Kevin sometimes mentions the diameter of wire he is using in videos – .023, .024, .030, 0.35 – and, he points out, there are many different wire diameters. How do you know which welding wire to use when? Why change – or not change – what you are currently using to go from, say, .030, which Kevin usually runs in his MIG welders, down to .024? Or go up to .035?

The biggest question: how good is the fit of the two pieces of metal he is welding?

When you have a nice, tight fit on the joint you are trying to make, you can use smaller wire – 1/16th if he is TIG welding, the .024 if he is MIG welding.

If the fit is not good, and he has gaps to fill, he moves up a size to 3/32nd filler wire for TIG welding, and goes to the .030 for MIG welding to provide a little more metal.

If he has a big gap, he goes to 1/8 filler wire for TIG wire, or .035 or .040 for MIG wire. Both provide even more metal to fill the hole.

But what if you don’t have all those different size welding wires available? If all you have is 1/16th for TIG welding or .024 in your MIG welder, but you have a big gap to fill? You turn up your wire speed on the MIG welder. For TIG, you feed the filler wire faster or feed two filler rods at the same time.

What if you only have, say, 1/8th filler rod for TIG but you have a good fit that you wish you had something smaller for? Get a hammer and pound it down, rotating as you tap it to thin the metal.

When you change your welding wire size, don’t forget to also change your MIG gun’s tip size. You might even change the tungsten size for the TIG welder, using a 1/16 for the 1/16th filler rod and 1/8th for the 1/8th welding wire, because you are going to be changing your amperage (or voltage if you’re using a MIG welder) to get enough power to melt the bigger wire. So make sure your machine is set up to work well with the different thicknesses of wire.

P.S. Don’t miss the end – and give Kevin a hard time!