How to Sharpen and Use a Curved Scraper
Peter Galbert uses a curved card scraper as a shaping tool to fair curves and dial in complex shapes on chair seats
Synopsis: Peter Galbert uses a curved card scraper as a shaping tool to fair curves and dial in complex shapes on chair seats. With the aid of a simple honing jig, he’s able to sharpen a curved scraper quickly and reliably. Here, he shows how to make the jig, how to use it to create a sharp edge, and how to use the scraper once you have reached sharpening perfection.
The card scraper is an indispensable tool in my shop. I was introduced to it as a tool for refining flat surfaces, but I now use it more as a shaping tool to fair curves and dial in complex shapes on chair seats. The soft metal is easy to grind to a curve, and with a simple shopmade honing jig I can maintain a high level of sharpness across the curved edge with speed and repeatability.
The cutting edge of any scraper, straight or curved, is a slightly deformed 90° meeting of the flat face of the tool and the edge. While much is said about “turning the burr,” the real attention should be paid to establishing a perfect right-angle relationship between the face and the edge. If these surfaces meet at a sharp 90° angle, the scraper will take a good shaving even without a burr. Adding a burr improves the cutting action from good to beautiful. But if there is any rounding of the underlying edge, there will be little hope for success, regardless of your efforts with the burnisher.
Another important factor, besides having a sharp corner where the surfaces meet, is the condition of the surfaces. When you joint the edge with a file, you’ll attain the correct geometry, but the edge will have grooves left by…