ON THE CUTTING EDGE

BY JOHN HEBERT, HEAD FILER,

GORMAN Bros., Westbank BC.

The year 2003 will be long remembered in British Columbia as one of the driest summers ever experienced. Many homes have been destroyed and families will need to rebuild what was lost. We have also been left with a huge volume of burnt timber and scarred, blackened landscapes; now the cleanup and rebuilding begins.

Many of the standing trees are not too badly burnt, but often the root structure in the ground, which gives the tree strength, is gone. For reasons of safety, replanting and future logging, these trees need to be taken down. The mills also need to deal with, and try to salvage as much burnt timber as quickly as possible before next summer's heat. If the timber becomes too dry, excessive check and splits take their toll, dropping the value of finished lumber dramatically.

Because the trees along fire breaks and roadways were taken down with a great deal of urgency, the logs arriving at the mill site are inconsistent in length, thereby increasing the trim loss as they are cut to proper log length for processing. We may need to increase pressure on debarker tools to remove most of the badly burned wood fiber under the bark. Due to the dry, charred fiber, water is sprayed on the log just prior to sending it into the debarker to keep the black dust to a minimum. The debarkers may not remove 100 % of the ash, and as the logs are made into lumber, the byproducts such as chips and sawdust are certain to contain ash. Consideration is being made to bring a portable debarker into the areas of fire-damaged forests to process the logs before bringing them to the mill site. This leaves the bulk of the bark and blackened ash in the forest, instead of the mills trying to handle it.

Pulp mills need to deal with the negative results as well. Due to the widespread fire damage, most mills will be cutting a certain amount of charred logs. Tentatively, the mills will accept lower quality or contaminated chips, but plan on segregating the byproducts and to make a different type of lower grade pulp. A good practice in the sawmill is to sort out the burnt logs and run them in separate batches.

Sawing lumber from the burnt logs should not cause too much of a problem as long as most of the ash is removed from the logs prior to sawing. To date the seared logs coming in to the mill have not been too much of a problem, as most of the fire has primarily scorched the bark with minimal damage to the cambium layer. Most of what we have seen so far is timber taken down to make firebreaks or for road building; therefore it is almost a certainty that we will see much worse in areas where there was buildup of ground fuels and beetle kill, causing the fire to burn more intensely.

When the log has been burnt past the cambium layer, we anticipate the saws cutting into some of the charred timber that is very abrasive. This may cause additional saw changes due to premature dulling. Some research is to be done as to which cutting tip (carbide versus stellite) is best suited when sawing burnt logs.

 After the lumber is sawn, dried and planed, a small amount of seared wood maybe spotted on the occasional piece of lumber. Blackened wood is most evident in the areas of wane or various other defects in the board, which may not have been removed during the manufacture of the lumber.

The full impact of this past fire season remains to be seen, but r mills will need to work through it in their own way. Let's hope next fall brings a different look to the lumber/logging industry in British Columbia.

If you have any comments, ideas or questions of interest regarding the saw filing trade that we can use in this column, please send me an e-mail; jehebert@telus.net