A chisel

Fig. 5

You will often need to cut off small pieces of wood from a large piece, or cut a tin. The chisel will help you do these things, as well as many other kinds of cutting work.

To make a chisel you will need:

One nail, 15 cm long

Hammer

You will also need a very hard surface to work on. You could use a piece of iron from an old automobile, or any other kind of scrap iron. Sometimes a heavy piece of metal is around the school compound, such as metal that is banged to make a sound calling the pupils together for assembly.

Put the nail on the piece of iron and, with the hammer, hit the pointed end of the nail until it is flattened. The following three diagrams show (A) a 15 cm nail before hammering, (B.) the hammered nail from a top view and (C) the hammered nail from a side view, showing how it has been flattened.

Diagram A

Diagram B

Diagram C

The nail is then cut with a hacksaw blade to get a flat edge. The following diagrams show the angle of cut to be made.

Fig. 6

After cutting, the edge needs to be sharpened by rubbing it against a hard rock. If a hard rock cannot be found, you can buy a small file. After sharpening the edge should look like the one in the following diagram.

Fig. 7

Remember that files are made of metal which will rust easily. Rust destroys the sharp edges on the teeth of the file. A small amount of cooking oil or fat can be put on the file after it is used each time and this will prevent rust.

Most nails you buy will probably be made of soft metal. When you use the chisel it will become damaged or blunted quickly. you can harden the tip by the following procedure. Make a fire and place the end of the nail in the fire, keeping it there until it is glowing red. Then drop it quickly into a tin of cold water. Repeat this procedure several times.

Using the Chisel

The chisel is very useful in shaping wood or cutting holes in wood. When pupils make holes in wood, they usually try to chip out big pieces of wood. It will be easier if they cut only small pieces at a time. This practice will also preserve the chisel. mere will be occasions when you or your pupils will want to chip away part of a piece of wood to get a certain width. Again, chip off small slices at a time until the desired thickness is reached.

Another use for the chisel is the cutting of tins.

Fig. 8

Cutting on a hard surface will damage the point of the chisel. Be sure to place the tin on a wooden surface such as a thick tree branch. When you cut through the tin, the point will go into the wood and the chisel will need to be pulled out before making the next cut.

Remember that the chisel cuts best when it is sharp. Keep a hard stone or file around the classroom and encourage the pupils to use these sharpening tools often.