Cutting the Ends of Rough Lumber before Milling
Some shops make a practice of trimming ends before starting to rip, plane, or profile wood, because gravel or other contamination on lumber ends can ruin cutting edges. September 17, 2012
Question
Our milling (mouldings) room operator insists that the ends of rough lumber must be cut off before any milling. He claims the paint or debris on the ends, as it come from the supplier, dulls the cutters. In 35 years in woodworking I have never heard this. Seems like a waste of time to me. Is he right or is it a waste of time?
Forum Responses
(Solid Wood Machining Forum)
From contributor D:
If you or your vendors have gravel yards, then it is likely that grit gets into the ends. A simple examination of the bunks of lumber will tell you if this is a problem. Do not let lumber touch the floor or ground at any time. It doesn't take much to make a nick.
From contributor J:
The shop I used to work for did the same thing for the same reason. I still do the same in my shop, about an inch off both ends. For me it takes very little extra time, as I cut most of my stock to shorter lengths before milling when possible anyway. I guess you would have to weigh the time to cut the ends versus the time to pull and sharpen the blades if you hit a piece of gravel, to see if it makes sense for you.
From contributor O:
I always had my helper inspect the lumber piles before milling, or I would do it myself. He should also be looking at all sides of the board before he feeds it in the moulder, paying special attention to staples, or debris. I can't tell you how many times I have spotted stones smushed into the top of the board that would have trashed a knife. A good machine feeder should be able to do this easily - they develop an eye for proper feeding techniques.
The main reason for cutting the ends of lumber before milling is that moulders require square ends to maximize the quality of the product being produced. This allows the ends of the boards to be truly butted to each other, helping to prevent issues such as snipe. Paint by itself on the ends of the board won't really hurt the knives.
From contributor N:
The pigments and binders in paint are abrasive. If there is enough paint to have a big effect on your knives, I don't know.
From contributor A:
The end coating is a waxy substance to keep the ends of the boards from checking during the drying process in the kiln. It seals it. It does not hurt the knives at all. There may be other issues that he might be worried about.
From contributor C:
Paints have metallic components similar to some honing stones, so these can affect the edge of the steel.
