD or pour foam pillar to connect the front and rearto the deck.
Futures boxes need to be ground down before install IMHO. If you install with glass over the ridge and sand them down, they leak. I've seen this a few times.
Glue to foam will only go so far. Secure to the composite skin. The strength is in making the box/I-beam.
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Couple of things, as Pono said, don't ship FF or glueing, whip to make foam.
And yes, we are glueing to foam, it'll tear eventually. The Dwight method ties the boxes to the deck. This is key. If you use those 2" tray inserts either glass around them or better, cut through the deck and put in an HD or pour foam pillar to connect the front and rearto the deck.
Futures boxes need to be ground down before install IMHO. If you install with glass over the ridge and sand them down, they leak. I've seen this a few times.
Glue to foam will only go so far. Secure to the composite skin. The strength is in making the box/I-beam.
+1
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I had an EPS board I built with chinook box pillars(bottom to deck) that developed some track issues with water geting in around the track. I decided to preserve the laminate on the bottom, cut through the deck and excevate the pillars and surrounding EPS.
THen i glued the pillars back onto the bottom laminate and re-cored with 2 part PU pour foam in 4lb density then re-laminated the deck.
3 Weeks later i noticed significant movemet in the track area. i opened the board up and the PU foam was all compromised. It was all almost dust.
Takeaways:
Pillar construction isn't perfect - the chinook box bond to the bottom laminate is definately a weak point. The foil sandwiching the laminate with the box helps but isn't perfect. Some other HD PVC foam is needed to distribute the load to the bottom laminate. The top of the box isn't as stressed so i don't think its as much of an issue.
PU foam is trash - Impact, tension, movement are the achiles heel. Floatation only - not structural. Probably better as glue between 2 pieces of better foamthan what i used it for.
Pro Set makes a 2 part Epoxy foam - I'd love to play with this to see how it holds up!
My latest board (prone) was cut from a solid divinycell blank. 3" slab of 3lb density. Available from aircraftspruce.com - I still did pillars - Its a BEAST i treat it like garbage. It doesn't care.
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This is how the finbox was installed in an old Fanatic Goya Windsurf waveboard i was converting.
There was carbon over and under the box, in the pic the box is at the thinnest part of the board (i cut off a bit of tail) so it almost touches the deck lam,but it is not connected to deck.
The mastbox was built pretty much the same.
It looked pretty bomber.
So i placed some glass and innegra under the foilboxes when i installed them ,if it moves i guess it will have to move the whole bottom lam.
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Don't sink, that's good but the thing to watch for is a separation of the over later from the under layer. That's where those leak. It's because we have to pierce those skins. Chinooks too, they leak at the edge as was said.
East, Thanks for this intel man.
I have wondered about bracing at the bottom particularly. I'm just about to install these pillars and now you post this!? Haha.
I want to keep the weight down. What about a 1/2" or 1" thick plate around the boxes at the bottom, just to stabilize the bottom. Maybe a good compromise?
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DontSink that windsurfing board cutaway is FANTASTIC! That raidused carbon connecting bottom to the box! Really want some windsurfing laminators making my next prone board! Nobody in the foil game is doing anything like this!
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DontSink that windsurfing board cutaway is FANTASTIC! That raidused carbon connecting bottom to the box! Really want some windsurfing laminators making my next prone board! Nobody in the foil game is doing anything like this!
Yeah, that was my reaction too.
I removed the mast and fin boxes and strap inserts to save weight and i was flipping out on how well this thing was made.
And this is a 2002 board, bought for 80€ today...
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I wouldn't say nobody. Jimmy Lewis pioneered a lot of the bulletproof windsurfing construction designs. He's still making boards, still doing custom foil boards, but you pretty much need to come to Maui and plead your case before he'll consider doing something for you. Fortunately, his production boards have most of his tricks embedded and nobody, and I mean nobody has closer control and a better relationship with his Asian production than Jimmy. And yes, I'm including Sven at Starboard who actually lives in Thailand, across a little lake from his production facility.
And then there's Mark Raaphorst, who builds about one board a week, with sublime craftsmanship, technique, advanced materials, and deep knowledge of both construction and what shape refinements are necessary to make a board do what you want it to do. Mark is an ace at surf foiling, downwind foiling, and winging. If you want one of his boards you pay your deposit and get in line. Fortunately you don't spec out your board when you make the deposit because what you want will change before you get to the front of the line--a little more than a year later. But hey, it's worth the wait. I wouldn't sell my Flying Dutchman wing board for love or money. If you do this take full advantage of Mark's knowledge, Have a long conversation with him about what you think you want and let him guide you.
Every so often I have this conversation with Mark. I literally had it again today:
"Hey Bill, I want to get my name out there a little more, make sure people know what I'm doing."
"Are you going to do production in Asia, or ramp up Junglewerks with some more folks building boards?"
"No."
"So what's the plan, push the waiting line out to two years".
"No."
"Then what the fuck are we talking for?"
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I recently came across this video of where Jimmy Lewis shows off the design idea of his sandwich contruction:
https://www.youtube.com/watch?v=1aLI-QIfnjU (https://www.youtube.com/watch?v=1aLI-QIfnjU)
I like the idea of a surfboard shell being able to support a load.
I suspect the PSH bamboo did not have a layer of fiberglass under the bamboo.
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I haven't been up to Jimmy's shop in years, I have to change that. I love watching him work. He does precise work with such an economy of effort that it's like watching a conjurer. I've done enough similar things to know how hard it is to pull that off and to realize I'll never reach that level of expertise. I measure everything five times and then fuck it up. Jimmy measures once and nails whatever he's doing with micrometer perfection. Freaks me out.
His foil boards are all full sandwich construction, with deck-to-deck carbon-reinforced PVC for the tracks. the flying dutchman boards use the same level of full sandwich construction and reinforcement.
I suspect some of the generally available production boards do the same, but I don't know for sure. There are other semi-production manufacturers like Dave Daum at King's who I have visited and watched their work who do the same level of engineered construction to produce boards that will stand up to long use.
It's worthwhile knowing what you're buying. There's a difference.
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my bubbles always come out too big...am i not whipping it well enough or too much h20?
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Probably too much water. Some folks add some neutral filler to mellow out the reaction. the only problem is that it generally makes the foam less resilient. No foam I know of, other than PVC, lasts very long. They all break down mechanically with repeated stress. PU foam is kind of somewhere between two-part foam and PVC.
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The two part foam i have used is sold as urethane foam, when cured it looks just like any PU foam.Comes in different densities.Pretty nice to work with.
https://www.smooth-on.com/product-line/foam-it/
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Pro-set makes a 2 part epoxy foam which I imagine is better than PU foam in the same way that epoxy resin is better than PU. If I had a board build on the horizon that’s what I’d be buying and testing.
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My latest version of the "Dwight Box" pillars. Based on a compromise between full HD foam and nothing I've put 2 struts between the pillars on the bottom and one in the middle on the top. Just a bit more stabilization. My year old wing board is pretty solid so far but there are 3 layers of 6oz carbon and a layer of 6oz glass over the boxes. Basically a carbon plate.
I am going to scuff up the top of my boxes with some 36 grit to help adhesion to the skin based on this thread. And yes, I'm setting the boxes with Gorilla Glue.
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Forgot pics!
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https://shop.hp-textiles.com/shop/en/advanced_search_result.php?keywords=Foaming&inc_subcat=1
Cant remember if I mentioned it but I used this for putting in a fin box. I also used it to vac bag the PVC onto the foam blank.
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https://shop.hp-textiles.com/shop/en/advanced_search_result.php?keywords=Foaming&inc_subcat=1
Cant remember if I mentioned it but I used this for putting in a fin box. I also used it to vac bag the PVC onto the foam blank.
I buy there too :)
How much did the mix increase in volume vs straight epoxy?.
Did you get even,small bubbles easily with no big voids?.