MIg and arc

[say]

Hi all
My question is this and please be gentle for a newbie
I was a panel beater/ painter for some years and used mig welder for body repairs
Very rarely used an arc welder
Can you please tell me if you had 160 mig and 160 arc why would the arc do thicker metal, i have been reading the forums and members suggest arc for thicker metals, or is it simply they don't have a powerful enough mig

Thanks

 

[Bill Edwards]

If a MIG isn't powerful enough for the thickness of metal you get a 'cold' weld with no penetration, though it can look deceptively OK on the surface. You seem to need more amps with MIG than with stick for the same thickness of steel. A 160a MIG is at the limit with 6mm steel.

With stick welding you can, within reason, weld just about anything with lowish amps. Cold welds tend not to be an issue and you can keep building it up with more runs as needed. A 160a welder is quite capable of welding inch thick metal. The only downside really on thick metal with low amps is the amount of time it takes to burn lots of thin rods. And if a weld looks good or bad then generally that's what it is.

 

[Wendelspanswick]

My understanding is that for the given output from the welder the electrode is a bigger diameter with arc.