Lost Art Press

How to Sharpen a Piercer Bit

Posted on by fitz
Fig. 4.16 Lay the burnisher flat on the cutting face. You only need to work near the bit’s end. It’s not necessary to sharpen all the way up the flute. We usually only sharpen one side, but piercers are made to bore holes both clockwise and counterclockwise. Sharpen the side or sides according to how you will use the tool. Do not touch the outside of the piercer.

The following is excerpted from “Make a Joint Stool from a Tree,” by Jennie Alexander and Peter Follansbee.

Like with any tool, there are a lot of different ways to sharpen piercer bits. Files, stones, burnishers and more. We sharpen them on the inside only. Many different methods will work, including using burnishers, files and stones. The best tool we have found for sharpening these bits is a triangular burnisher. If you can’t find one, then you can take a worn-out triangular file, grind off its teeth and mount it in a handle. Then you can use it as a burnisher to turn the piercer’s edge from the inside.

Mark Atchison, a blacksmith we have worked with for years, has a nice method of getting these bits really sharp. He uses a worn-out round file, and grinds the end of it square and uses it as a burnisher to run down the inside edge of the piercer. Save your old worn-out round files; you can use various-sized burnishers to fit different-sized piercer bits.

Fig. 4.17 All you need to sharpen the piercer bit is a triangular burnisher, like the one shown here mounted in a turned handle. Its steel is hard enough to turn a hook on the piercer’s steel.
Fig. 4.18 This version of sharpening a piercer is not all that different from the previous idea. Blacksmith Mark Atchison pushes the file/burnisher down along the inside of the piercer’s flute. This creates a hook, much like on a cabinet scraper.

6 thoughts on “How to Sharpen a Piercer Bit”

  2. I don’t have any bits like that but if I do get some I can now sharpen them. Thanks

  3. I find my piercer bit doesn’t dull very fast, so I’ve never considered a special tool to sharpen mine. I just wrap a drill bit in some fine wet-dry sandpaper and use that. to sharpen it. The hook is very fine, but I don’t use it all that often, so it’s enough for me.

  4. LAP – THE Font of information! I did not know that you were not supposed to sharpen or hone the outside of the bit – curious – this is labeled a Piercer Bit – is it the same as a spoon bit? (if not what is the difference?)

    1. Look at the last picture. Soup would clearly run out of it, the nose is open. For a spoon bit it is closed. (as I seem to recall).
      There is a lecture by Peter Follansbee and JA on YouTube where they explain the difference. Watch the whole thing, great show!

Comments are closed.