Transform an Old File into a DIY Burnisher
More on Card Scrapers
How to Sharpen a Card Scraper
Mastering the Card Scraper
The Scraper Can Replace a Stack of Sandpaper
I got my first card scraper five or six years ago in a hardware store, and was excited to get home, grab a gnarly piece of cherry to turn into a pile of fine, fluffy shavings. (That, and I really wanted to reduce my reliance on my palm sander.)
My excitement didn’t last very long – it was clear almost immediately that I’d bought a dud. I threw it in the bottom of my toolbox and forgot about it. Over the next few years, as my interest in woodworking grew, I came to acknowledge that I, not the scraper, was the dud in the relationship (I was incredulous at first; I had to buy a couple more, from different vendors, to confirm this).
Even as I improved at sharpening generally, I could never get my scrapers to perform as advertised. When I tried to turn a burr at 5 or 10 degrees I couldn’t get one at all. Using my circular burnisher, I’d bear down as hard as I could, but I didn’t know what I was supposed to be seeing or feeling (besides the turned burr itself) to tell me I was doing it right. At best, I was still producing dust.
I made myself a new burnisher out of an old, spent triangular file. click to enlarge
I started to think maybe I was making everything a lot harder than it had to be. Eventually, I decided to take a minimalist approach. I made myself a new burnisher out of an old, spent triangular file. I used my stationary belt sander, with an 80-grit belt, to remove the teeth and round over the corners, then a 120 belt to remove the scratches. When it started to get hot, I dunked it in water, then turned it over. Next, I went quickly from 220 to 2000 by hand and finally polished it on a buffing wheel. It took me about an hour altogether. I kept one corner pretty sharp, rounded over the second, and really rounded over the third, giving me four options (versus the round burnisher, which only has one).
Once you have a burnisher you’re happy with, you can turn a nice burr–as a aggressive or delicate as you want–with just a couple of strokes. I did some experimenting and found that using the roundest corner of my shop-made burnisher works great. For a fool-proof technique on turning a burr using chairmaker Brian Boggs’ slotted block technique, be sure to check out FWW art director Mike Pekovich’s video on the subject.
After becoming frustrated with a traditional burnisher (C) for turning the hook on my card scrapers, I decided to fashion my own out of an old triangular file (R).
After running the three faces over a belt sander, I proceeded to polish the faces to a mirror finish. Presto.
Learn how a simple homemade burnisher helped one woodworker turn his card scraper into a star performer.