Sometimes before you can weld you need to be able to remove other material before you can begin. For doing this it's hard to beat plasma cutting. Plasma is an ionized gas that conducts electricity. Plasma is created by adding energy to an electrically neutral gas. In this application the gas is compressed air and the energy is electricity. The more electrical energy added, the hotter the plasma arc becomes. Plasma-arc cutting machines control this powerful energy by constricting the arc and forcing it through a concentrated area called the nozzle. By increasing air pressure and intensifying the arc with higher amperage, the arc becomes hotter and more capable of blasting through thicker metals.
As you can see from this photo, a plasma cutter makes short work of the 1/4-inch thick steel framerail. Plasma provides numerous advantages over other common cutting processes. The plasma process cuts any type of electrically conductive metal including aluminum, copper, brass, and stainless steel. Plasma cutting produces a narrow and more precise cut while sawing or chopping takes a long time and will typically leave a rough edge. Plasma cutting is fast, clean, and leaves a nice straight edge. It also offers gouging and piercing capabilities.