Millermatic 200

I went home last night all ready to lay down some nice beads. Wrong! My first attemp to Mig weld was a disaster. Every time I pulled the trigger the wire would burn back to the tip and about half the time the wire would kink just after the drive rollers where it enters the gun liner.

Went back to the welding shop for advice and parts. Changed the following:


Different Gas - Pure Argon is for Aluminum, switched to CO2-Argon mix.
Changed the gun liner - too much friction on the wire.
Replaced the driver rollers - trying to drive .030 wire with worn out .035 rollers.
New .035 wire - the old .030 wire had rust spots on it.

What a difference! The picture shows the beads I ran on 1/8 inch with almost no practice. Ignore the one where I burned through. I'm getting some popping and spatter when I first start to weld, but once it gets going, it welds very nice. I must say, it's nice not to have to chip off the slag.

I'm waiting for .023 drive rollers from Miller. Once they come in I will switch to .023 wire and see if I can weld 20 gauge sheet metal without burning through.

I also have a leak in the regulator at the bottom. Took it apart and put it back together and now it leaks a lot less. Seems to be coming from some sort of spring loaded pressure releaf valve. Maybe that's to protect the welder from too much pressure? It only leaks when I'm not welding. After I release the trigger, it takes a seconds or two and then it starts leaking.