Up until about 15 years ago, I over tightened everything… but not anymore.
On well machined pieces.
Since then, here’s what I do. On panel glue ups for example, I have used moderate pressure and watched my squeeze out as a gage of how tight to tighten the clamps. With a moderate amount of glue, I’m using finger pressure while turning my wrist and when I get a nice, even squeeze out I stop. With ¾” pipe clamps, say every 12” or so (3” boards), clamps on bottom and top (tops used to bring opposing force to keep the panel level only). When everything is nice and flat after finessing with a straight edge, I let it dry.
I have never had a glue failure with this method. I use the clamps more for equaling pressures and pulling things into level or square than consciously thinking about how tight they “must” be.
On another forum, I was reading how they do it. There, they crank ‘em to max and “engineers” and “physicists” supported that… stating that 1800 psi per clamp was justified in order to comply with the following info:
From the Titebond website:
>>> Required clamping pressure Enough to bring joints tightly together (generally, 100-150 psi for softwoods, 125-175 psi for medium woods and 175-250 psi for hardwoods)
I would really like to hear what experienced woodworks have to say about their clamping techniques.
Edited-out image HTLM.
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