Eventually my tip got goobered up with spatter until it looked kind of like this diagram. You're not supposed to be able to weld dissimilar metals without flux, but that stuff was ON THERE.
I figured it was time to get some spares.
I got some spare tips to match the wire, $3.50 for a pack of 5.
And a couple of cups for $3.80 each
. They looked about right and I got lucky. They fit my gun perfectly. Probably it's "TWECO" compatible. That's the gun everyone uses. Does anyone have facts on this?
I sprayed some welding anti-spatter spray on the tip to keep it clean. The machinists didn't know what was in it so I looked it up. Ours might be phosgene-based, but apparently veggie lecithin works great.
Get some at your nearest healthfood store, or get a spraycan of "PAM" antistick cooking spray at the grocer's.
There are a lot of good welding forums, here are excerpts from a post by "chipmaker"
04-19-2005, 08:41 PM
"...If your looking for a good anti spatter spray get some spray PAM, the same stuff the wife uses in the kitchen to keep stuff from sticking in her pans. It works fine, and is dirt cheap, and if you get the buttered flavored stuff it smells great when welding.
I have run stainless steel safety wire i mine to weld up stainless and it works fine.........no need to buy expensive stainless MIG wire, unless your doing spec work and lots of it. Aluminum wire is iffy in a lot of these smaller mig units, and usually requires a special teflon liner and a different feed roller to work right, but I have pushed aluminum wire through mine as long as the hose / cable was in a pretty straight line using the standard liner and feed roller. A spool gun works best with aluminum wire, so don;t get disturbed if you try it on aluminum and its ot as easy as steel and you get jams etc.......alum wire on a smaller MIG is like that.......it can be done, but not as easy as a larger unit handles it with a spool gun. ...
Some good wire that is well suited to home and farm use is AWS class ER70S-6. Dirt, rust and paint is a big problem with MIG, as MIG likes relatively clean materials, and this ER70S-6 wire handles materials that are not real clean better than any other class of wire. Lots of companies make it, so just look for wire meeting meeting AWS spec ER70S-6"