A less expensive torch upgrade is swapping the standard collet body for a gas lens (right). In a standard collet body, the shielding gas passes through the holes on the side of the body and out of the nozzle. Because of the shape and placement of the holes, the gas is turbulent and may not flow evenly across the weld puddle, and if this happens, the ambient air can contaminate your weld. Upgrading to a gas lens greatly eliminates this problem. Think of it as the diffuser in your kitchen water faucet. When diffused, water flows evenly across your hands. Without a diffuser, water swirls out of the faucet and splashes much more than diffused water does. A gas lens kit is not expensive and really does improve the quality of your welds.