Re: Mig Welding Question.
There are a couple of things that will puke up a Mig weld.
1. No, or two little gas. wind is a serious factor too,
make sure you sheild your sheild, the gas must
encapsulate the weld area, untill it cools. That's why
it's best to drag your arc, unless your welding uphill.
Check by listening to the nozzle, gas should be audible.
2. Contaminated material. Oil, Paint, galvanized or any
chemical will flow into the weld and perculate out as it
cools. Ugly! The cleaner the metal, the better the weld.
3. Condensation on the material. If it's near the dewpoint,
Preheat your material, even wiping it off won't cure it.
General note, if your gas is getting low, alot of times we'll go over, turn up the gas, weld alittle and then it goes bad again. That tank holds alot of pressure, but when it gets low, no volume and the regulator works by differential. It'll stairstep untill it's completely empty.
So don't do any structural welds when your tank is getting low. Save your spot welding and sheetmetal, for a nearly empty tank. Thus getting your moneys worth.