Three boards really close to the pith, in the center too, will do that. Those also look pretty wide, which only exacerbates the problem. How long did you let these dry after milling? Were they all totally flat when you glued them up?
Unfortunately there’s no saving it in its current state. Your best bet is rip all three apart, then rip the three boards in half, ideally removing the center inch or two (the area most prone to cupping) when you do so, and regluing the now 6 pieces
Is there an option to shallow cut underneath the concave and allow the bottom side to stretch or top side to shrink assuming the C bar will stabilize the stretching movement? Or will that definitely make it crack?
Edit:
You want to cut out a channel and attempt to bend the wood back to flat? You'll surely split it at the pith if you tried that, especially since you'd be removing the stronger part of the pith. You can't bend wood that thick, so you'd be removing a ton of material (leaving at most 1/4"). And if you did, without making the area super thin, it'll probably cup back
83
u/thoang77 5d ago
Three boards really close to the pith, in the center too, will do that. Those also look pretty wide, which only exacerbates the problem. How long did you let these dry after milling? Were they all totally flat when you glued them up?
Unfortunately there’s no saving it in its current state. Your best bet is rip all three apart, then rip the three boards in half, ideally removing the center inch or two (the area most prone to cupping) when you do so, and regluing the now 6 pieces