Who needs confusion?
Clamp GG’ed pieces tightly.
Don’t clamp too tightly.
Dampen the surfaces well.
Don’t dampen them too much.
I am a small-time tinkerer. I do not want to experiment. With Titebond III yiu spread it, clamp the pieces tightly, clean up excess with warm water, and I am good to go.
happy as a clam with TB-III
Who needs confusion?
is always good stuff. I’ve not been impressed with Gorilla…
With any glue, tho, clean, smooth surfaces, and enough, but not too much, clamp pressure (to avoid starvation) is critical. Reminds me of an old Ferrari mechanic I used to know - How tight do you torque head bolts? You make 'em atight buta not too tight… alternatively, torque 'em till they break, then back off about 20 foot pounds!
If all else fails, consult the directions.
That’s mainly an issue with epoxy…
…since it flows out of a joint easily when clamped, unless you thicken it. It would be very hard to starve a joint glue with polyurethane, as it’s thick, tacky and doesn’t flow well.
PVA-1 isn’t waterproof…
…(though some versions of it are water “resistant”), which is a pretty good reason not to use it on a kayak paddle.
The open time, is about the the only benefit to urethane over PVA’s. It’s nice to have ~30 minutes to do a complex glue-up rather than the hurried feeling I get with PVA.
That said, I use PVA’s for 98% of my furniture-making. Mostly just Titebond I, unless I think I need a couple more minutes open time, then I’ll go to the III. None of my furniture goes in the water though…
Epoxy is so easy to work with, I’ll use that over urethane for in-water applications.
FWW article was interesting, especially since they varied the fit of the joints they tested, a real-world practical situation. However, I’m very skeptical of any “test” in commercial magazines. Too much potential for conflict-of-interest.
Joinery > glue
As mentioned above.
Well-designed and well-executed joinery is 99% of what determines the strength and durability of joining two pieces of wood. If you want good joints, knowledge and skills are what really matter.
Every wonder older chairs made well with only hand tools and hide glue may be sound for hundreds of years of use; whereas, cheaply designed and manufactured chairs fail routinely, even with every technological advantage of the 21st century???
Gorilla glue failure?
After posting above that I have seen no glue failures in 15 hollow shaft greenland paddles blanks glued with Gorilla glue for a club paddlemaking class, I had a surprise yesterday. A club member came up to me at a pool session and asked what to use to reglue a split in the hollow shaft paddle he bought from another club member. Who carved the paddle doesn’t matter (except for my comments on finishes below) as I glued up all blanks.
The paddle had a 8" split on a glue line, starting at the end. There was a substantial dent at the end where he had hit rocks causing the split. However, the split was in the glue line, not the wood adjacent to the glue as I would have expected. Because the split was in the glue line, not in the wood, I would call this a glue failure.
There are extenuating factors. The split was caused by contact with rocks. Also, he reshaped the paddle and was using it bare wood with no remaining finish. I had instructed all class participants to wipe epoxy on the paddle paddle to harden the soft cedar a little and to prevent water intrusion. Oiling the paddle after the epoxy coat dried was also recommended. He knew my recommendations for paddle finishing (his wife made a paddle with me) chose to ignore them and use it with bare wood. Gorilla glue is marketed as waterproof, so this shouldn’t have been a factor, but I had stressed epoxy coating as a extra caution not fully trusting any glue in water and that recommendation wasn’t followed.
Two other club member at the pool were using their light weight hollow shaft paddle (both coated) and have had no glue problems. Still I find the fact that the split was in the glue line disconcerting and have to amend my statement above.
Yes it is… (sheesh)
ANSI/HPVA Type I… There aren’t “some” PVA Type 1’s that are “water resistant,” they all by definition meet the standard. So they may not be suitable for continuous submersion… Neither is Gorilla Glue.
And just so you know, Gorilla Glue only meets ANSI/HPVA Type I… the same as ANY PVA Type 1.
The whole issue is a myth
The type of clamping pressure anyone is going to get is not going to be anywhere near enough to “starve” a joint. This is documented stuff.
are worth attempting if they don’t always stand the test of time? What is the warranty worth when it won’t cover the time and wood that was wasted? As a builder, I largely disregard new products that hit the market. Imagine finishing the paddle and selling or donating it.
Use marine epoxy for everything.
One thing I noticed with Gorilla Glue is that you have to moisten the joint before applying the glue.
It doesn’t work at all on dry surfaces, so I went back to Titebond 2 for all things I might have to sand later.
Epoxy is great, but it is harder than wood, so sanding a joint that it was used on always makes a lumpy end product.