On 16 Aug 2006 03:56:04 -0700, "Lou" wrote:

I've always wondered about that. When gluing wood together it's always
been a good idea to rough up the area's to be glued so that the glue
goes in the roughend area and has a better grab. If the area is too
smooth it will hold less glue and more possiblity to squeeze out.

glue beam laminators have noticed that you can get beams about 20%
stronger if the wood surface is freshly prepared just before gluing.
they are not certain why but oxidation or some other chemical process
occurring on older wood surfaces may be a culprit.

on plywoods of course the reason is different. it removes surface
contamination from the presses.

Stealth Pilot