# Gorilla Glue on a boat?



## jr438234606 (Apr 25, 2006)

I am trying to repair a 2x2 section of my deck that has delaminated. I drilled several 1" holes underneath the deck (rather than drilling through the top of the deck) to inspect the core. The wood is perfectly dry with no rot. There is a 1/8" gap between the core and the glass on the deck in this 2x2 section. I need to inject something in there to fill the void.

Conventional wisdom says I should inject polyester or epoxy resin. However, I am wondering if a popular urethane glue (Such as Gorilla Glue, sold everywhere in the U.S.) would work better. Here is my though process on the pros and cons:

Resin Pros:
Durable (Hard)
Waterproof
Injectable, but rather thick.

Resin Cons:
Hard to get into every nook and cranny of the delaminated areas (because it's so thick)
Very messy to work with.
Limited Pot time.
Is the substance that let go of the wood core in the first place.


Gorilla Glue Pros:
Durable.
Waterproof.
Easily injectable as it is rather thin.
Expands to fill voids.
Not particularly messy to work with.

Gorilla Glue Cons:
Requires introduction of moisture into wood core in order to activate glue.
Not quite as rigid as resin (IMHO).


The fact that the Gorilla Glue expands (foams up) to fill voids would seem like a major advantage. Anyone care to weigh in on this?

John


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## TSOJOURNER (Dec 16, 1999)

John: If it is delaminated, would injecting something into the gap leave your deck uneven?


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## TrueBlue (Oct 11, 2004)

Thankfully, my boat has solid fiberglass decks under teak. But if I was faced with the repair of a delam balsa core, West System would be my first choice.

http://www.westsystem.com/ewmag/19/Replacing_Core.html


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## jr438234606 (Apr 25, 2006)

Surf: No, the deck is not mishaped in any way. The glass on top is still quite rigid. When you walk on it, the glass flexes and you can just hear it "tap" the core beneath. When you step off of it, it bounces right back. I think Gorilla Glue would expand to fill the void without pushing up on the glass or changing the shape at all.


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## sailingfool (Apr 17, 2000)

Gorilla glue is great stuff and I recommend heartly for bonding wood, and I've used it on many interior components. For rebonding the deck I'd recommend West Sytem epoxy, stiffened with the silica filler where necessary.

To me the big negative with the Gorilla Glue would be the risk that its expansion may result in a hump in the deck surface. A second question would be if it has the hardness of the epoxy and the ability to bond to glass.

The West stuff is very easy to work with, will adhere like no tomorrow (so be careful, especially plan for dripping) and the silica will allow you to make it as thick as you want. 

I believe West has some literature for planning deck repairs. I'd inject straight epoxy via their syringes, then compress the area, say with a jack and weights. You can use the thickened stuff to fill any voids and your drill holes.

This stuff is not too expensive (in boat $$), you might want to practice with some sample peices.

Good luck.


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## sailingdog (Mar 19, 2006)

The other problem is that Gorilla Glue does expand... and the expansion could possibly lead to further delamination or voids. I'd stick with West System or System Three epoxies for deck repairs. They're proven and well known.

If the deck core is dry, it sounds like your boat had a lamination fault to begin with, and that this is not a delamination problem, but a bonding failure problem.* My real question is why is there a 1/8" void in between what should be two layers of laminate.* It might be worth doing a bit more investigation to see why there is such a gap.


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## TrueBlue (Oct 11, 2004)

Based upon the initial description, the 1/8" space exists between the balsa core and the bottom sheet of FRP, as observed through the holes drilled from the interior headliner. I would then suspect that the bottm FRP had deflected away from the balsa and may just need to be compressed from below after injecting West System epoxy. The stuff is not expensive if you're just dealing with a 2' x 2' area.


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## jr438234606 (Apr 25, 2006)

Sailingdog: I think you have a good point. When I look at the glass that has "delaminated" from the wood, I'm inclined to think it was never attached to the wood in the first place. It's very smooth and clean. It may have been a void present since manufacturing. Perhaps the builder just didn't get enough resin in there and it never bonded at all... perhaps I'm the only owner of this particular boat that has noticed or cared to fix it.

I guess I'll leave the experimentation to someone else and use the resin.

Thanks all.


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## sailingdog (Mar 19, 2006)

If the "delaminated wood" is clean and smooth...it is definitely a lamination bonding failure from when it was built, rather than delamination. I'd raise the interior of the deck in that location after injecting the epoxy... it'll make for a lighter and stronger repair IMHO.


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## TSOJOURNER (Dec 16, 1999)

You could build a "T" out of 2x4's cut to the height you know will compress the lower side to the stop. Inject in the West System and place a weight on top. Then stand up the T. This will allow the two layers to bond. (Just an idea but it might work).


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## pigslo (Nov 22, 2004)

Here is one solution. The rot doctor resin has a thinner viscosity and the result is it will flow into the cracks better.

www.cncphotoalbum.com/doityourself/rotrepair/rotrepair2.htm

pigslo


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## sailingdog (Mar 19, 2006)

I would support the base of the T with as large a sheet of 1/2" plywood as you can fit...to spread the load out. No point in doing one repair, and causing damage to be repaired in the process.


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## TSOJOURNER (Dec 16, 1999)

I think this would work also,drill small relief holes on the border of delaminated area,and one hole in center of area.Mix epox and apply with a pressureized gun.this will fill the area with epoxy and you know its there because it should run out of the perimeter holes,clamp as the fromer posts mention and wait for it to cure sand the runout which you have tape on after it starts to flow out,and paint.I never tryied this but it seems like it should work.Good luck and keep us posted on the repair.


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## jr438234606 (Apr 25, 2006)

*Update*

Update: Call me crazy, but after giving it much thought, I changed my mind AGAIN and decided to try the repair with Gorilla Glue after all. I can honestly say I am VERY pleased with the results. The more I thought about trying to make the repair with epoxy resin, the more I was dissuaded from it. (Visions of dozens, upon dozens of tiny syringes full of epoxy-- groan.)

As I mentioned in my previous post, I was not suffering from delamination-- but rather a VOID probably present since construction. I drilled four 1" holes underneath the 2x2 problem area and discovered a void between the top deck glass and the core which varied in height from 1/8" to 1/4". This measured out to be at *least *72 cubic inches of space that had to be filled. This would have taken nearly 1/3 gallon of epoxy.

Using a cork, I first injected a modest amount of water followed by a generous amount of the Gorilla Glue into each of the four holes. After a few minutes, the glue started reacting and expanding. It started quickly filling in the entire cavity to the extent that it began forcing the residual water out. (It actually started squirting out in a stream!) It was obviously building up pressure in the cavity. For a moment, I thought it may actually cause the void to bulge up, making matters worse. But, this was not the case. Apparently, the expanding glue has the unique property of remaining fluid while seeking out all available space. When the space is filled, it doesn't keep expanding. Instead, it simply bonds and dries in that shape. This makes sense, because if it expanded uncontrollably, how would it ever bond two pieces of wood together without always forcing them apart?

Anyway, after 4 hours I walked around on the deck and was pleased to discover my problem area was rock-solid. Using only four little holes, the glue expanded and filled in every nook and cranny. If my problem had been a delamination with some rot, and with very little space to fill, I would have probably gone with the resin. But for filling in a void where the deck is structurally sound and just has an "air pocket", I would definitely use the glue again.


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## TrueBlue (Oct 11, 2004)

Glad to hear of your success johnr, now get out there and sail.


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