warping of lumber before I've even started

[Ron Daves]

Hi, all
I don't usually get into trouble until after I've started a project. However, I'm going to need some help:

I've got a set of book matched Macassar Ebony for a concert ukelele project. This lumber was sawed up on the Oregon coast and shipped to me in the California desert.
In a month, one piece has a developed a slight curve across its width, the other across its length. I suspect that I can get this lumber flattened out with the right process. Please give me some input.

[Ron Daves]

Good News!
I made a sandwich of 3/4" ply/2 pieces of the book matched lumber/3/4" ply and a dozen clamps. I've tightened the clamps gradually over a couple days and it's looking good. I'm thinking this is a lesson that while newly acquired lumber is getting accustomed to a new environment, it's a good idea to keep the lumber in a sandwich until one is ready to start his project.

[Mario Proulx]

The correct advice is to always sticker newly acquired wood for a few weeks for them to acclimate. Placing them in a sandwich like you did will prevent them from getting acclimated.

On really badly twisted pieces, I would wet them, and place them in a sandwich like you did, but with a thick layer of newspaper on each side, to blot out the water. Change the paper daily, and it should remain flat after a few weeks...

[Michael Lewis]

As long as the plywood is not sealed and not exterior grade it should allow moisture to escape from the subject wood. It may take a little longer but it will work just fine.

Mario is correct about new wood being kept flat. Don't let it warp, and make sure it is dry before you glue it up and it should be good.

[Ron Daves]

Please advise as to what "stickered" means in instrument building. I've stickered lots of firewood and lumber, but wasn't worried about keeping it flat.

[Michael Lewis]

By placing "stickers" between the pieces (plates) of wood air is allowed to circulate to dry the wood, and stickers, plate, stickers, plate, stickers, plate, stickers, and so on, and placing a weight on top of the stack or tying cord around the stickers to hold the stack together gently forces the wood to remain flat while it dries. This is used for drying the wood, once it is dry it can be stacked and stored in much less space.

[Ron Daves]

I "stickered" my lumber by guess, then read Michael Lewis's post which confirmed that all is well. See pic.