Q: I am sending you several samples of Eastern white pine lumber. These pieces have a small erratic line running across the grain (that is, from edge to edge across the face of the lumber). Sometimes we might see two or three lines in an individual piece. In a wide piece, they may only run 6 or 8 inches before disappearing. Can you tell us what this is? We think it is a kiln problem.
A: The phenomenon that you describe is rarely seen, but does occur in softwoods and will often be common in trees from a small geographic area. What has likely happened is that there was an excessive amount of snow one winter. The excessive weight on the tree stem from the snow actually caused the stem to compress so much that the cells broke in compression.
They broke and slipped on top of one another, creating this line. Under 15x magnification you can see the failures.
Called compression failure, it is a resource problem. The kiln operator is off the hook on this one. We need to be very concerned about this wood because it is very weak, now that it is essentially broken already. My advice is to toss it into the scrap bin.
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