Small wire -vs- larger wire

[malich]

I have a lincoln pro mig 135 and 175. My question is that on some metal sizes when mig welding you can use .25 or .30 size wire to weld the same metal.

Is there an advantage or disadvantage for using one or the other?

I know when welding thin metals it is better to use a thinner wire, but how about 1/8 inch mild steel? I would assume you would have to use more wire with the .25 -vs- .30 other than that is there any difference?

Thanks in advance.

Mike

[DDA52]

Mike
Use the .025 for real thin stuff and the .030 on everything else. The smaller MIGs seem to work better on .030. The .030 seems to perform better than the .035 on heavy with the 175. It uses the current more efficiently I suppose. My 135 likes the .030 much better. As to advantages, you'll waste less wire on heavy stuff and have much better controll on light stuff.