One of the most frequently asked questions from new turners is, “How often will I have to sharpen?”
Very often. A regular sharpening schedule quickly becomes routine to a turner. You’ll probably want to touch up your tools before at least every other pen. I rarely start turning a bowl without a trip to the grinder. Even those new tools you just bought will probably need sharpening before they are fully ready for use.
Sharpening Methods for Spindle Tools
Sharpening Methods for Bowl Tools
There are also specialty dedicated hollowing tools. For them, the sharpening method varies depending on the shape of the cutting tip. Some require special holding jigs. Some are disposable.
Sharpening System or Not?
Sharpening systems are a matter of personal preference and budget. There is no “right” way to sharpen your tools (but there are plenty of “wrong” ways). As long as your system is capable of quickly putting a fine edge on your tool it will work. Many turners use a standard bench grinder with aluminum oxide wheels (or better). Others prefer more esoteric systems such as the Jet or Tormek. Such high-end systems work very well if you have the budget or already own one. If this is the case you may want to look into special attachments for turning tools.
Bench grinders are one of the more common methods of sharpening, and the least expensive (other than sandpaper or hand stones – both of which can be made to work but are extremely slow and therefore less practicable). Grinders generally come in three flavors: high-speed (3450 RPMs), low-speed (1725 RPMs), and variable-speed. Regardless of what anyone tells you, it doesn’t matter what speed grinder you use for sharpening HSS tools. Any of the above will work just fine.
Another grinder choice you’ll be faced with is wheel size. 8″ grinders are often touted as putting less of a concave on the tool bevel than a 6″ grinder. I always laugh when I hear this. Again, it doesn’t really matter. The wood is not going to know the difference. The best argument for 8″ wheels is that it offers widths up to 1″ giving you a bit more sharpening surface to work with. 6″ wheels are generally 3/4″ wide. Again, the difference is a matter of convenience and personal preference. Either will work just fine.
As mentioned above, aluminum oxide wheels (or better) are well suited for sharpening HSS steel. Wheel color is not important. Wheels between 80 to 120 grit are generally considered good for sharpening. 60 grit wheels (or lower) are best for reshaping but could also be used for sharpening with a light enough touch.
For more information on sharpening various tools, see Jerry Hall’s excellent guide here.