1/2" red oak panels curling when edge jointed after resawing

[Jeffrey Schronce]

sorry jeffery for the misunderstanding. the 15 wide or 12" wide boards are made up of two or three boards glued togather. the stock was 5/4 varied widths and then were resawn individually, surfaced and put through a thickness planer to get 1/2" stocks. then they were glued togather and then the boards were cut to width. then a pattern was routed into the edge of the boards and were set to be finsihsed. this was done all in one day. when my friend noticed that they had started to cup. they cupped upto 1" in one day after rasawn.

Ok. So that leaves moisture content, which of course can be measured, and "wild-ass-springy-board" or "reaction" boards which of course can not be measured.

What type of profile was put on the edge? Was it thinned down a lot, resultining in real thin edges that cupped?

[Anna]

One question: If moisture caused the warping, would it have helped if a finish was applied to the panel as soon as it was assembled? Or would that just postpone the inevitable?

[Jeffrey Schronce]

One question: If moisture caused the warping, would it have helped if a finish was applied to the panel as soon as it was assembled? Or would that just postpone the inevitable?

Finishing with a film building barrier coating like poly or shellac would likely help with this issue. Even a light wash coat of shellac on sides and edges would likely help this issue. The problem is not so much the drying out but the *speed* of the drying out. At 5/4 it was not as likely to cup, warp or twist by air drying as it took a long period of time for the moisture inside the slab to make its way out. Additionally the 5/4 has much more material to support against stress of drying. Once it was resawn and planned to 1/2" material the thickness was a problem due to speed in which interior mositure content could escape PLUS thinner stock is easier to cup/twist/warp, thats why we use thinner stock for laminate bending.

This thread also brings up the fact that we should attempt to remove equal amounts of surface from both sides of a piece of wood, particularly if the moisture content is above 6-8%. In the case at hand the 5/4 stock would have been face jointed on one side a few passes and then surface planed on the other side a couple passes. The 5/4 would have been resawn in half, then the originally flattened faces would be face down against planner bed to create a parallel board. It would be easy to keep surfacing the freshly cut side instead of equaling out the material removal once both sides are parallel to each other. Failing to try to equal out freshly exposed wood surfaces will also lead to cupping/bending/warping.