Early military planes employed Douglas fir of their development – biplanes, and tri-planes of WW I. Our suggestion might be to implement sawdust from Deciduous trees, such as Oak, Beech, Maple and Elm. The sawdust from these trees breaks down and decomposes reasonably promptly, absolutely the most suitable choice. https://mylesducbz.jts-blog.com/27593957/not-known-factual-statements-about-douglas-fir-sawdust-for-sale