Thread: Welding thin Stainless

Could probably find the answer somewhere on the net but cant think of how to word it.

I have some thin S/S that I would like to weld it 1.2mm.
I dont have any S/S mig wire or suitable gas.
I have S/S rods 2.5mm.
The item to be welded is not critical.
I would like to know is it possable to do my inital runs with Mild Steel wire and cap with the S/S rods.
This item will be out in the weather and I would like to limit the amount of rust as much as possable.
I dont wish to paint the item.
Thankyou.

Dont use mild steel at all. From experience its a sure fire way to get rust on the weld.

Had a non critical job to do on some stainless pipe. Of course I only had mild rods sitting around at the time. Was expecting rust, sure enough I got it. Cant say I have tried it, but honestly dont see "capping it" with S/S rods will prevent rust.

Dont suppose u can do a test run on some scrap 1.2 mm with your 2.5 S/S rods. Carefully of course. Obviously its not ideal, but if one turns the amps down a bit, it may be enough to get u outta trouble.

Understand your plight. Its nice to have easy access to everything u need in a engineering shop, the rest of us find a way and make do with what we have.

hey pipeclay
my recommendation is try to tack together with your ss rods(goodluck with a 2.5 rod) then once you have the shape, drop it into a ss or alloy welding shop to tig it up. if it is to shape then they will charge bugger all to do it for you. that thickness ss needs to be tig welded.
dont put mild steel any where near it.one you do it then it becomes an inclusion in the metal and will rust very quickly.. it becomes a sacrifical anode so to speak. also it is a bad weak point..
goodluck with you project

Though of doing a bit of scrap,but fairly sure the rods will blow through a little even at 40-50 amps.
Have thought of maybe running a bit of carbon behind where I want to weld and if it does blow through just building the hole up while the carbon is in place.
I can allways dress it up after.

Hi Pipeclay,
I certainly think it may be possible but this is subject to what

• machine you may have
• The joint arrangement of what you are welding -what are you making ?
• The welding tacking & welding sequence
• the type of stainless electrodes you have

A bit more info on those varibles and it is possible that a solution is possible

Cheers
Grahame

Nix to the mild steel on stainless. It will rust ,no doubt about.


What grade of stainless has a bearing on rust susceptability,and also where you live. On the seaboard is salt laden water spray, lotsa rust.
Inland not too bad but will rust eventually.


316L marine grade ,L is for low carbon precisely why you don't want it diluted by bythe carbon steel. 304 Grade onemight usein the yard inland but the same stuff will exhibit rusting by the sea.
I have 304 gate fittings which do ok 3 clicks from the sea.

Grahame

Originally Posted by Grahame Collins

A bit more info on those varibles and it is possible that a solution is possible

You are the expert grahame but all I can say is that after my initial foray using 2mm steel using an arc welder I can't imagine anyone successfully welding 1.2mm steel using 2.5mm rods even on a low current setting without blowing holds left right and center and it being a nightmare all the way around. I guess if you weld or teach welding for years on end you might have a hope but all I know is I wouldn't bother personally even pulling out the welder with 2.5mm rods..

MONTIEEI
Its in technique mate!,
Didn,t grandad tell you theres more than one way to skin a cat.

Stainless steel sucks up the heat that is put into it.
its often a matter of of :

• tacking - lots of them and in the right places-
  
• joint design - cnrs are easier to manage than butt welds
  
• really short bead lengths
  
• waiting for for the work to cool after the short bead or tacks.
  
• a heat sink - a copper backing plate to pull in some of the welding heat.
  
• electrode type + diameter -staincrhome if available-2mm or smaller would be better
  
• Short arc length on the electrode
  

THATS WHY YOU NEED ALL THE FACTS WHEN ATTEMPTING TO SOLVE A PROBLEM

What the Im trying to do is put a couple of hinges on a beer keg.
Material is 304 S/S.
Rods are Satinchrome 316L-17.(2.5)
The welder is an import 200Amp inverter.
The hinges will be the Thickest I can find but will be at least 2mm.

put a couple of self tappers in the hinge, then take it to an alloy fabrication shop with a six pack in your hand. they will tig it p in 5 minutes. then you will be cooking bangers and having a beer with no head ache at all...

i'm with you montee. there is a good bit of practice needed before thin plate is attacked.

your absolutely right grahame it is all possible, but i would look at the effort to hair loss ratio. unless you need the fun of the adventure of course!!

sounds like a great project, lets see the pics.
good luck

It really would depend on the the class quality of the stainless steel however I would not recommend using Mild Steel Wire as it will not take very well to the parent metal

Originally Posted by pipeclay

I have some thin S/S that I would like to weld it 1.2mm.
I dont have any S/S mig wire or suitable gas.
I have S/S rods 2.5mm.
The item to be welded is not critical.
I would like to know is it possable to do my inital runs with Mild Steel wire and cap with the S/S rods.
This item will be out in the weather and I would like to limit the amount of rust as much as possable.
I dont wish to paint the item.
Thankyou.

Originally Posted by pipeclay

What the Im trying to do is put a couple of hinges on a beer keg.
Material is 304 S/S.
Rods are Satinchrome 316L-17.(2.5)
The welder is an import 200Amp inverter.
The hinges will be the Thickest I can find but will be at least 2mm.

aHHH! Exactly what I was hoping for,
On AC welders I would not hold a lot of hope of sucess.
However, inverters are DC, so CHANGE your weld lead connections to electrode postive. This puts the majority of the heat in the rod not the sheet plate.

Over lap and have hinges pulled down flat. NO GAPS. Clamp down so there are no gaps

TRY ON SCRAP FIRST ON THE LOWEST AMPS YOU CAN STRIKE WITH.If this stuffs up ,no loss.

These rods are like low hydrogen (7016) make sure there is no moisture in them.Give them the 100 degree oven treatment if necessary.
Strike arc on scrap, and jump over to tack site.USE A SHORT ARC length

Small short tacks-like equal to 2 match head volumes. A copper back up plate will stop burn through, remember ,stop ,let cool down.There's no hanging around with the arc on this ,strike,jump across with arc running, 1 second of arc deposit and flick away!

4 small tacks are all you need on each hinge,

On the other hand if your practices on the sheet are a complete fubar why not just use stainless steel rivets,quick easy and strong.

Me! I don't give up on things too easy.

Warning ! watch the flux on these rods its remains hot and can pop off staright into your unprotected eyes if your sheild is up. Obviously safety glasses are the go.

Cheers

Grahame

Thanks Grahame,was firstly thinking of rivets but will try on a bit of scrap first,havent got any copper but the carbon block I have should be ok as a substitute I hope.
Thankyou to all for your replies,will let you know how it goes.
Maybe a week or two.

I'm not sure if its the correct way but I was told to hold the rod as horizontal as possible so the arc force is not directed straight through the thin sheet but rather its directed more so into the metal. Same theory as sloped tank amour, a 100mm chunk of plate on a 45° angle is 141mm thick in a straight line.

Originally Posted by DeltaNegative

Same theory as sloped tank amour, a 100mm chunk of plate on a 45° angle is 141mm thick in a straight line.

At the thinness he is dealing with I think it becomes a moot point... It'll help but not greatly.

Originally Posted by pipeclay

Maybe a week or two.

It'll be interesting to see how you go. My money is on rivets unless you invest in smaller SS rods than 2.5mm :lol:. Better yet it might pay to just head over to an exhaust/welding place and pay a few bucks for the guy to do it with a mig and stainless wire rather than screwing the kegs over. I don't think it'll cost you that much for just a couple of hinges. It's why I'm happy I ended up getting a machine capable of mig when I bought my welder. For home I think it's the better solution in terms of versatility and ease.

Hey I don't want to stop anyone from attempting stuff but as long as they go in with realistic expectations rather than expecting miracles, especially if they aren't a pro welder, all is good. I know that I'd have to spend months welding before I had a hope in hell of welding 1.2mm steel with 2.5mm rods and even then it'd be a hail mary and an extremely slow process. If you manage it with 2.5mm rods you have my admiration.