Author Topic: Foil Box Failure  (Read 9065 times)

jrandy

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Re: Foil Box Failure
« Reply #15 on: December 20, 2017, 08:19:48 PM »
Beasho, I like the Dremel idea. If I could only find mine...

I dropped a longboard on the end of a piece of angle iron that holds the lights on my trailer, making a L-shaped cut through the fiberglass and into the foam 1/2 inch (13mm) deep. Happened over the summer, I am just getting to this tonight as we approach Christmas.
 
I cleaned and sanded the area and made the corner of the wound just large enough to drip in the Gorilla Glue. I misted some water in the hole with a recycled spray bottle. I added a small drop of glue and another small mist of water then stirred with a toothpick. I did this a couple times. Tomorrow will be a trim and sand and first layer of glassing.
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Be safe, have fun. -J

Chilly

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Re: Foil Box Failure
« Reply #16 on: December 21, 2017, 04:27:55 AM »
Thanks for the sharing your experiment Beasho. Could Gorilla Glue be used to repair a small areas were foam is missing instead of using a mixture of Micro-Balloons and epoxy to fill in a void in the foam?

Yes - HARD STOP . . . . 100%  Much easier using Gorilla Glue than Epoxy and Micro-balloons.

There is a trick.  You need to add 'kicker'.  With Gorilla Glue this is a touch of water.  I whip it in with a Dremel.  Spray a few dustings and whip the glue until it turns lighter and aerated.  What this does is to ensure the glue cures from within and doesn't form large gaps.   

Thanks Beasho! I was worried that there may be large gaps in the Gorilla foam, but your technique of getting a good mixture should solve that.
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Beasho

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Re: Foil Box Failure
« Reply #17 on: December 23, 2017, 07:49:58 AM »
See this video for how I mix up the Gorilla Glue. 

This also has some estimates on resulting density ~ 4 lbs per cubic foot.

« Last Edit: December 23, 2017, 07:52:43 AM by Beasho »

Beasho

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Re: Foil Box Failure
« Reply #18 on: December 23, 2017, 08:04:29 AM »
Note: The cell structure of the Gorilla glue.  It was most entirely filled in.

The Great Stuff formed a solid bubble, on top, but when I cut into the foam it was uncured and still wet beneath the top coat. 

The problem with Poly glues is that while curing they insulate themselves from the moisture needed to cure the glue itself.  Whipping the water into the Gorilla glue appeared to address the problem of large voids and uncured lower layers.  Great Stuff alone would be hard to work with because it comes out already expanded where the Gorilla glue, mixed with a few sprays of water, starts out with a higher density and then expands to fill the cavities.     
« Last Edit: December 23, 2017, 08:07:04 AM by Beasho »

Beasho

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Re: Foil Box Failure
« Reply #19 on: January 02, 2018, 08:20:55 AM »
Box repaired with Gorilla Glue.

Best thing to trim the gorilla glue is a sharp knife.  In this case a constantly sharpened filet knife. 

Beasho

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Re: Foil Box Failure
« Reply #20 on: January 02, 2018, 08:23:16 AM »
Top deck installed a divinycell plug and then 5 layers of 6 oz cloth.
« Last Edit: January 02, 2018, 09:08:14 AM by Beasho »

Beasho

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Re: Foil Box Failure
« Reply #21 on: January 02, 2018, 08:40:27 AM »
2 Layers of 6 oz fiberglass followed up with 2 layers of 6 oz carbon patch.

Cutting the Tuttle hole can be a challenge.  I used the black carbon cutting discs on my Dremel.  I put blue painters tape inside the box to indicate the sides of the box and serve as a visual aid when I was getting close to the edge.  I also put a disposable Styrofoam plug into the Tuttle to prevent any epoxy drips.     
« Last Edit: January 02, 2018, 08:54:47 AM by Beasho »

Beasho

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Re: Foil Box Failure
« Reply #22 on: January 02, 2018, 09:03:05 AM »
I've been riding the repaired box for 2+ weeks now, a couple hundred waves up to 8 feet.  No signs of any stress.

The moral of the story: Mentally prepare yourself, if you get hit by a big wave, for your box to rip out.  The good news is that the repair can be less painful than you'd expect.   

PonoBill

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Re: Foil Box Failure
« Reply #23 on: January 02, 2018, 10:02:41 AM »
Nice. The big carbon patches are a fine idea.

I got a little carried away with mine. Similar board.



I'm sensing a theme here. I guess I like yellow, red and white boards.
« Last Edit: January 02, 2018, 10:04:21 AM by PonoBill »
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Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

Beasho

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Re: Foil Box Failure
« Reply #24 on: January 02, 2018, 10:42:44 AM »
Nice. The big carbon patches are a fine idea.
. . . . .
I got a little carried away with mine. Similar board.

Pono - Are you foiling yet?

Sam Pae 230# is flying around on the Maliko 200 and able to pump back to sea catching 2 waves for 1.  Haley 240# has been successfully flying on Kai foil but would have been better off learning with an array of larger foils.  I am about to pull the trigger on an Iwa and Maliko 200.

The latest theory is that the foil should be much, much more efficient than a schloggy surfboard.  Big guys rejoice.  Just get a larger foil and start flying.  Weak link might be the boxes or the mast, maybe not.   

jrandy

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Re: Foil Box Failure
« Reply #25 on: January 02, 2018, 06:23:53 PM »
Thanks for the write-up Beasho, nicely done!
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Be safe, have fun. -J

PonoBill

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Re: Foil Box Failure
« Reply #26 on: January 02, 2018, 10:42:08 PM »
My weak link is my dodgy knee. It's doing pretty well though, so I think it's time to jump in.
Ponohouse is for sale: http://www.ponohouse.com
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

blackeye

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Re: Foil Box Failure
« Reply #27 on: January 03, 2018, 11:12:46 AM »
Box repaired with Gorilla Glue.

Best thing to trim the gorilla glue is a sharp knife.  In this case a constantly sharpened filet knife.

Nice repair and successful too.

Your knife is pointing at some large stress fractures that you haven't talked about, and I see in one of your photos that you laid some glass there (Starboard side extending half way from the box to the rail). That damage must be related to the box mount failure. I am interested to see how this area holds up. 

blackeye

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Re: Foil Box Failure
« Reply #28 on: January 03, 2018, 11:29:47 AM »
A question for anyone - Are the patches over boxes and tracks simply lying on top of them and connected only by epoxy? ie I don't see any fibre connecting box to deck / bottom laminates except for this overlay. It strikes me that both epoxy and fibre are being asked to do something it they aren't really designed to do.

I suggest that boxes be mounted such that they are slightly proud on the bottom (and top for Tuttles). Then Carbon tow strands be half-looped around them with the tails ending on the opposite sides of where they contact the box. The tails could be spread out radially. This way the forces would be directly transferred to the carbon tow in tension, then to the patches and regular laminates. Variation: if proud is no good, dig into the foam so the loops can contact the boxes, then feather the foam as the tow rises to the surface. Fill the voids afterwards if that is important, then laminate.

I also suggest that masts should be designed with a "fuse" or a "breaker", much like a release on a ski binding. Either an intentional weak/brittle spot that is easily repaired or a mechanism that can be reset on the spot. This just occurred to me so no suggestions as to how to do it. It would add complexity, cost, likely weight. And would take repair work away from eDubz, which none of us want. 


PonoBill

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Re: Foil Box Failure
« Reply #29 on: January 03, 2018, 01:58:12 PM »
A question for anyone - Are the patches over boxes and tracks simply lying on top of them and connected only by epoxy? ie I don't see any fibre connecting box to deck / bottom laminates except for this overlay. It strikes me that both epoxy and fibre are being asked to do something it they aren't really designed to do.
I do two layers of carbon generally, the first is table wet and laid on loosely, razor cut in the middle, and then the mast track or box in its PVC cartridge is "buttered" with epoxy and chopped CF and pressed in, taking carbon with it along the sides. I roll the shit out of it to get the carbon flat and let it set until it's tacky, then roll it again, and add a second patch over the top and roll it to incorporate. I generally fill the slot with foam and trim the opening with a razor if I get to it while the second layer is still soft. I generally add a layer of 4oz to sand and then hot coat.

The board in this picture was a bit different because I added the Tuttle after the mast tracks were in place. I used a GoFoil pre-wrapped and layered Tuttle cut down to fit snugly between the tracks. I Gorilla Glued it in place, trimmed the top flat, and then just laid patched over the inserts. I'm counting on the well-anchored tracks to support the Tuttle. It's been well used and abused by others, so I think it's fine, but we'll see what happens with my fat ass on it and a monster foil attached.
« Last Edit: January 03, 2018, 02:04:53 PM by PonoBill »
Ponohouse is for sale: http://www.ponohouse.com
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.