So, I’ve seen tons of videos, read more blog posts than I remember, and tried myself many times to follow all the different methods for sharpening a card scraper I’ve found online. After finally getting the hang of it, I wanted to post my simple no-nonsense method so you can all sharpen card scrapers with ease as well.
It’s really quite a bit simpler than people have made it out to be.
1. Unsharpened Card Scraper (If you don’t have this, why read this sharpening guide?)
2. Single Cut Fine Mill File (the kind you probably already have somewhere)
3. Burnishing Rod (Can be bought cheaply across the globe from Fastenal, or you can just use any hardened steel rod you find. Old Printers even have some.)
4. Woodworking Vise
Step 1: Build a ‘Fancy-Pants Sharpening Jig.’
For the scraper to sharpen properly and give you 2 useful cutting edges per sharpened side, you’ll need to square the end. To do this, you need my ‘Fancy-Pants Sharpening Jig.’ Or you could use a steady hand. but we’ll assume you don’t have a steady hand, so on to how to make the jig.
First, take your mill file, and clamp it in your woodworking vise so it’s half above the wood jaws. next, check to make sure it’s square to the top edge of your vice jaw. if not, add some shims until it is. Second, you… Wait. That’s it. You’re done making the jig.
Step 2: Square the Edge.
Next, you need to square the edge of the scraper. To do this, you press the big flat part of the scraper down on your ‘Fancy-Pants Sharpening Jig’ and push the edge into the file, then slide along its length. I’ve included some action shots of this so you can really get a feel for the motion.
Do that a couple times, until the edge is all flat and shiny, and you’re on to step 3. If your scraper is way out of whack, it may take as many as 5 times. If you’re super worried about edge retention and want to spend a lot of time repeating this process with sharpening stones of various grits, other people wrote long complicated guides about that, so you can read theirs. Mine is the easy way, so we’re skipping to Step 3.
Step 3: Flatten the Faces.
Once you’ve got a squared off edge, you need to flatten the faces. To do this, lay the scraper flat on your workbench and slide the burnishing rod back and forth across the edge. You want to try and keep it pretty close to flat for this bit, but it really doesn’t matter if you’re a few degrees out of whack.
The secret to doing this step and the next correctly is this: use about as much pressure as if you were buttering toast.
In the past, I used too much pressure for roughly everything relating to card scrapers, so instead of consolidating a nice edge, I would actually squish it down and round it off. This made my scrapers not do anything, which was frustrating when I saw everyone else making nice curly shavings. Anyways, keep doing Step 3 for a few passes at a time, and check by sliding your thumb up the edge until you can no longer feel a burr.
Once there’s no burr on the big flat face, you’re ready for the final step…
Step 4: The End.
Remember how in Step 3 you just moved the burnisher back and forth and it pushed the burr to the edge? Now you get to push it back. Again, use about as much force as buttering toast. Start out holding it flat-ish, for a pass or two, then angle it slightly (0-15 degrees) to each side for a pass or two.
(Yeah, I used the same picture for both checking to see if there’s not a burr, and checking to see if there is a burr. Either that or I’m really consistent in positioning my hand and camera for the shot. You, as the reader, can decide.)
When you feel a burr on the edges, you won. now you can push the scraper at roughly a 20-30 degree angle with one of these burred edges facing the wood (again, not super hard, more like buttering toast) and you will get fancy shavings like these.
Now you can tell everyone to stop worrying about reading twenty-page blog dissertations on card scraping, and go from dull to sharp in about a minute (including the time it takes to build a ‘Fancy-Pants Sharpening Jig’).
-- -Tim, Salt Lake City, UT, USA