I've noticed several posts of people new to MIG welding post their coupon pictures up and ask for advice so I figured I would make a thread for all of us out there that need a professional opinion.

I'll start off with a picture of my weld.

Do you guys think it penetrated enough ? also is it bad that the welds look like their stacked in circles ' stack of dimes' ?

 

I just went and practiced some more. Any opinions. I'm using 100% c02



Is this how mig welds have to look ?

 

That last pic is of a GMAW weld in spray transfer mode. You are not using spray transfer mode. You want a weld that looks that consistent however. You should also use C25 (75% Ar 25% CO2) gas when welding mild steel and ER70S-6 wire which you are probably using.

 

i agree, use the 75 25 gas mix.
u can also try pausing on the sides a little for
good tie-in at the edges (toes of the weld)
and strive for a weld thats neither convex or concave
like the samples in your last pic (except u would have a
slight ripple effect which is normal for "short circuit" mig).

 

This was mine after a little practice

 

CBURKE your welds look much better!!!