welding MILD STEEL to STAINLESS??

is it realy a good idea??? i did it one time a long time ago with my MIG welder and it seemed to work just fine. it welded just like mild steel usualy does. i want to hear from people who actually KNOW, not speculators (thanks anyway guys for wanting to help). just wondering about welding a mild steel filler tube on a stainless steel gas tank.

thanks

 

Should work fine lots of times at work I use stainless rod to weld tool steel to cold rold or tool steel to tool steel. so welding stainless to mild steel should be fine.


bret

 

Well, i've done it several time's installing custom exhaust at the shop. Guy's would buy aftermarket aluminized 'cat back' systems with the stainless tip's and bring them to me to install.
I only did it when they asked for them to be welded rather than using clamps.

I've never had one brake due to poor weld.

I just tell them they need to coat the welded area with something or it will rust..

 

get a lot of fusion at low temp and it should be fine.

 

ive welded stainless bungs to a many cold rolled tanks with no problems what so ever. as a matter of fact, the tank in my ltd III has a stainless bung in it and has logged about 2000 miles.

 

should have read closer. if you're using MIG, no worries.

 

i thought it would work fine. the one thing i did was weld a mild steel plate to some stainless tubing (like 5" diameter) to make front air bag brackets for a 1 ton dually crew cab ! it seemed to hold up fine .

so it is just the cosmetic issue i need to worry about??

thanks for the input guys

 

why not a stainless filler neck,? you could get the whole thing made in stainless also,

other than than that i would say a choice between 309H and 316LSI a silicone wire better weld,in my opinion, also just a regular CO and argon mix 98 and 2 percent. or
you can use 90 argon 10 helium AG 90 stuff if you want, but turn up the regulator you want a good atmosphere to cover the stainless weld, it will be a good and strong weld

 

we're looking for some sort of cool old filler neck and cap to attach to this tank and most ones i've found are mild steel (or galvanized). not many are stainless, at least not any i have found yet, but i'm still lookin.

 

http://www.rickshotrodshop.com/accessories.htm

what does this one look like?,

you can also buy a filler neck in most any size and shape from the tank maker for milk and food products, all with differnt caps according to the need, hit up a few of those sites

 

this "tank" was made by Strohs brewing!!

 

haha

 

I thought I read somewhere about there being issues with the different expansion rates on the two different metal? Or maybe it was a dream?

 

this is a low dough project for a 16 year old. i don't think a $50 gas cap is in the budget.

 

"i want to hear from people who actually KNOW, not speculators (thanks anyway guys for wanting to help). "

 

I've got a fancy diploma on my wall from FVTC in metal fab/welding that took me two years to earn, so I know for sure. Yes, you can do it. At the fab shop I used to work at, we had a particular filler rod that we used to TIG the stainless to mild steel. If you're going to use a MIG welder I personally would suggest using the wire and gas for stainless, and weld it like you were welding stainless. You can weld it with the mild steel wire but it will rust, you'll need to get something on it to coat it. Mild steel only differs from stainless in that stainless has a relatively small percentage of nickel and chromium in it, so expansion rates would only come into play in extreme conditions. A gas filler neck certainly isn't an extreme condition. Any other questions feel free to ask, I can even dig out my AWS manual if you need something REALLY specific.

 

squablow def knows what hes talkin about, i did exhaust work for about a year at a performance VW Porche shop. used TIG for most applications, but MIG for some hangers, i always used stainless wire and gas mix to do it and never had an issue. and since theres not a big heat transfer in the tank, i would hope, u shouldnt have a problem. just coat it when ur done and you'll be golden.

 

Should be no drama....Tig if possible using 316 filler rod....or if Mig is the only option see if you can get your hands on some 316 wire....and the weld should be "backed" in some way ...either purged or with a backing plate of some kind....either Ally or copper....if not "backed" it will rust up on the inside quite quickly as well

 

What Bones said, we do it all the time at work. Clean both with scotch brite, treat as though it were all SS. Fill the tank with argon.

 

just weld it.

 

I work for an exhuast supplier to the OEMs. We weld literally hundreds of thousands of cold rolled rods/flanges to stainless pipes every year...

 

HEY, another Michigan guy. how are ya?? where do you work??

thank you EVERYONE for all the input. i guess it is ok to do , i thought so but i thought it better to ask first.

 

It will rust the tank.
Don't do it unless you intend to replace it in a couple of years.

 

My Anheuser-Busch tank on the back of my bucket is stainless steeel and I welded galvanized fittings in it with 316 rod(stick) and have had it on the road for four years and nary a leak.