Another Glue Question

[Jay Greer]

Having been in the business of building boats and masts for over forty years, I have my own favorite glues.
But, now my two old reliables, Weldwood Plastic Resin Glue and Resourcinol are banned in California. Yes, I can get them via the underground but, I am wondering if Gorilla Glue can be trusted for spar making or any other marine use for that matter. Of course it says 100% waterproof on the label. But, how Gorilla Glue or others of the same family hold up over the long run?
JMG

[Venchka]

OK, what on earth is so bad about those glues that the kindly folks of California have lumped them in with nuclear weapons and Louisiana oysters?

Just a hunch, but I guess that if you remove California from the market, those glues will disappear everywhere else soon.

Did you read the 7 year old polyurethane test I posted today? No brand names, sorry. Bottom line: Wet polyurethane doesn't work.

Suggestion: John Guzzwell became sensitized to epoxy. He built the cold molded Dolly using Borden Wonderbond. He went so far as to coat the inside of the hull with it. I don't know if he used it for the spars. I also have no clue if Wonderbond is available in consumer quantities. You will have to contact Borden.

Can't you see it now: VW bus stopped at Oregon-California border. "But officer, I didn't know that glue was back there. It's not mine, honest. Somebody else must have put it there." :eek: :rolleyes: :D

Wayne
In the Swamp. :D

[ 06-28-2005, 03:43 PM: Message edited by: Venchka ]

[John of Phoenix]

I've used epoxy for the most part, neat or thickened with silica, and never had a problem. I recently used Titebond II on some joints, but not yet enough time on the water to make a personal report. The new Titebond III is billed as water"proof" passing the type I test below. None of the above foam like Gorilla, which can be a bit messy.


What is the difference between the ANSI/HPVA Type I and Type II
water-resistance specification?
Both of these tests are conducted using 6” by 6” birch laminates glued together to make three-ply plywood. The test for Type I is clearly more stringent than Type II, and involves boiling the glue bonds and testing the specimens while they are wet.
Type I testing involves cutting the 6" by 6" assemblies into 1" by 3" specimens, boiling them for 4 hours, then baking the specimens in a 145°F oven for 20 hours. They are boiled for an additional 4 hours, then immediately cooled using running water. The specimens are sheared while wet, and the bonds must pass certain strength and wood failure requirements to pass the Type I specification.

Type II testing involves cutting the 6" by 6" assemblies into 2" by 5" specimens, soaking them for 4 hours, then baking the specimens in a 120°F oven for 19 hours. This is repeated for a total of three cycles, and the bonds must not delaminate to pass the Type II specification.Wayne, the oysters comment. :D

[Bob Smalser]

I'd try it on a small spar and see how it holds up, Jay. I suspect it'll last as long or longer than U/F Resin, my favorite glue for indoor work. I've used poly for outdoor wood ever since it came out with terrific results. Been 15 years, now? I'm using it on oars and other thick layups likely to starve an epoxy joint from heavy clamping pressure.

The USDA test is about fully-saturated wood causing the glue joint to fail. Heck....there have been epoxy failures under that scenario...and I can personally vouch for 3M 5200 losing all adherence in saturated cedar. Resorcinol is the only on-the-shelf glue out there that's 100% reliable in fully-saturated wood.

I buy Elmer's Probond or Elmer's Ultimate in preference to the more-expensive Gorilla brand.

It's not as temperature-sensitive as resin, but it requires joinery that's just as tight. It won't fill gaps at all, in spite of the hype, and it needs tight clamping pressure....at least as tight as resin and maybe as much as resorcinol. I've had failures with it when I used it in the rain and the wood was too wet, but I've never had a failure from too much clamping pressure. It's perfect for green and airdried wood....kilned wood from indoors should be dampened, first.

My only concern is getting enough clamping pressure on those hollow spars, and the lack of gap filling aboility, as I haven't seen a 100% perfect birdsmouth joint fit yet down the entire length of a spar...conventional coopering might be more suitable.

[Jay Greer]

I'm going to give poly a try on a small mast repair job that requires a six foot splice at the butt. Still I am leary of trusting it to a 45' hollow spar. The aspects of having it let go could be disasterious! I have written to the mfg. of Gorilla Glue twice but have never recieved a reply. Doesn't speak well for them!
JMG