Working with Green Lumber
I am making a fireplace mantle from a cherry log that has been left outdoors for two ears. The wood still seems very moist. I’d like to mill it down to 6 in. thick by 10 in. wide by 66 in. long for a single-piece mantle. Can I use this over my fireplace after I seal it?
David Stafford, Aurora, OH
If the log is not dry when you install it, the mantle will warp and check along its length whether you seal it or not.
Even indoors, the log will take years to stabilize. Heat from the fireplace will only increase the problems as the exterior of the timber dries more quickly than the wetter interior.
Bring the log indoors and let it dry for as long as you can wait. Cut the initial workpiece 1/2 in. oversize in width and thickness and 6 in. or more in length, so you’ll have enough wood to mill away when truing it up after it dries. If you can’t wait until it dries slowly and completely, consider a trick that might limit checking.
Cut a sawkerf about 1-1/2 in. deep into the center of the back edge and another in the middle of the underside, where they won’t be visible. The biggest (with luck, the overall size is 6 in. thick by 10 in. wide by 66 in. long. only) cracks will open along these kerfs.
Once you install your mantle, finish it as you would any woodwork.
Drawing by Kelly J. Dunton.