Coated Stock’s Impact on Planer

Q: I have several board feet of knotty pine that was removed from a room renovation. This has what appears to be some sort of poly or gloss coating with some pigment. I’d like to take that finish off as it’s not in my style. I could reuse these boards for other projects if I could accomplish this. So I have a Delta 12-in. portable planer. How badly will I mess this thing up if I try to reduce the stock from 3/4 in. to around 5/8 in.?

Chris Marshall: At worst, the old finish will dull your knives some, but if all you have are a few board feet to plane, I wouldn’t worry about it. I would run them through my planer, double-checking for hidden nails first. If you’re really concerned about those knives, put on a good quality dust respirator, take the boards outside, and remove the old finish with a belt sander. Blow off all the residual grit, and then plane down the bare wood as usual.

Rob Johnstone: If you get all the nails out of the wood, the knots in the pine are more likely to dull your knives than the finish. Knots can be exceedingly hard, especially in old lumber. And they can take the edge off of a planer knife in no time. But truth be told, your options are sand off the finish … which will clog up some belts … or use your planer or jointer, which will dull up some knives. You’re going to have to change your planer knives sometime, so my recommendation is use the planer, because I hate to sand. I actually have two planers in my shop, and only do the sketchy work on one of them. (If I am afraid that the lumber will be hard on the machine, I use my benchtop planer whose blades are easiest to change.) OK, I hear you, Chris … “Two planers, Rob! Now you are just showing off!”

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