It is super easy and quick to sharpen a card scraper and you only need two tools. A File and a Burnisher. Oh, what’s a Card Scraper you ask? Its nothing more than a .032” thick piece of High-Speed Steel about 3” wide and 6” long. It is used to scrape and smooth a wood (or any) surface. When sharpened correctly will peel off a .002”- .003” thick shaving from even squirrelly grain. The Scraper works by creating very sharp burr along the edge. That burr is what cuts the wood.
So how do you accomplish this miracle? You begin with an 8” fine cut smoothing Mill File (Swiss pattern if you can get it). You start by jointing both long edges of the tool.
Jointing is just the process of filing the edge flat and square. It does three things. First it straightens the edge and squares it to the side. Second, it removes the crown previous burnishing created. Third it removes the work-hardened material on the edge, also caused by burnishing. This exposes the softer steel in preparation for the next sharpening. To joint the edge, pinch the file and use your finger or knuckle as a guide. Your thumb will provide downward pressure. Ten or so long strokes will true the edge.
Once you have jointed the edge and it is square to the face you need to remove any residual burrs along the face. Here you hold the file flat against the Scraper and file off any high spots. This only takes a few strokes on each side.
<<QUICK TIP: Files only cut on the forward stroke. To keep from dulling the file lift it instead of dragging it backwards. >>
At this point you will see a number of folks hit the edge and flat on a stone or diamond plate. This step is not really necessary unless you have a bad or coarse file. It really doesn’t improve the edge.
Now we are ready to sharpen. Lock your Card firmly in a vise. Grab your burnisher and burnish the edge with 15-20 strokes. Use very firm pressure and keep the burnisher flat on the edge.
<QUICK TIP: No vise? Clamp the Card between two pieces of wood about 3/4”x 1-1/2” x 8”.>
Next, lay the Card flat on your bench near the edge. With the burnisher 5-10 degrees off the flat and a very firm downward pressure burnish the edge. Burnish 20-30 strokes. Flip it over and repeat. This step draws an initial burr forming a shallow “U” along the edge. Similar to a hollow ground hockey skate. The more pressure and more strokes the deeper the burr. Too much however and the final edge will be overworked and chip and crumble.
Now were are going to tun the edge. Reposition your Card in the vise and burnish the edge flat with about 15- 20 strokes. Keep the burnisher flat on the edge with a firm pressure. This takes that “U” shape and makes it more of a “T” We still have a bit more work to do however. We want the edge to look more like an upside down “J”. That curled burr is our cutting edge.
So, angle your burnisher about 5 degrees and burnish 15-20 times each side. Do it one more time at about 10 degrees.
YOU ARE DONE!! Congratulations – let’s test it.
Nice curls off walnut. That is satisfying!
Check out my video here
And if you need a set of Scrapers and Burnishing Tool try this Crown 375 & 377 Scraper Burnisher and 2 Piece Cabinet Scraper Set (it’s an affiliate link)
