The most precise tool for cutting shapes out of sheet metal is the plasma cutter. A plasma cutter yields a small precise kerf (width of the cut) and will cut any electrically conductive metal (aluminum, copper, brass or stainless steel). It is able to achieve a smooth, steady cut with the use of a hand-held torch and an air compressor. In addition to cutting straight clean lines, a plasma cutter can gouge, pierce, bevel, cut holes and trace shapes in metal.
Instructions
1. Make a cardboard template of the shape you wish to cut.
2. Place the shape template on the sheet metal and trace it with soapstone.
3. Place the drag shield (the tip of the cutting apparatus) on the metal at the place you wish to begin cutting. Make sure the arc is directed straight down.
4. Press the trigger. Allow two seconds of preflow air before the pilot arc starts. Move the torch across the metal at a consistent speed once the arc starts.
5. Adjust the speed so the cutting sparks go through the metal and out the bottom of the cut. If you don not see sparks, you are not penetrating the metal.
6. Achieve a finer cut by holding the tip of the torch about 1/8 inch from the surface of the work piece. The closer the torch is to the metal the finer the cut will be, and you will get a wider cut if you raise it away from the metal.
7. Pause briefly at the end of the cut to sever the metal shape from the rest of the sheet.