Official Luthiers Forum!

Hello everyone!

I've been resawing some Sapele for side wood. about 0.1 for each piece.
I can gurantee that before resawing, the wood was planed dead-flat (within reason, of course) and was checked for twist too.

After taking the newly side veneers through the drum sander, and sanded to about .06 (I will use it as a lamination layer) - ALL 6 veneers developed some kind of a twist, some more then other.

I can say there was no twist before going throught the drum sander, and also not during the first few passes. it's only when it reaches the .007 area where it start to show this twist.
Also, it's not a "static" twist - meaning, the wood developed a strong feeling of spring around the middle - that can be twisted one way or the other. when I start flexing it, I can really feel this springy motion taking it to a twist (it can get easily tiwsted in both direction and stay like this - but doesn't want to stay flat in the middle).

Is it something you're familiar with?
It would be a real shame for me to toss these 6 pieces. Do you believe it's still usable? esepcially for the reason it would be one lamination layer out of two (which may be enough to stabilize it?)

Your help would be muchh appreciated!

Did you mean.070" ? Assuming you have a bending blanket/bending form set up you might bend it into shape and see if the heat from the blanket relaxes the fibers and the curves of the side holds the shape and removes the tendency to twist. The tendency to twist and cup is reduced by laminating. Plywood stays relatively flat by using cross plys and balanced construction (odd number of plys and even number of glue lines) but we don't usually laminate this way, so the benefit of stability from lamination is reduced.

That is very common. The wood has stresses that were introduced during seasoning. Laminating should take care of it. For that matter, I don't worry too much about it even when not laminating, since the act of steam bending sides tends to redistribute the stress dramatically.

Sent from my SM-G950U1 using Tapatalk

_________________
John

Just to reaffirm what John said - this is simply something that the vast majority of lumber will always do when it is thin.