AIR-DRYING WOOD
The illustrations on page 88 show two simple ways to stack green lumber to ensure proper drying. As shown in the chart below, drying times vary for different woods. To avoid confusing different batches of wood, mark the ends of each board with the species and the date you stacked it. It is also a good idea to treat the ends of the boards with an impervious coating such as hot paraffin wax, varnish, diluted glue or a commercial end sealer. Otherwise, the ends of boards may dry more quickly than adjoining surfaces, causing checks to form in the wood. If you are working with logs, coating their ends will increase the amount of usable lumber the logs will yield by as much as 20 percent.
Whatever the size or location of your drying stack, air must circulate evenly around all the surfaces of the stock. This will ensure that the surfaces of the boards stay dry enough to pre
vent fungi from causing blue stain. It will also help guarantee a minimal amount of warping of the boards. Placing stickers, or narrow strips of
wood, between different layers of stock exposes the top and bottom surfaces of the boards to the same flow of air. Lumber can be air-dried indoors or outdoors, but for best results, you should start the process outside or in an unheated building like a barn or garage. In a heated indoor location, where humidity is typically low and temperatures are high, green wood may dry too rapidly, which promotes checking. Outdoors, the lumber should be covered with a sheet of plywood to serve as protection from the elements. As the wood dries, check its moisture content periodically with a meter, keeping notes for future reference.
Wood destined for outdoor use need only be dried outside. For indoor furniture, the wood should complete its drying inside, preferably at a humidity level similar to that in the location where the furniture will eventually be used.
APPROXIMATE DRYING TIMES FOR VARIOUS WOODS
These charts indicate the drying time for a stack of 1-inch-thick green boards outdoors. The low end of the range for each species is for lumber stacked in spring or summer—prime drying weather. The high end is for lumber stacked in autumn or winter. The figures assume that the lumber is dried in a region with a climate similar to that where the wood was cut.
 |
TWO OPTIONS FOR AIR-DRYING LUMBER
