Do you want to weld stainless steel without gas?
You’ve a MIG welder.
But you’re not ready to weld up that stainless using Tri Mix.
Not if there’s another option.
And anyway it’s not that big a job. Do you really want to go to the trouble of gas?
Can’t you use flux core welding wire and save time that way?
You want to know …
Can You Flux Core Weld Stainless Steel?
You can buy stainless steel flux core wire. You’ll find there are two types.
A gasless flux wire that needs no shielding gas. And one that’s double shielded using shielding gas.
You can buy either flux core wire in type 308L, 309L and 316L stainless steels.
And match them to the stainless steel you’re welding.
Read on to find out more.
Where Do You Find Stainless Steel Flux Core Welding Wire?
Times have moved on and you’ll find this wire at your local welding supplies store.
Then you can order some on-line.
And when you want to jump ahead and order some. Then take a look at this stainless steel flux core wire article here. The article tells you all about them.
What Kind Of Stainless Are You Welding With Flux Core?
You may not realize this but stainless steel comes in different types.
And when you want a weld you can take pride in. It pays to match your flux core stainless filler wire to the stainless steel you’re welding.
So you end up with a good weld.
Stainless steel is stainless because of the Chromium and Nickel added to the steel. These metals give it its special rust resistant features and shine.
Molybdenum is added to those stainless steel used in high acidic areas.
And you may not believe this but stainless steels used for food fit into this class. As do the stainless steels used in chemical manufacture.
300 series stainless steels are the most common. Some are magnetic, some are not.
There are 400 series stainless steels too. And they’re often seen in car exhaust. And the stainless parts of dishwashers and washing machines.
Look to match your stainless steel flux core wire to the stainless steel you’re welding.
Types Of Gasless Stainless Flux Core Welding Wire
Unlike solid stainless steel MIG wire. Gasless stainless steel flux core wire needs no separate tank of shielding gas.
The stainless steel is shielded by the flux in the core of the welding wire.
You can buy;
Type 308L – the L stands for low carbon. Too much carbon in your molten stainless steel causes a world of problems. And something called weld decay. Weld decay is where your stainless steel weld cracks and fails over time.
Type 308L flux core stainless steel wire will weld 300 series stainless steels. Right up to type 308. It’ll also weld type 430 stainless steels.
Type 309L flux core stainless steel wire will also weld all 300 series stainless steels up to type 309. And what you’ll find even better about this wire is that it’ll weld stainless steel to low carbon mild steels.
Type 316L flux core stainless steel wire is the food grade stainless steel. It has Molybdenum in it and is highly acid and corrosion resistant. You weld type 316 stainless steel with this wire.
Types Of Gas Covered Stainless Steel Flux Core Welding Wire
This type of stainless steel is dual shielded. You can also hear it called double shielded.
Your stainless steel is protected by the flux in the core of the wire. And the shielding gas you use.
It welds fast. Lays down the filler metal like a steam train. And produces welds to make you gasp you’re so impressed.
But it’s more expensive to buy. Plus you need gas tank and regulator.
But you don’t need Tri Mix gas to weld with it. These wires will support 100% Carbon Dioxide shielding gas. And some support high Argon Oxygen mixes.
You can buy …
Type 308L – for flux core welding 300 series stainless steel up to type 308.
Type 309L – for flux core welding 300 series stainless steel up to type 309. And like the gasless flux core wire. This is the gas covered wire you use for welding stainless steel to mild steel.
Type 316L – you use for food grade 316 stainless steels.
Can You Flux Core Weld Stainless Steel With Mild Steel Flux Core Wire?
You may well be thinking of this twist.
For a speedy welding solution.
Using flux core wire made for mild steel to weld stainless steel.
Particularly if you’ve a lower powered gasless flux core only welder.
Because on those welders you typically can’t change the polarity. And you’ll need the reverse polarity to weld flux core stainless welding wire.
So can you?
The answer is yes you can.
But you may not want to when you hear about the issues.
Stainless steel is steel with special properties.
Stainless steel is used on stuff that needs to live outside.
Things that are stainless because the shiny look is what’s wanted.
Things you don’t want rusting.
Stainless steel is used to stop staining and attack from acids. … Like the ones found in foods for example.
The big but is.
Welding stainless steel with mild steel flux core wire will give you a weld that rusts.
And your flux core welder must be capable of outputting at least 90 Amp.
To melt your stainless steel and your mild steel flux core welding wire.
But where you don’t care about the look of your stainless steel.
Or it rusting. And your weld cracking.
Or you’re prepared to paint over the mild steel flux core weld with an anti rust or rust resistant coating.
But bear in mind the two metals have different melting points.
And the flux in the mild steel flux core wire isn’t designed for shielding stainless steel. So weld decay and cracking is possible.
If you’re fine with all that then go ahead.
After all stainless steel is just steel with special properties.
About Bill Byers
I started welding at 27 and now have over 20 years on the job experience. I MIG, TIG and flux core weld. Even done a bit of Blacksmithing in my time.
I enjoy helping novice welders find their feet.
In my spare time you’ll find me enjoying a game of football.
And on the odd weekend paying a round of golf badly. Just duck when you see a golf club in my hand.