Sure, we all know to keep our handplanes sharp, clean and lubed. But when was the last time you did maintenance on the tool’s mouth and the edges of its sole?
These areas are fragile and take a heap of abuse. Yet little is written about how to regularly maintain them.
Let’s start with the mouth of the tool. The area of the sole right in front of the mouth gets worn away from use. Not decades of use. Usually just a few months of heavy use will cause noticeable wear.
Why do we care? If the sole in front of the mouth isn’t pressing down the wood fibers, then the cut will happen ahead of the tool’s cutting edge. And that’s tear-out.
If the wear is shallow, you can remove it by rubbing the sole on some #220-grit sandpaper affixed to a flat floor tile. (If the wear is deep, you will need to file the front of the mouth, which I will cover in a future entry).
To flatten the sole, paint some red marker on the sole surrounding the mouth. Then rub the sole on the sandpaper until all the color is gone. I usually dress my plane sole every six months, and the dressing can require 5-10 minutes of work.
Once the sole is done, you should bevel the edges of the sole – with sandpaper or a file. Why? The edges of the sole are fragile when they are a sharp corner. They are stronger when they are rounded over. So if your tool has a sole with rounded edges it is much less likely to develop a burr when the plane collides with a fellow tool or a knot. These burrs look like plane tracks on the work and frustrate beginners.
To round over the edges, I tilt the plane 45° and round over the plane’s long edges on the sandpaper (see the photo at the beginning of this entry). Then I file the front and rear of the sole with a fine needle file – these areas of the sole take the most damage – to create a bevel. Then I round over that bevel with some fine sandpaper.
These small efforts make a huge difference. Your plane will produce less tear-out. And it is much more likely to leave a flawless surface behind.
— Christopher Schwarz