Plasma Cutting Tips Part 5
Improper torch manipulation will result in not only damaged welding consumables, but possibly result in damage to the torch itself from blow back of sparks and dross. Keeping the torch at the right angle and distance from the work piece is essential. When establishing a cut, starting off edge and moving into the metal is the best and least problematic way of starting a cut, with little or no blow back. However, at times a pierce cut is sometimes required. For a plasma cutter, anything over 3/16” should follow This is when most of the damage occurs if correct technique isn't followed. To make a correct pierce cut, locate the side that you wish to discard and angle the torch at a 30-45 degree angle with the tip pointed to the discard side. Start the arc, and then rotate the head vertical as the flame cuts down into the metal, eventually going completely through the metal. This will keep blowback down and sparks and slag away from bouncing back to the tip, preserving your welding consumables. If you use the flat of an angle, where the torch is close to parallel with the work piece, it will be difficult for the pilot arc to transfer, and waste time and consumables until the flame is making enough contact with the metal to quickly transfer the arc. Keeping a proper standoff distance is important as well. Most modern torches can be used to “drag” across the metal under 30 amps or so. Anything over that will cause the consumables to stick to the metal, and the blowback to stick and melt the consumables. Even at 30 amps, or less, consumables do show increased wear over time than ones used with a small standoff. A proper standoff height is typically less than 1/8”, but not less than 1/16”. This is hard to do free hand, without practice, and many torches come equipped with either a standoff or a shielded consumable to allow you to drag the torch on the metal without touching the work itself. But with a little practice, a consistent standoff height can be made free hand.