The yellow wheels are mounted on the outside of the grinder and are designed to be used with curved tools like gouges. The 4" diameter wheels can be adapted to any grinder with a 1/2" spindle...
- Replacement wheel for Koch sharpening system
- 4" diameter wheels can be adapted to any grinder with a 1/2" spindle diameter
- Designed to be used with curved tools like gouges
- Used to sharpen carving tools, bench chisels, plane irons or turning tools
Best Carving Tool Sharpening
As a woodworker for 40 years I've owned just about every conceiveable sharpening tool, jig, machine, stone, sandpaper on glass,etc., that exists. The Koch wheels sharpening method was recommended by a couple of pro carvers who's advice I respect. The Koch system is actually so good it's shocking! Woodcraft no longer sells the complete system with grinder but purchase the yellow and green wheels with green paste. The wheels are actually identical but dedicate the green for flat tools(incl V tools) and the yellow for rounded gouges, etc. Red and blue wheels w/ white paste not necessary. Use a slow or vari speed grinder with 1/2" arbor (2,000rpm max). The arbor holes are too tight (German made undersized) so drill them out with a 1/2" bit. You need to take off the side wheel guards and turn the grinder around to the back, as the wheels are meant to turn up and away from you (not down as all traditional grinders do). Fabricate your own tool rest. I used a 5/8" steel bar running horizontal in front of the wheels level w/ center and 5/16" in front. Razor sharp, no burr (really), and lightning fast. I sharpened 28 carving tools including several V tools in 15 minutes and they were sharper than I have ever seen. Used to take most of a day. IMO no better sharpening system exists for carving tools... that's a strong statement, but I stand by it.