Warped Madagascar Rosewood Back

[Philip Secrist]

Hi guys! Happy New year!

I pulled out a set of Madagascar Rosewood back and sides from my stickered storage (about 6 years) and discovered that the back halves have cupped or warped (one side more than the other. See Pics). Is there anything I can do to try to flatten them out?

[Peter Wilcox]

If the back is to be radiused, it would be nice if they are both cupped in the same direction when they are book matched (but usually not), and if so, I don't think it's a problem.. However, it would be better if they are flat when you prepare them for joining and join them. I have had some success in eliminating cupping by wetting the concave side and clamping it flat until it dries; may have to repeat several times for long lasting, but they will probably flatten temporarily just by wetting. As always, YMMV.

[Chris Watts]

Happend to me, too. I was told this could happen, because the vendor didn't treated both sides the same way, for example one side was sanded to show grain, the other side shows plane or saw marks.
I wiped some water on the concae side, and as soon as the plates started to be (more or less) flat I sanded them to thickness (from both sides…) and dried them between clamps. It stayed flat…
But im really not an expert…
Sorry for my bad English
Chris