It can be done, right? Do I need a special type of wire? If not will a certain wire be better?

I am fabricating my own downpipe/dumptube. I read that you are supposed to use 308 filler rod for mating 304 to 304. I'm hoping thats not the only thing you can use.

 

per my manual with my miller, you need stainless wire and tri-mix gas (90% He, 7.5% Ar & 2.5% CO2) vs. the normal 75% Ar and 25% CO2.

i'm curious too because i have some minor work to do in stainless and would rather not have to buy the special gas for doing three or four 3" welds for my cold air intake.

how important is the special gas?

 

See we just use straight co2 with our mig welders. We use em to weld steel to stainless and it works fine. We also weld stainless with it, not the 304, but some type. I am also curious as to what gases to run.

 

you need to use trimix and the proper stainless wire. If you use a mild steel wire it will rust and since you are using stainless to begin with that would kind of suck wouldnt it?

I've used straight argon too btw. Why? because I already have it for the tig and I'm to damn lazy to go get another bottle

 

So I'm going to need 304 stainless wire? Only thing i can find online is 308 and up. Will that work? And I should be able to get the 90% He, 7.5% Ar & 2.5% CO2 mix at my local welded supply, right? Does it come in one bottle? Sorry for all the questions, I'm a welding newb.

 

yes you use 308 wire and the gas comes premixed in one bottle.

 

Awesome, thanks for the help.

 

I use 97% argon and 3% co2 for stainless MIG.


Modified by Bailhatch at 10:39 AM 2/26/2006

 

I used the same wire and gas as my reg mig 75/25. Oh **** my welds might rust? I guess I'll use that $200+ that i saved from not buying another bottle with the tri-mix and the stainless wire and put it towards coating

Seriously tho, i'm no expert but what strength difference would there be from tri-mix and 304/308 wire and 75/25 and reg wire?

 

The carbon dioxide probably causes embrittlement of the weld.

I've used 308 wire and 75/25 gaas in a MIG on 304 stainless though. Doesn't weld very nice, but it hasn't failed yet.

 

Yea it looks like **** but I have yet to have a weld fail. I had weird stalagtite type things from when I stopped, a few seconds after welding. I'm sure it's not the best way to do it but it seams to work.

 

i use tri mix with SS mig, i tried others the tri makes the weld look much better!!

 

I Used 75%Argon 25%CO2 with ER308lsi wire... they seem to hold up fine.
I had to cut a weld last week to fix a dent and the rust was superficial. inside of the weld was still very stong.