When I teach beginners, one of the most common phrases I hear is, “I cannot get this (insert tool name) to work. What’s wrong?”
They hand the tool to me and the fun begins.
Though block planes are dirt-simple handplanes, there are some important points about them that are rarely discussed in the literature. Here are the five most common problems I see with students’ block planes.
1. Too tight. Many modern planes have a spinwheel that locks the lever cap to the body of the tool. Most students have this cranked to the point where it could crush a titanium walnut. Not only does this make the tool difficult to use, it also can distort the sole. I’ve seen block planes that have a bump behind the mouth because of a too-tight spinwheel.
So how tight should it be? Looser than you think. It’s a balance: You should be able to adjust the iron with ease, and the iron should not move during normal planing operations. With my block plane, I rotate the spinwheel about three hours after feeling resistance. So lighten up, Francis.
2. Trouble at the back of the mouth, part 1. After a dozen beefy strokes, I think it’s a good idea to clear any dust in the pocket between the iron and the body of the tool. I’ve seen many planes where this area is packed with so much dust that the plane cannot cut consistently (technically, they have violated the clearance angle of the tool, but I want to talk about the clearance angle as much as I was to talk about politics, religion and infected boils).
To clear the dust, I run my fingernail along the back of the throat, staying clear of the cutting edge.
3. Trouble at the back of the mouth, part 2. The other problem with block planes occurs after five or six sharpenings. With a block plane, it is the flat back of the iron that takes most of the abuse (wonks call it the “wear bevel”). After a number of sharpenings, the wear bevel becomes pronounced and you cannot polish at the tip of the back of the tool.
The result: poor edge life and a crappy surface finish.
The solution: Sharpen your block planes using the ruler trick, which polishes the wear bevel. Problem solved.
4. A dinged sole. No matter how sharp the iron is, the wood will look like garbage if the sole has any dings. Block planes take a lot of abuse, so it’s common to see the rim of the sole deformed from hitting other tools on the bench.
A small ding on the sole can ruin an entire carcase side in a few strokes. So I regularly check the sole as I plane. Anything the looks or feels like a ding gets sanded or (in serious cases) filed away with a fine needle file.
5. Plane tracks. If you use the block plane to produce final surfaces you need to tuck the corners of the iron into the plane’s body. That means you should sharpen a curve on the iron, or file the corners round.
— Christopher Schwarz