Make sure that the cutting edge is sharp. Dull chisels can be difficult to control and require more effort to do the job. Chip or cut with the blade pointing away from yourself. Keep your hands and body behind the cutting edge.
You can sharpen your chisels on a bench grinder. Your bench grinder must have enough power and the correct type of stone. More importantly, you must use techniques that maintain the correct bevel and avoid overheating the steel in your tool, which can soften the cutting edge.
Types of Chisel
- Flat chisel.
- Cross cut chisel.
- Side cut chisel.
- Round Nose Chisel.
- Diamond point chisel.
- Cow mouth chisel.
Caution: 9 inch (230 mm) angle grinders have been banned on some work sites due to the increased risk of injury. The increased power and size of the unit will cause more severe kickback and gyroscopic effects (i.e. makes the grinder difficult to manoeuvre).
Classification of angles on the basis of their degree measures are given below: Acute Angle: An angle whose measure is more than 0° but less than 90° is called an acute angle. Angles having magnitudes 30°, 40°, 60° are all acute angles.
Note: 9 inch (230 mm) angle grinders have been banned on some work sites due to the increased risk of injury. The increased power and size of the unit will cause more severe kickback and gyroscopic effects (i.e. makes the grinder difficult to manoeuvre).
A spindle roughing gouge turns blanks into cylinders; it can also turn basic shapes, such as tapers. Note that this tool is for spindles only. It is not intended for bowl turning. Any bevel angle from 40°-55° works; so the factory-ground angle is a good starting point.
The best way to tell is by asking the manufacturer of the knife. As a general guide, European/American knives manufactured before 2010 have 20 degree edges while Asian style knives have 15 degree edges.
Wear safety glasses or goggles, or a face shield (with safety glasses or goggles) to protect against flying particles. Gloves, aprons, metatarsal safety boots, hearing protection, and respiratory protection may be required, depending on the work. Ensure the floor around the work area is clean.
Selecting an angle for your knife edge is an important first step in sharpening. Selecting an angle is probably one of the easiest steps in sharpening, once you know the basics. To make it easy, a 20 degree bevel angle is a good starting point. If properly sharpened, the 20 degree angle will work well for most knives.
Chisels have two blade angles. The shallow, long angle which is usually set to 25°, is called the grinding angle as the chisel is ground down to this angle when first made. The second angle (usually 30°) is called the cutting angle and allows for easier sharpening of the chisel itself.
Common Sharpening Angles
| Common Plane Types | Frog Angle | Angle to Sharpen |
|---|
| Bench Plane – Standard Angle | 45º | 25º to 30º |
| Block Plane – Standard Angle | 20º | 25º |
| Block Plane – Low Angle | 12º | 25º |
The diamond stone works so well on coarse work because it cuts aggressively and stays flat. The waterstone is great for putting on the final edge. For example, a coarse/fine diamond stone combined with a very fine 4000/8000 waterstone works well.
If the edge doesn't seem to last long, a higher bevel should help. Unless you are sharpening a skew chisel, you will probably want to ensure that the edge is square to the sides. While it is not difficult to compensate for an out-of-square edge when using a chisel, most woodworkers prefer that the edge be square.
Angle grinders are versatile tools that can grind metal and cut tile, stucco and pavers, rout out mortar, plus they can sand, polish and sharpen. Learn to use an angle grinder to cut tile, mortar and pavers; make quick work of rust and loose paint removal; sharpen blades and cut or grind steel.
The left hand holds the chisel so that the forefinger lies close to the grinding support and under the chisel. The right hand vertically presses the chisel against the wheel in a position directed slightly upwards steadily moving it to and fro. Then, the chisel is sharpened from the other side.
Chisel, cutting tool with a sharpened edge at the end of a metal blade, used—often by driving with a mallet or hammer—in dressing, shaping, or working a solid material such as wood, stone, or metal.
