Mig Welding Tip #2 of 19.... For thin metals, use a smaller diameter wire and a 115v machine

MIG welding tips and tricks - MIG welding Tip #2

For thicker metal use a larger wire and maybe even a larger machine. Smaller wire and lower amperage for thinner metal?

What a concept!

For auto body sheet metal repairs, the little 115v mig welders are great. Why is that? Because they are designed to run .023 bare wire. Welders that use .035" bare wire just so they don’t have to change the drive rollers to weld with .035 flux core would be amazed at how much better the machine would weld using .023" bare wire for thin sheet metal repairs. Doesn’t that make sense? But that does not mean you need really thick wire for welding thick metal. When it comes to welding thicker metal, don’t get carried away. For short circuit mig welding,(75/25-ar/co2) .035 is as big as you will ever need.

.045" will just make more spatter and will generally look like Fido's ass. I am serious. I worked for a guy for a while who insisted on .045" bare wire on his mig welding.

He reasoned that he could weld hotter with the bigger wire. (Personally, I have never had an issue with getting hot enough with .035" wire) the .045" wire welded ok until you got to an area where the gun angle changed and then huge BB's would jump out of the puddle and any time saved in welding speed was lost by cleaning up massive weld spatter.

For auto body thin sheet metal work, the best setup is .023 E70s3 bare wire with 75/25 argon/co2 gas. (check out my trick for a better ground clamp here)
Better Ground
Forget about flux core for welding this thin stuff. If you are in the market for a mig welding machine to use for auto body work, get one that is set up for both gas shielding and flux core with different drive rollers for .023 wire and .035 wire.

You can always swap over to flux core for those situations where you are welding something thicker or for welding outdoors.
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