Repairing soft decks with Gorilla Glue?

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Bigfish

Senior Member
Joined
Jan 25, 2013
Messages
297
Location
USA
Vessel Name
My Lady
Vessel Make
Formosa 42 Double Cabin
Anybody tried this? I've got a few soft spots on my 42' Formosa Trawler and a guy told me he tried drilling a bunch of holes in his soft spots, not all the way through, out to where the good wood started. Then he filled them with the Original Gorilla Glue that foams and expands. Said everything feels perfectly solid now!

I was looking at a product called CPES that I was going to use but it's spendy. I just tried thinning some West system Epoxy with 15% Acetone and it seemed to do a great job but not sure how deep it went, or even if that makes a difference after all the rot is out.

What say you? Thanks folks!
 
The only way to properly repair a soft core is to cut out the bad section and replace the rotted wood with new wood and then add the fiberglass over and under it like the original construction.

Unfortunately, this is not a problem that short-cuts like CPES or injected glues will fix properly. It will just be a matter of time before the rotting process continues and in the end you'll end up with a bigger problem to fix than you have now.

This is not just me talking. This subject has come up countless times on the Grand Banks owners forum, and the consensus of the extremely experienced folks there, some of them ex-yard owners and professional shipwrights, who have dealt with this problem on both wood and glass GBs is that you either do it right or you get to do it over and over until you do do it right.

If you are not going to keep the boat all that long, the best approach may simply be to ignore it and let the next owner deal with it, although when you sell the boat you may have to reduce the price sufficiently to have the problem taken care of as part of the sales agreement. Or get it fixed at your own expense to avoid dropping the price.

But if you anticipate keeping the boat for a bunch of years, the only real solution is to bite the bullet and do the repair properly or have it done properly.
 
Thanks Marin...

I'm probably going to be selling the boat soon. I've read all the gory details about how to do it correctly and I'm afraid it would take me forever to do it and I'm having to sell the boat because I unexpectedly lost some substantial royalty checks I was expecting for another 3 years, so I can't afford what I'm sure would be a substantial chunk to fix the 4 or 5 small spots.

Thanks for taking the time to respond.
 
I wasn't going to comment earlier, but Marin is making common sense.
 
Gorilla glue swells up when it's wet (in my experience). Sounds like a good way to make things even worse...
 
Look up Smiths penetrating epoxy.
This stuff will do exactly what your talking abut doing.
 
CPES is designed to penetrate the upper few layers of wood cells and then cure, thus sealing the wood cells from moisture intrusion. It is NOT an adhesive in the strictest sense of the word.

So while if injected into various places drilled into a rotted subdeck core it will cure and seal up the individual wood cells it penetrates, it will NOT glue the whole thing into an impenetrable mass unless you can get it to soak into every rotten and good wood cell in the bad area. Which you can't do by drilling a few holes into the bad section. You'll seal up the first few layers of wood cells surrounding each hole, but it won't penetrate into the cells out between the holes.

CPES is designed to do one thing, and it does that one thing very well. It is NOT a cure-all for large areas of rotted wood such as one gets in a subdeck core. CPES is a sealant, NOT a strengthener.

For example, in the CPES instructions that come from Rot Doctor here in Seattle, a re-seller of Smiths CPES, the illustrated cure for a rotted beam end is to FIRST cut out ALL the rotten wood. Every little bit. Then paint the remaining end of the beam with multiple coats of CPES.

THEN.... use another Rot Doctor product, a two-part epoxy paste not unlike Bondo (but better) to create a new beam end. When this cures up hard, shape it the form you want. Then paint it with several coats of CPES just to seal the surface of the cured and shaped epoxy beam end, and then paint it or whatever.

So note the VERY important step of removing ALL the rotted wood first.

CPES will seal up wood cells,but it doesn't add appreciably to the strength of the piece of wood itself. The rotten wood will still be rotten and weak if you leave it in place. It will just be somewhat sealed up. That in itself will add some strength, but nothing approaching the integrity of the original wood core.

CPES is a great tool for what it's designed to do but it's not a magic bullet by any means.

Fixing a rotted subdeck core is one of those jobs that is either done correctly or it might as well not be done at all. Be nice if there was a quick and easy fix, but there isn't.
 
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If they are small spots, a trick I use is a large hole saw. Like 5 or six inch. I cut the top layer of glass with a hole saw remove the rotten core, replace the rotten core with a piece of 3/4 pressure treated plywood cut with same hole saw. I bed the plywood with polyester resin thickened with cabosil and trowel resin mixed with chopped fiberglass over the coring slightly dome shaped over the core. I chamfer the hole about 15 to 1 before filling with glass and resin. After curing sand flush and use your choice of finish. The repair takes an hour or so. Allow the old surrounding core to dry before bedding the plywood. Larger areas can be repaired by cutting the top layer of glass and removing the coring . replace the core with 3/4 pressure treated plywood with the same thicked resin only this time chanfer the edges of the removed deck and hole. Bed old piece of deck in thicked resin and fill the chafered edges with resin and chopped glass fiber, sand smooth and finish. A 15 to1 scarf is suffient for small repairs.
 
It is one thing to sell a boat and admit there are a few pimples and take the hit...

To do a shoddy repair that is not openly visible and not fess up to it is unforgivable in my book.
 
It is one thing to sell a boat and admit there are a few pimples and take the hit...

To do a shoddy repair that is not openly visible and not fess up to it is unforgivable in my book.

THANK YOU !

someone finally said it. :thumb:

HOLLYWOOD
 
Beware posts that start: "The only way to....."
My lobsterboat (not the Willard) is cored (balsa) and I have had several deck and cabintop areas which have become soft over the many years I have owned it.
I have never had a problem making a lasting, solid repair using injected epoxy, not thinned epoxy. In each case I was able to access the area from below and drill a series of 3/16" holes throughout the area, through the inner skin and core but not the outer skin. After vacuuming out the water and drying w/ heat lamp; epoxy can be injected working across the area from hole to hole plugging holes w/ tapping screws. When hard the screws are removed and holes filled w/ thickened epoxy.
I have had the boat surveyed several times over the years, complete sounding w/ moisture meter and all; and never a word. These spots still sound like concrete when sounded.
Gorilla Glue foams up when unconstrained by the joint, and this foam has no strength so don't use that.
 
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It is one thing to sell a boat and admit there are a few pimples and take the hit...

To do a shoddy repair that is not openly visible and not fess up to it is unforgivable in my book.

I second this also Hollywood.
Proper fix is not brain surgery, route out the deck area and remove damaged core. Try a 1/16" to 1/8" straight bit in the router.
 
I agree there is always more than one way to repair something...


....but if it is an untested, non-long proven method that may or may not work....buyer beware is there...but don't make it harder than it should be...fess up.
 
I agree there is always more than one way to repair something...
....but if it is an untested, non-long proven method that may or may not work....buyer beware is there...but don't make it harder than it should be...fess up.

I mentioned the method I used exactly because I have had my lobsterboat since 1976 and several of the repaired areas are 20 years old, some 10.
Whatever method, always try to work from below and save patching where it is cosmetic.
 
I mentioned the method I used exactly because I have had my lobsterboat since 1976 and several of the repaired areas are 20 years old, some 10.
Whatever method, always try to work from below and save patching where it is cosmetic.

I know of several different ways depending on the circumstances and or boat construction...that why there is no "right" way...

My point is only that if a repair is only very temporary and is really hidden from a potential buyer....well please don't do it ...karma is a bitc*...and payback can be worse.:D
 
I hate to say it, (mostly because I have to do it), but I concur with Marin on this one. I will use epoxy to repair stanchion bolt holes, etc., but with soft areas, I'd order coring from Jamestown and do it right.
 
It is one thing to sell a boat and admit there are a few pimples and take the hit...

To do a shoddy repair that is not openly visible and not fess up to it is unforgivable in my book.

So right! If anyone searches for the vessel named My Lady, it's all on record here.
 
I can understand a small patch that you know is temporary over a few years and not wanting to commit to doing something in a grander scale. I have a few band aids as to only keep things from getting worse until I can do the repair correctly with the allotted time and funds.

As a buyer though, I would look at a sub-standard repair as a cheap way to get out of something. This would make me come in with a low ball or ask that it be repaired by a shop before purchase. This is not just relating specifically to boats. As a technician, I absolutely do not want to give a buyer any bargaining chips.
 
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