Can I dry wood in the oven?
When a friend cut a large maple log in half for firewood, the inside was beautifully spalted throughout. He cut it into 12" pieces 18" long for me. Can I dry these pieces in the oven, or would it be better to air-dry them? (I'm eager to start on a mantel clock I want to make from a WOOD® magazine plan.)
—Mark Ball, Duluth, Minn.
Oven-drying or microwaving wood could be a recipe for trouble, Mark. Drying those 4"-thick pieces in a kitchen appliance invites splits and warps, warns Richard Bergman, research chemical engineer for the USDA Forest Products Laboratory. Instead, coat the freshly cut ends with polyurethane finish, and allow the pieces to air-dry in a place protected from rain and snow.
"Air-drying and sheltering the pieces while allowing air flow would be the best method, unless you know of a small custom kiln dryer, preferably a vacuum kiln, which would be quite expensive," Bergman says. "Air-drying the pieces would take a couple of years, but allows a gradual drying to minimize drying stresses for thick lumber."
The good news is that the wood may already be dry enough to use, considering that spalting forms in trees that have been dead long enough for the wood to begin decaying. Check the pieces with a moisture meter, as shown above, to see whether they're between 6 and 8 percent. If they're close to that, consider allowing them to air dry the rest of the way.