Stainless steel will be the death of me

[dmanwithwelds]

I have been trying to weld together a stainless steel rail and in 3 days I have 20 ft out of 240 foot done. My setup is millermatic 211 Auto set with MVP wire is ER308L size 0.023. In 11 lb spool. Gas is tri-mix. I am having the hardest time keeping the rail straight and at the angle since it is a rake rail. All the welds are coming out really bad and it is going to need some serious finish work. I don't know what grade ss it is but it is sch 40 size and bends. I also have a millermatic 350p that I could use with the spool gun if that would make a better looking weld. I need some help with this one guys, I love welding but not lately. Any tips or xp with ss would help

[Type]

I've never done any stainless steel work but the shop next door tig welded tons of stainless steel railing not too long ago. I beleive he built small sections then bolt them together somehow. I may be mistaken.

[H80N]

Pics of the welds would be helpful....

BTW .023 is usually used for thinner stuff... like 12 Ga and smaller

[cruizer]

023 is for floor pans, so real thin. How thick is the rake rail?

[Cgotto6]

Do you have welding experience? Do you have pictures of the welds? As others have said, .030 would probably be better suited to your material.

[big mike]

"Gas is tri-mix."
Argon, CO2, oxygen or helium, argon, CO2?

[H80N]

"Gas is tri-mix."
Argon, CO2, oxygen or helium, argon, CO2?

There is some controversy on what is the best gas mix for MIG on stainless...

Here is an old tread on it..

http://www.millerwelds.com/resources/communities/mboard/showthread.php?3538-Tri-mix-gas-for-stainless-steel-MIG-welding

And here is the Praxair gas selection manual...

http://www.prest-o-sales.com/other_links/gases/PDF/ShieldingGases/Manuals/Shielding%20Gas%20Selection%20Manual.pdf

Also...I do hope that you are NOT trying to use the AUTOSET feature on stainless...

[H80N]

Here is the shielding gas cross reference to sort out those zillions of catchy tradenames and figure out the actual gas composition of these mixes...

http://www.aoc.com.mx/biblioteca/tablas_conversion/COMPARATIVO_DE_GASES_DE_PROTECCION.pdf

[big mike]

Argon, CO2, oxygen has more CO2 than is normally recommended for stainless(below 5%)

[H80N]

Tri Mix... Which Tri Mix...???

Argon, CO2, oxygen has more CO2 than is normally recommended for stainless(below 5%)

There are a whole bunch of gas mix recipes.... we won't know which one till he tells us...

if we look at the cross reference and selection manual... the selection is formidable...