Straigtening cupped wood

[THIRSTYGUMS]

I have a nice flamed bookmatched maple top thats been lying around for a while and has cupped quite badly along its width, can this be straigtened out with a press or clamps e.t.c? anyone have any experience with this?

 

[wilser]

I tried this method suggested by Larry from gallery hardwoods. It works great, but keep in mind that you must do this about 30mins to 1 hour before glueing the wood as it will go back to it's cupped shape after a day or so.

Spritz some water on the cupped side (where it seems dipped in). Wait several minutes and watch it straighten itself out. The amount of water will depend on the density of the wood. For my particular curly hard maple it took about 4-5 spritzes (is that a word?) on a single bookmatched side.

 

[Cerb]

Am I correct that this method works because the pores on that side absorb the water, thus forcing the non-damp side back out?

 

[PaleMelanesian]

Exactly.

Another way of doing the same thing is to lay the piece out on the grass on a sunny day. Lay it so it cups down (like this ^ and not like this v). This works because the upper side is being dried by the sun and shrinking, and the lower side is getting moisture from the grass and expanding.

Watch it closely! It'll only take minutes, and can easily end up cupped the other way if you're not careful.

 

[THIRSTYGUMS]

ooooh, sounds fun! Cheers folks i'll try it.

 

[Keith Guitars]

The sunny day thing works!

I'm siding my new shop (hooray!), and the uppermost plank
on the pile of rough-cut 1" pine will cup up towards the sun
in about an hour or so...turn it over, and it will reverse its
position (convex to concave) in another hour or two.

It's kinda entertaining. Compared to hammering nails, anyway.

Peace,
Martin

 

[FBB Custom]

Am I correct that this method works because the pores on that side absorb the water, thus forcing the non-damp side back out?

Not the pores, but the fibers.