Boards emerge bright, check-free
Synopsis: Curtis L. Johnson of Madison, Wisconsin, has designed and built a sun-powered kiln for drying small quantities of furniture-grade lumber. Johnson’s kiln is slower than a steam kiln, but gentler. Paul J. Bois, a wood drying specialist, writes in this quick article about how the kiln is built and works, how Johnson monitors it, and what the moisture rates are as the wood dries, winter and summer.
Curtis L.Johnson of Madison, Wis., has designed and built a sun-powered kiln for drying small quantities of furnituregrade lumber. His kiln is slower than a steam kiln (Fine Woodworking, Spring ’77), but it is gentler. The boards emerge bright and clear, with virtually no checking.
The kiln is an insulated, stud-framed wooden box that measures 10 ft. wide and 12 ft. long at floor level. It holds 800 bd. ft. of lumber in two stickered piles. The south wall slopes 40°…