01-23-2015, 11:45 PM
I set out to do a little welding today on some 20 gauge sheet metal which is right in the wheelhouse for my little 110 volt Miller 140 mig welder. I normally keep it set up with .030" flux core wire for outside/portable usage, so I needed to change it over for use with solid wire. Not feeling up to pulling down a 10 lb. spool from the top shelf in my storage rack, I spied a small 1 lb. spool that someone had given me probably 15 years ago. Campbell Hausfeld .024" ER70S6, probably from a big box store. It was unwrapped and the outer layer of wire was a little crusty, but I thought it would be a good opportunity to use some of it up. 
I didn't want to run the ruff stuff through my mig gun liner so I un-spooled the top layer and trashed it. After getting it loaded up in the welder I had another thought. I never use the "auto set" function on this machine and decided to try it out using this old spool of wire. Using the suggested starting voltage (#3 w/.024" wire) from the door chart was a total failure. Didn't have enough voltage to maintain an arc. I finally got it to run pretty well with the voltage at #4.5 but it was too hot for the thin sheet metal. I knew that the auto set calibration was lacking the first time I tried it when I bought the welder, but it wasn't that bad. It just didn't like the old dirty wire - at all.
So it was back to manual mode where the chart calls out for 3/50 on the knobs. After running a few test beads I settled in on 3.8 for the voltage and about 54-55 on the wire speed. Pretty close, but Miller's starting points always seem to be on the weak side to me. Same way on my Millermatic 185. I'm just patching up some panels on an old snow thrower so these certainly aren't critical welds. Nothing to write home about, but better results than I expected from an old dusty open spool of wire sitting in my basement for years. Have the welds ground down smooth and flush now, and the first coat of primer applied. One panel down, two to go....
I didn't want to run the ruff stuff through my mig gun liner so I un-spooled the top layer and trashed it. After getting it loaded up in the welder I had another thought. I never use the "auto set" function on this machine and decided to try it out using this old spool of wire. Using the suggested starting voltage (#3 w/.024" wire) from the door chart was a total failure. Didn't have enough voltage to maintain an arc. I finally got it to run pretty well with the voltage at #4.5 but it was too hot for the thin sheet metal. I knew that the auto set calibration was lacking the first time I tried it when I bought the welder, but it wasn't that bad. It just didn't like the old dirty wire - at all.
So it was back to manual mode where the chart calls out for 3/50 on the knobs. After running a few test beads I settled in on 3.8 for the voltage and about 54-55 on the wire speed. Pretty close, but Miller's starting points always seem to be on the weak side to me. Same way on my Millermatic 185. I'm just patching up some panels on an old snow thrower so these certainly aren't critical welds. Nothing to write home about, but better results than I expected from an old dusty open spool of wire sitting in my basement for years. Have the welds ground down smooth and flush now, and the first coat of primer applied. One panel down, two to go....
Willie