The following scene has been repeated so many times during the last seven years that it is beginning to feel like “Groundhog Day” for me.
Woodworker: I can’t turn a hook on a scraper.
Me: Hmm. Let me try it using your burnisher and your scraper.
(Grumbling noises. A grunt. Muttered curses.)
Me: Where did you get this burnisher? It’s not smooth and it’s soft. It won’t even touch this scraper.
Woodworker: I don’t know. I’ve always had it.
(I throw the tool into the garbage can. Woodworkers stands, mouth agape.)
Me: Unless you are going to regrind that into an ice pick, it’s garbage. Let me fetch my Arno.
Despite the fact that we can put a space probe up the blowhole of a distant asteroid, we are still plagued by bad burnishers or too-hard scrapers. Back in the day, when scrapers were made from softer steel (usually scraps from an old handsaw), you could turn a hook with the back of a gouge, a chisel or a really fine screwdriver.
But now that scrapers are much harder – sometimes into the 50s on the Rockwell “C” hardness scale – you need a harder burnisher. I’ve even encountered scrapers in the wild that are much harder than a chisel.
And even if you get a hard burnisher, it might not be smooth enough to do the job. I’ve seen new burnishers that looked like they were dressed with coarse sandpaper. If the burnisher isn’t as smooth as a baby otter’s belly, your hook is is going to be jagged, fragile and worthless.
So if your burnisher is working fine, disregard the remainder of this blog entry. Go back to the shop and sharpen your scrapers. You’re done.
OK, for the rest of you, I recommend the French-made Arno burnisher. It is the only burnisher I have used (and I’ve used them all) that will always turn a hook on all scrapers all the time (yes, even underwater, in a box, with a fox and etc.).
The Arno has two very smooth carbide edges that are mounted in an aluminum handle with a leather pouch. (Use the leather pouch to protect your tool – carbide can get chipped and otherwise mangled.)
I usually use only the rounded edge of the Arno, though I have used the pointed edge on occasion when I am dealing with steel that is crazy-hard.
Of course, the problem might also be your technique. I’ve written a bunch about sharpening scrapers on the Popular Woodworking web site. Check out this video. I also have a DVD that shows you the process in detail that is available in the store.
— Christopher Schwarz