How important is the Contact Tip in MIG welding?
Very important. Make sure the gun tip isnt worn out or that weld spatter is not on the tip near the exit hole. The contact tip in the gun should be perfectly round and just a few thousandths larger than the wire itself. Worn tips are typically oval and can cause an erratic arc from the random electrical connection and physical movement of the wire inside the worn tip. Genuine Lincoln contact tips are precisely made from a wear-resistant copper alloy for superior welding performance. If the contact tip enters the molten weld pool, it should be immediately replaced. For most casual welders, a good rule of thumb to assure high quality welding is to change the tip after ever 100 lbs. of wire. Another point to remember about contact tips is that they should always be threaded completely into the gas diffuser and tightened prior to welding to give a smooth flow of welding current. IF THE CONTACT TIP LOOKS QUESTIONABLE, GET A NEW LINCOLN TIP, THREAD IT COMPLETELY INTO THE GAS DIFFUSER AND TIG
