Our series of articles focusing on tools looks at how to use your saw.
One of the first things you will have learnt on a silversmithing course is how to use a saw, including fitting the blade. So here’s a reminder of what to do.
A piercing or jewellers saw is used to cut sheet metal such as silver, copper or brass. This type of saw can be used to cut everything from a straight line to complex shapes with multiple piercings.
The saw has 3 component parts, a frame for holding the saw blade, a handle for gripping the saw and the blade which is held in place by 2 clamps, one at the top and one at the bottom of the frame with a further screw at the back of the frame to hold the blade at the correct tension.
It’s worth mentioning that the quality of your saw frame will greatly influence the accuracy of your sawing. Cheap frames can bend, the clamps can become loose and the blade can twist. If you find yourself sawing a perfect diagonal line, this may be because your blade is twisted; it may also be because your saw frame is not square, all difficulties associated with a poor quality saw.
To fit the blade:
Gently rest the handle onto the upper part of your abdomen so that the frame faces away from you and rest the frame in the bench pin. You may have to adjust your seating position to achieve this.
Unscrew the clamps at the top and bottom of the frame ready to insert the blade. The back screw will already be loose at this stage.
Take told of your blade, to make sure that the teeth are facing you run your finger up the length of it. You should be able to feel the sharpness of the teeth against your skin. If there is no resistance, then you have it either upside down, back to front or both!
There is a blank section at the top and bottom of the blade with no teeth. These ends should be inserted into the clamps at the top and bottom of the saw frame, approximately 1cm will be sufficient, and the clamps are then tightened to hold the blade in position.
Apply pressure to the bottom end of the back of the saw frame and tighten the screw to put tension on the blade. Tapping on the bench is a good way to achieve this.
Pluck the blade like a guitar string and if it makes a pleasant twang sound then you have the correct tension to begin sawing. Apply beeswax to lubricate the blade.
It is important that you sit in the correct position with your chest level with the metal. This will reduce fatigue in your hands, wrist, neck and shoulders and reduce the chances of snapping your saw blade by giving you more control over the saw.
Draw the saw gently up and down the metal ensuring that you hold the saw so that the blade remains vertical to your metal and that you do not force the saw forward. Again, this will cause your blade to snap. The teeth of the blade will bite into the metal and do all the work for you, all you need to do is guide it in the direction you want it to go.
Use the bench pin to support your metal. If it is well supported by the bench pin, the metal will not move and the chances of snapping your blade are reduced.
To change direction, move the metal not the direction of your sawing. You should always be sawing away from you. Gently move the metal as you continue to saw until you have turned the piece to the direction you want your saw to be going.
If you want to turn a sharp corner, saw up and down on the spot as you turn the metal through the degrees necessary to change direction before going forward again.
If your blade gets stuck, gently reverse or let go of the metal, so the blade loosens, then carry on forward again.
Remember to keep your fingers out of the way of your blade, saw blade cuts hurt and bleed a lot!
Don’t be surprised if your blade breaks, even if you are following all the advice. Despite cutting through metal, blades are fragile things and break with great frequency, even for the most experienced silversmith but with practice you will break fewer.
Saw blades come in a variety of different sizes. The size of the blade is determined by the number of teeth per inch, the more teeth, the finer the blade. As a general rule you should choose a blade size that ensures that you have at least 3 teeth on the metal at all times.