Question

[Ron Nossaman]

> Actually you can end up with a CC board even if it is at 6% MC when ribbed.
> Probably even higher. I don't know how far you could stress the system before
> you started running into problems. 
> 
> You just have to press it up in cauls with enough crown. Still, of course, with
> flat ribs. Don't ask me what that caul radius might have to be -- I've no
> interest in working it out. 

Since I made the comment, I did. Theoretically, yes. 
Practically, maybe. To get the same compression level at 10%MC 
(70°,55%) with 6%MC in a curved caul as you did with 4%MC on a 
flat caul at the time of ribbing, you'd have to press the 6%MC 
panel into a slightly less than 4M radius caul for a 20mm deep 
rib and 8mm panel. About 31mm dish for a 1M rib.

Still compression crowned, however it's done.

Ron N