Teardrops n Tiny Travel Trailers

My local plywood supplier suggested that a non-hardening glue would be better as hardening glue can cause plywood delamination over time due to expansion/contraction /vibration of the sheet. If the outer layer of the plywood is hard glued, then the inner/opposite layers will want to shear away under stress.

Maybe someone with more expertise can comment. I was leaning towards titebond III or similar for my all-wood build (not a foamy),

Thanks,
Doug

DougN wrote:My local plywood supplier suggested that a non-hardening glue would be better as hardening glue can cause plywood delamination over time due to expansion/contraction /vibration of the sheet. If the outer layer of the plywood is hard glued, then the inner/opposite layers will want to shear away under stress.

Maybe someone with more expertise can comment. I was leaning towards titebond III or similar for my all-wood build (not a foamy),

Thanks,
Doug

Doug:

I've been working with wood for over fifty years and have never heard of this issue. In fact, I don't even know what he means by a non-hardening glue. The glue used to laminate plywood -phenol-formaldehyde- seems cure as hard as a rock. Perhaps some body else can straighten me out on this.

A proper wood joint will not fail with either Titebond 2 or 3 (the wood will fail first). I prefer TB2 since it'll stick to previously exposed surfaces with TB2 but you can't do that with TB3.

T

A glue that did not harden or dry completely would make a joint that was subject to creep over time. When we glue wood to wood with a PVA glue like titebond, and clamp it properly, we end up with a joint where the glue is stronger than the wood. If you break that joint the wood fibers will tear. IMO, that is much preferable to using a glue that leaves the parts to move. Using a PVA glue once the joint is cured / dried the joint may be stronger than the fasteners, especially if the fasteners are a few finishing nails.

Thank you for the detailed responses! The lumbar guy must have misunderstood my intended usage. Titebond II it is! Picked up a small bottle to experiment with.