mild to stainless.

[Com_VC]

Hi,

When putting together my stainless steel water tank I will need to put in some temporary supports to hold it all together which will then later be removed when the tank is finished.

Now what i'm wondering is will it be ok to use mild steel stock for this, welded with stainless steel wire. Reason being I dont have any stainless running around that I can use and cant justify the cost for something like this. I have plenty of mild steel pipe around that I can use.

I think it would be ok to use, but just thought i'd ask. Also is this the way it's done in the industry.

By the way it's 316 grade stainless.

Thanks

[Hotfoot]

I MIG 308/steel with good results for artsy stuff using just my regular MIG wire...the weld rusts, but so does the steel. It welds very nicely.

[Com_VC]

so are you saying it would cause the stainless to rust/contaminate etc?

[weldgault]

Yes, carbon wire will rust on stainless. John

[Com_VC]

I know mild steel wire will rust.

I'll be using stainless wire to tack the mild steel supports to the stainless sheets. The mild steel supports will then be removed and all tacks grinded back etc.

[FWI]

I was always taught to never bond stainless with mild and in fact never sit stainless on mild horses even without cardboard or junk scrap stainless between your mild steel and your stainless, while welding. Don't know if that right but that what I was taught from a couple old pipeliners.

[hankj]

I've welded a bit of mild to SS. The bead will rust if you use mild steel filler, but it will not rust if you use stainless wire.

Never heard the old wives tale that FWI mentioned. I've had hunks of scrap mild and stainless steel in the same drum for years. The rust from the mild scraps get rubbed off on the SS, but it cleans right up.

Hank

[The_Beave]

FWi is correct, but it depends on what your ultimate goal is. There are many specificatins for welding stainless that specifically prohibit even using paint markers that are not certified for use on SS as there could be chemicals in the paint that can lead to cracking under certain conditions. I have also seen fingerprints rusted onto SS headers because the oils from the weldor's fingers contained enough of whatever to cause the SS to rust when the metal heated up.

If you are going to weld 3-series SS to mild, 308 is usually the recomended filler metal choice as it contains a higher nickle and chromium content to offset the lack of those alloying elements in the mild steel, and it will help prevent cooling cracks from forming in the welds.

[latunguley]

I was always taught to never bond stainless with mild and in fact never sit stainless on mild horses even without cardboard or junk scrap stainless between your mild steel and your stainless, while welding. Don't know if that right but that what I was taught from a couple old pipeliners.

Never to weld Stainless with any mild steel but to weld it up with Stainless or to weld up Carbon steel to Stainless with Stainless only as on a stainless tank farm where the piping brackets need not be made of Stainless but to stick to Stainless bracketry.

[Rocky D]

Hi,

When putting together my stainless steel water tank I will need to put in some temporary supports to hold it all together which will then later be removed when the tank is finished.

Now what i'm wondering is will it be ok to use mild steel stock for this, welded with stainless steel wire. Reason being I dont have any stainless running around that I can use and cant justify the cost for something like this. I have plenty of mild steel pipe around that I can use.

I think it would be ok to use, but just thought i'd ask. Also is this the way it's done in the industry.

By the way it's 316 grade stainless.

Thanks

First, let me say that you can weld stainless with mild steel wire...you can, but you may not like the results. It depends on the application. Its just that it is preferred to use stainless wire. In your case, you will use 316L wire...build up your mating surface of the steel with the 316, before you weld the whole thing onto the tank...that way the steel won't come into contact with the tank. We call this process "buttering". Old timers know this for welding cast iron or other dissimilar metals.

[dsweld]

just certed on stainless to steel using 309l which is carbon to stainless wire.i've used all sorts of wire to weld both together but,it doesn't mean i was correct in doing so.i've got a wood splitter that the wedge is ss and the base is steel i used 7018 and its been three years never had trouble.just my nickles worth..

[gfunkatoa]

build up your mating surface of the steel with the 316, before you weld the whole thing onto the tank...that way the steel won't come into contact with the tank. We call this process "buttering". Old timers know this for welding cast iron or other dissimilar metals.

Good point Rocky. If he's gonna grind the tack off anyway, might as well let the tack or "butter" keep the two seperate for the time being.

[bigsteel]

I work in a pressure shop and do LOTS of ss we always cut a ss patch tac it to the tank then weld the carbon to the patch. After we cut the ss patch off the tank. No contamion

[chris.martell]

In my experience with as the patch works well but be careful not to contaminate your as with a grinding wheel that was used on carbon steel

[hockeyguynick]

Just my .02, at work, we weld a lot of SS to CS, welding sleeves onto pipes where the pipe goes through a bulkhead. Navy ships are built to last, so they must be doing something right. Use 308, paint the carbon steel and the weld itself, and you should have no problems.