Just want someone to tell me what I,m doing wrong. And what I can do to improve. I,m using a Lincoln Electric MIG with Argon/CO2 mix.

 

Stop welding on tubing.

What is the argon/co2 ratio? I am assuming 75% argon 25% co2 which is not optimal for stainless.

What wire are you using? Size?

Stop welding on tubing.

 

if anything you should be tacking with a MIG, finishing with TIG, or do the entire thing with TIG

plus, your not going to get good penetration if your not back purging. i built my SCH-40 manifold by tacking with stainless mig wire, then back-purging and finishing with TIG

 

I know my welding looks like ***. I blew a hole through it once and covered it(the big lump) Thanks for the advice. Thats what I,m trying to figure out. I,m probably going to pay someone to TIG weld my muffler tips on. I,m going to practice more, too. I

 

And if u really wanted to mig stainless u would need a tri mix (argon, co2 and helium I think) along with stainless wire to keep the properties of stainless and prevent rust.

 

You can (should) mig thin stainless with argon+co2 only, but the co2 is a very low percentage (~2-3%)

 

Welding thin tubing with a 98/2 mix is silly. It always comes out like ***. I don't know why so many people recommend that gas for SC on thin stuff. It's primarily a spray transfer gas. Tri-mix is really easy to run on thin gauge stock.

 

Are you talking argon heavy tri mix or helium heavy?