Warping blind slats

[BOB OLINGER]

I've been making a lot of plantation shutters. I'm re-sawing red oak to
about 1/2" thick, then running through the molding machine (2 passes - one on each side) to make the shutter slats. After molding, some of the slats come out warped (or curled). I can solve some of this when the slats are cut down to finished length. However, some still have enough bow that it is noticeable. I also made a lot from poplar, but they seem to be nice and straight. Does anyone have any suggestions on how to eliminate this? Thanks in advance.

[Neil Brooks]

My only guess would be that you're releasing "internal tension" from the wood, when you cut it.

Can you cut it ... then ... let it sit for a week ... and THEN plane/finish it, to final size ??

[mark r johnson]

Try using some quartersawn oak and make sure it's dry. It should be more stable than flat sawn.

[BOB OLINGER]

Thanks for the ideas. I'd guess using quarter sawn would be an improvement, but I'd need to weigh the added cost vs discarding a percentage of regular sawn. This is only a hobby, so I'm not too fast. Usually the resawn blanks set around for several weeks before I get them through the molder. They do set near the floor of my basement shop - I have a dehumidifier running most of the time, but there might be some chance they're picking up some moisture. On the other hand, the poplar hasn't warped. I'm guessing more of a thing related to the oak after being thinned down significantly.