Why can’t I get Dad’s bench plane to work?
I can’t count the number of times I have been asked by friends, acquaintances and customers to examine a bench plane that “just won’t work”. Typically, one of two statements follows the request: “I remember my Dad using this plane for years. I just got it out of the box in the basement, sharpened up the blade on the grinder, polished it, but it just won’t cut right.” or; “Dad never could get this thing to work, even after he’d sharpened it on the grinder. He said it was cheap and that he had just bought it to trim a door that was sticking. He put it in a box in the basement and wound up buying a belt sander to do the job.”
More often than not, I find that “someone” has ground the primary bevel at an angle greater than the bedding angle of the plane. While you can get away with this on a block plane (bevel up), it just won’t work on a bench plane (bevel down). When the primary bevel angle is equal to or higher than the bedding angle, the iron can never be engaged in the cut. So, the plane “skitters” along the surface. The user will often set the iron “deeper”, only to find the plane binds completely.
There have been occasions when folks have presented me with a bench plane whose iron appears to have been ground with an acceptable primary bevel. But upon closer inspection, it appears that “someone” honed a secondary bevel that was so high as to eliminate an adequate amount of clearance. Adequate clearance is generally thought to be a minimum of 12 degrees.
The next time someone tells you that his (or her) Dad’s bench plane just won’t work, check the angles, all of the angles.