Ordinary wood glue, for instance Titebond original, is infamous for cold creep. Does anybody know if the modified PVAs like Titebond II or Titebond III creep less?
[OP]
Contributor
Ordinary wood glue, for instance Titebond original, is infamous for cold creep. Does anybody know if the modified PVAs like Titebond II or Titebond III creep less?
Contributor
That's a good question. I suspect the TB II would creep a little less than original, because it seems to cure a little harder. I don't think I'd use it on any crazy bent laminations though.
Contributor
I've used it and not seen creep. But mainly I use the powder Weldwood stuff. I still say creep is an old white glue thing.
You could ask the Titebond reps, they always answer fast.
Moderator
I've experienced "creep" with TB-III for sure...
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The most expensive tool is the one you buy "cheaply" and often...
Contributor
Yeah, nobody likes Titebond 111
Contributor
Any thermoplastic glue will creep if the temperature and stress is high enough to exceed the shear strength. I know lots of folks say they use PVA type glues w/o issue. I'm sure it's true as long as the temp. and stress levels are low enough. But like Jim, I have seen creep with TB type glues (had to be Original or TB II because III hadn't been invented yet) in simple flat laminated table legs. Every year I can feel the joints as the two 6/4 pieces of stock move with the seasonal changes in RH. I sure wouldn't use TB III for an exterior door that will get any exposure to direct sun.
John
Contributor
They all creep for me and with regards to sun/heat just leave any one of them in a car in the sun (even if they are not in the direct sun) for an hour or two and you'll see immediate glueline failure. It gets worse the higher up the "ultimate" chart you get. TBIII will fail in a vehicle in an hour or less. That's a pretty extreme test for their ultimate value.
https://www.finewoodworking.com/2015...de-to-pva-glue
https://www.finewoodworking.com/2007...g-is-your-glue
https://www.finewoodworking.com/2013...nt-laminations
If glue creep is really an issue, it would seem Unibond 800 is your best bet.
Mike
Last edited by Mike King; 09-10-2019 at 3:55 PM.
[OP]
Contributor
Unibond 800 is a urea-formaldehyde glue. I used to use it for bent lamination, but stopped. I was concerned about formaldehyde exposure. Formaldehyde is a known carcinogen, and the whole building industry is moving away from it. Now I use epoxy when I need a no-creep glue, and when I'm willing to use a two-component glue. I keep hoping to find a one-component low-creep glue, hence the original post in this thread.Originally Posted by Mike King
Contributor
Seems the only one part option with no Formaldahyde (reasonably speaking) is PU which sucks for the mess. Im running epoxy as well as opposed to UF but I dont know which is worse for mess, epoxy or PU. If you can get pretty accurate with PU the mess can be minimized but without a doubt if you wanting to ensure full coverage there is no way around it. Epoxy is really no better in that regard so I have been holding epoxy back for the most extreme situations.
Contributor
Mark, are you aware that white vinegar cleans up wet epoxy easily and completely? I never knew that until I read it on the back of a System Three T-88 bottle.
John
Contributor
I did not know that, and it will be a bit of a game changer for me when using epoxy. Thanks for posting.
Member
Just be sure to wash it off your hands ASAP...as I understand it, the vinegar emulsifies/makes the amines water-soluble, increasing chances for skin sensitization...
Gojo Orange is also good for cleaning up green/wet epoxy.
Contributor
Unibond 800 works great, especially in a vacuum bag where the pressures are low. Weldwood Plastic Resin Glue works well, too, but according to the instructions requires much higher pressures, higher than what you can get in a vacuum bag. I used to use mostly PRG because it was easy to obtain but I'm switching back to Unibond 800 after having a couple of bond failures with shop sawn veneer. But both products have essentially zero creep and I have used them for many bent laminations w/o problems.
As far as the formaldehyde in both products, everyone has to decide for them self what risk they are willing to take. Gasoline has benzene, another known carcinogen, and most of us fill up the tank on our car, lawnmower, etc. w/o even thinking about it.
John
Contributor
Thanks John,good detail. I've used a lot of the plastic resin stuff for glueing up large ellipses. In those cases the only
"clamps" are the lumber banders. Bands are no closer together than 8 to 10 inches. And in the middle flatter areas I can actually pick up the plies an inch or more off the form. I've always put glue on both sides,
I ve seen some try "heavy coat " to just one side . That did not work. Never used Unibond but always heard its "the real
stuff".
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