Join Date: Jul 2008
Location: Dickinson, Tx. / Somerville, TX
I dont know how much pressure in PSI you should use but I'm sure you can look it up.
From a practical side, you should use enough to make it tight and glue to ooze out. How tight is tight? Hard to describe. You dont want to use all of your might or even close to that for tightening or you will force the glue out. Also, if you need to use all of your might to clamp a warped piece in place, better rethink using that board. The glue is normally applied at about .005 to .009" thick. When clamping, it will squeezed out to about .001 to .002" including some glue that actually gets absorbed by the wood. Thats is less the 1/2 thickness of a piece of paper.
Keep in mind that wood glues are meant to adhere 2 pieces of wood together. The strength is in the adhesion and not in the thickness of the glue itself. Hard to explain so feel free to shoot this full of holes.
Retired woodworker, amongst other things, Sold full time cruising boat and now full time cruising in RV. Currently in Somerville, Tx