Step 17: When to replace the wire feed's tip
Most often I use my wire feed welder to weld small pieces together with a spot or a tack. It is easy to point the gun at the exact spot where the weld is to be placed and then pull down the welding hood. An auto-darkening helmet is a tremendous help, and well worth the cost. In time the hole in the tip wears and exactly where the wire will strike the metal when the trigger is pulled becomes less predictable. There will be some problem, anyway, because the welding wire has a natural curve in it from being rolled on the spool. But, when you notice the wire is still less predictable as to where it will strike the metal, it is time to replace the copper tip.
The photo shows a 0.030 inch tip I have retired. I polished the end so the hole is more visible. Notice that it is no longer perfectly round. The welder worked better with a new tip and seemed to have a better arc.