Tips on grinding plane irons and chisels

Recently, many woodworkers have turned to white or pink grinding wheels for general purpose grinding. We believe this is a result of the influence of turners who, looking to go from the grinder to the lathe, prefer fine grinding wheels for their finished edge. Grinding plane irons and chisels, however, is or should be a rough shaping operation. We suggest you try a coarse grinding wheel similar to what likely was provided with your grinder before absorbing the expense of these specialty wheels. Chisels and plane irons should be finished with whatever honing techniques the woodworker is comfortable.

A visit to your local machine shop where grinding is a constant activity will reveal that machinists use coarse aluminum oxide grinding wheels for shaping normal tool steel. The white and pink wheels will generally be reserved for surface grinders. Surface grinding is the application for which these specialty wheels were developed and at which they excel. You'll also notice that there are special highly accurate techniques for dressing these specialty wheels.

Well dressed coarse grinding wheels actually generate less heat than even the most expensive fine grinding wheels. A critically important accessory to any grinding system is a wheel dresser. A number of types of wheel dressers are available. Diamond dressers, one of the more expensive options, perform best where some type of accurate feed and contact adjustment are available. It can be easy to peel diamonds from the mountings while free-hand dressing coarse wheels. We advise the woodworker with limited experience to choose the less expensive star wheel dresser. The star wheel dresser is fast, aggressive, and will only cost in the ten dollar range. Carborundum dressing sticks are available but these tend to dull the freshly exposed abrasive.

We feel that a course grinding wheel in the 36 to 46 grit range is best for shaping the bevel on chisels and plane irons. Dressing will both true these wheels and keep the freshly exposed surface in good condition. A wheel that's been trued with the arbor will cut longer because the entire surface is used and the grinder will run smoother. The advantage of a smooth running grinder is that the operator feels more in control and confident.