To the Editor:
Reading in last week’s Advocate about using waste sawmill wood to generate electric energy and district (community) heating I am reminded that I should report on my last winter’s sawmill work.
Last year there was considerable discussion as to how much of a log ended up as waste wood after the lumber was sawn out. Several big industrial sawmills published they were getting only about 50 per cent of the log as sawn lumber. I knew from experience this was not true unless the sawmills were not using current technology available to them. Modern mills use scanners with computer programing to get the most out of every log — no two logs are the same. Old circular main saws have a loss due to the wide kerf (width of the saw blade) that becomes sawdust. On an average log at least one inch is lost to sawdust versus half that loss from a bandsaw blade. Band saws leave a smoother surface on every board and can be used without being planed on many jobs, thus more boards from every log and far less waste.
Last year I bought a basic bandsaw mill and since then have sawed many logs. The result is that I consistently get 70 per cent sawn lumber from most logs. Crooked logs and tapered logs reduce the sawn saleable amount. I am left with thinner slabs and edges removed.
Sawdust has several uses and markets and is in demand. What to do with the slabs? So far, I make fence upright boards, garden raised beds and customers stop by and buy some for various uses. The remainder are only fuel wood. They should be chipped and spread over the forest floor to become organic matter food for growing saplings. Chips also prevent evaporation of rainfall and snow melt. But I don’t have a chipper — so far.
A bandsaw mill is said to be slower than old circular saws and thus need to be used as a main initial sawmill that feeds to a board edger. These mills are best when three persons work the various jobs. Production increases in a system that gets more saleable products from every log.
Some forest owner co-ops are switching to bandsaw mills with edgers and planers with the result they get a better end revenue for logs harvested. Currently, lumber is in great demand and at a historic higher price.
Let’s not cut trees for fuel wood — there is plenty of real waste wood. There are bandsaw systems that can process small diameter raw wood; others are best suited as re-saw mills.
The best collection and storage of CO2 and other emissions are trees — especially large adult trees. Trees work very cheaply compared to industrial CO2 collection systems.
Trees also maintain aquifers storing water for human and plant use. They release oxygen.
Trees support eco-tourism. Clear cuts are not tourist destinations. Trees are homes to migratory birds that feed off of bugs that harm forests — unless those home trees are cut down — especially during nesting months. Also don’t spray herbicides that harm all forest life.
The bottom line is: Harvest fewer trees, process them smarter, and realize more revenue per tree.
Brule Point, NS