Spring is here, and we may finally be able to put the wet weather behind us and tackle the many challenges that are a direct result of the winter weather. As a former logger and sawmill owner, I have lived through weather pitfalls. Let’s discuss.
As a logger, once the rain starts falling, you are restricted in many ways by nature and as a result, you adjust your process. One adjustment I always made was to never stop cutting trees. Instead, I simply stockpiled them in the woods and waited for a clear, dry day to haul them to the mill. This was the only way I could exist in the logging industry, but it does have its negative side effects – number one being STAIN.
After a very wet season, sawmills will notice a lot of logs that seem to be much older and show signs of degrading. This condition is directly related to the length of time since being cut and then the time spent stockpiled. It is critical to implement the practice of “first in – first out” inventory strategy, immediately after a long, wet season.
I have heard it said, on more than one occasion, that the lumber was “dead-piled” for too long and thus the reason for stain in the sapwood. The fact is, wood begins to dry immediately upon the first cut, so it should be processed immediately, and the drying process controlled to minimize the negative effects to the wood.
This brings me to my point for this month’s article, stain and its effect on grading. As we begin to cut lumber from the logs that were in a very bad environment for drying (piled at the landing), we start to see streaks and discoloration from the ends of the log and sometimes in areas where the bark was scraped off. This is considered stain, whether enzymatic or fungal and will cause degrade in the lumber.
I have witnessed several strategies over the years to try and combat staining and they all involve inventory management. Although cutting the oldest logs first may not coincide with your need to fill orders on quick turnaround species such as poplar or soft maple, it is the best method of combating stain.
Ultimately, I suggest shorter and smaller log piles at the mill and sorting by grade and age. This strategy will give sufficient runtimes at the mill to lessen the impact of species change-overs while maintaining a “first in – first out” inventory.
Dip chemicals are a very good tool to utilize when the time period from sawing to stacking or yarding, is an issue, it is not the solution for log stain. Log stain cannot be reversed once it has begun. Bottom line . . . saw the logs before they have an opportunity to stain, start the “controlled” drying process on the lumber as soon as possible and dip when needed to control the stain.
As always, I stand at the ready to answer your lumber grading questions. Contact me at [email protected] or at 901-399-7551 or send me your questions on Facebook during Live with the Chief.