California black oak drying problems and the bacterial factor

Abstract

It is often difficult to kiln dry California black oak lumber green from the saw without developing excessive degrade from honeycomb, ring failure, and collapse. Results from this study indicate that defect-prone lumber contains heartwood that was infected and weakened by anaerobic bacteria in the living tree. Green, bacterially infected boards should be segregated and dried to 20 percent moisture content (MC) under mild air-drying conditions or by low temperature, forced air-drying schedules. The percent MC lumber can then be kiln dried to end-use MC without additional defect. Boards with normal, noninfected heartwood can be successfully kiln-dried green from the saw under conventional schedules.

Citation

Ward, James C.; Shedd, Del. 1979. California black oak drying problems and the bacterial factor. Research Paper FPL-RP-344. Madison, WI: U.S. Department of Agriculture, Forest Service, Forest Products Laboratory. 14 pages