When you’ve damaged stainless steel needing a weld repair.
A local guy quoted you big bucks to TIG weld it.
But you have a welder …
Your local welder supply store is happy to sell you some Tri Mix gas to weld it with. But it’s some huge cylinder. And you’ll never use all that.
And the price they quoted you for the cylinder was way more than you planned on spending.
But you’re wondering …. Do I have to use a tank of gas?
Can you weld stainless steel with flux core wire?
And by that you mean is there stainless steel welding wire you can use without a separate tank of shielding gas?
If you get yourself some gasless stainless flux core wire.
And when you find it you want to know …
Can you flux core weld stainless steel when you have a home MIG welder?
Yes perhaps. Let me explain.
The Usual Stainless Steel Welding Advice
Most advice and books you read will tell you that if you want to weld stainless steel you have to MIG or TIG weld it.
And they say you’re going to need some solid stainless steel wire and shielding gas. You’ll find Tri Mix gas recommended (90% Helium, 7.5% Argon, 2.5% Carbon Dioxide). That’s the usual advice for MIG welding stainless steel.
And for the most part that’s true,
But, there’s another option: Stainless steel flux core welding wire.
Available Stainless Steel Welding Wire That’s Flux Core
You’ll find stainless steel welding wire on Ebay.
Welding wire that claims to be gasless stainless steel flux core wire. But you’ll struggle to find feed back on it.
And what feedback is there is isn’t great.
Some users complain that when the wire arrived it was stainless steel wire all right but not flux cored.
So the wire may not be what you think it is or as advertised.
And after extensive search on and off Amazon and Ebay.
I can tell you that you’ll find that Blue Demon is the main option for gasless flux cored stainless steel welding wire.
Blue Demon sells gasless stainless steel flux cored wire. You’ll find it readily available on Amazon and Ebay.
And user feed back is positive.
Want a walk through your options?
*Disclosure: This document contains affiliate links. And at no extra cost to you this site earns a commissions through these links should you decide to buy.
And later on in this article you’ll get the inside track on welding stainless steel with flux core welding wire.
Blue Demon Stainless Steel Welding Wire Flux Core Wire Choices
1. Blue Demon 308LFC Gasless Stainless Steel Flux Cored
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Reasons to Buy:
You’ll find it’s good stainless steel wire with solid user feed back.
You can use it to weld or repair without a separate tank of compressed gas all 300 series stainless steel up to 308.
And you can also weld those 430 stainless steel parts.
Reasons Not to Buy:
The 308LFC welding wire isn’t an all positions wire.
It’s rated F and H – for flat and horizontal welding positions.
When you’re welding up an stainless steel exhaust overhead this wire isn’t for you. You’ll get a poor weld and yourself covered in spatter.
Other Need to Knows:
When you compare it to a similar roll of non flux core stainless steel welding wire.
The 308LFC Blue Demon 1 lb. spool comes in around ten dollars more expensive. Which isn’t bad considering you won’t need the cost of a tank of gas to weld with it.
It’s available in 0.035 inch diameter size which many home 120 volt welders use. It’s also in 0.045 inch diameter size.
You’ll need at least 130 Amp to 150 Amp welding output from your welder to weld well with this filler wire.
2. Blue Demon 309LFC Flux Cored Stainless Steel Welding Wire Gasless
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Reasons to Buy:
You’ll find there’s good user feedback on this wire too.
The Blue Demon 309L Flux Core wire will weld without a cylinder of gas, 300 series stainless steels up to series 309.
You can also weld 309 stainless steel to 309 stainless steel with this wire.
It’s a really useful filler wire to have. Because it’ll weld 300 series stainless steels up to 309 to other mild steels. So when you’re looking to join stainless steel to mild steel this is the wire to use.
Reasons Not to Buy:
The 309LFC flux cored stainless steel welding wire isn’t an all positions wire.
It’s rated for F and H – flat and horizontal welding positions.
You’ll need to get that repair part out from where it is so that you can weld on the flat.
Other Need to Knows:
You’ll find it comes in 0.035 inch and 0.045 inch diameter sizes.
You’ll need at least 130 Amp to 150 Amp welding output from your welder. When you’re welding with this stainless steel flux cored wire.
3. Blue Demon 316FC-O Flux Core Stainless Steel Welding Wire, Gasless
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Reasons to Buy:
Another wire with great feedback.
You use this Blue Demon 316FC-O to gasless weld 316 stainless steel. Which is food grade stainless steel.
Reasons Not to Buy:
The 316FC-O welding wire isn’t an all position wire.
It’s rated for F and H – Flat and Horizontal welding positions.
Other Need to Knows:
Available in 0.035 inch and 0.045 inch diameter size.
Again you’ll need a minimum of 130 and to 150 Amp welding output from your welder. For you to weld this wire well.
Along with your Blue Demon 308L, or 309L and 316L. Consider getting yourself a tub of Hobart Anti Spatter Nozzle Gel (*Paid Link).
To keep your welding nozzle clean, just in case you get some BB’s.
Or some Anti Spatter spray for around the joint to help you with any spatter clean up.
If you’re not sure what nozzle gel is. Or what anti spatter spray is. And want to know more – you should check out this article on the site.
Reasons To Buy Gasless Flux Core Stainless Steel Wire
You’ll find there are some great reasons for using gasless flux core stainless steel welding wire. They are;
1. When you need to weld stainless steel outside.
Outdoors the wind can blow away your shielding gas.
You know that Tri Mix gas you spent a fortune on?
The wind can blow your gas away leaving you with a bad weld.
MIG welding where you use solid wire and shielding gas. Is typically an inside welding process for just this reason.
Or you’ll need a wind shield setup of some description to MIG weld out in the open.
2. There’s the cost of a gas set up.
That means, your gas hose. The gas cylinder itself. And a suitable regulator for your Tri Mix gas.
And of course a MIG welder that’s capable of providing the welding output needed.
3. What if you’re only welding stainless steel occasionally. Or on a single small project. Do you really want to go to the extra costs of solid MIG wire and gas?
4. Sourcing Tri Mix in small cylinder sizes is tricky.
Can you get small cylinder sizes of Tri Mix gas in your area?
5. Do you have the space to store a Tri Mix cylinder? And do you have the means to transport it?
Most people don’t realize that flux core welding stainless steel without gas is even a thing.
Is Stainless Steel Flux Core Wire Expensive?
You may think buying Blue Demon stainless steel gasless flux core wire expensive. When you compare it to the cost of solid stainless steel filler wire.
But stainless steel solid wire needs shielding gas to weld it with. And Tri Mix is often the shielding gas of choice.
And when you factor in the cost of a tank of Tri Mix gas. On top of your solid stainless steel MIG wire. The cost of self shielded gasless wire doesn’t seem so bad.
Tri Mix gas is expensive. Can you justify the cost for your project?
Plus you might not be able to source the gas in your area.
Or maybe you can’t store or transport home a large cylinder.
Note you buy the Tri Mix tank pre mixed. Don’t try and mix the gasses yourself.
Is The Blue Demon Gasless Stainless Steel For Home Shop Use?
0.035 inch diameter. Or if you can find it 0.030 inch is the wire size to use for a home welder running on 120 volts.
You’ll find the Blue Demon gasless stainless steel in 1 lb. and 2 lb. spools. Perfect for your home garage use.
Though your practice sessions. And finding the right settings on your welder may quickly run you through a 1 lb. spool before you’ve got to the actual job in hand.
There are other types of stainless steel flux core wire. Ones that do need shielding gas. This is called double shielding and you’ll find some info on those later in this article.
Difference Between Stainless Steel Solid Wire And Welding Stainless Steel Flux Core
It’s worth taking a few seconds to understand Stainless steel solid MIG wire. And Stainless steel flux core wire are not the same.
Solid stainless steel welding wire is, well, solid.
Sounds obvious I know. But it’s an important point. There’s just pure stainless steel in it. Plus some stuff to make it easy to weld with.
And to weld with stainless steel MIG wire you’ll need to use shielding gas. That gas is typically Tri Mix. You’ll use it protect your weld from contamination from the surrounding air.
Contamination that would lead to a poor weld and that’s why you need it.
But what if you don’t want to use gas?
Two Types Of Stainless Steel Flux Core Wire
The other type of flux core wire for stainless steel is self shielded stainless steel flux core. Also referred to as gasless stainless steel flux cord wire.
It’s what this article is all about.
You need no separate tank of shielding gas. So it’s very convenient for occasional use. Or you as a hobbyist welder to use.
Flux core stainless steel welding wire has stainless steel around the outside.
And special chemicals called flux through the middle. This flux melts as you weld forming a gas to shield your weld.
MIG Welding Stainless Steel With Flux Core Wire
You’ll find there is another type of stainless steel flux core wire. It’s called gas shielded flux core wire (FCAW-G). You’ll also hear it called double shielded and sometimes dual shielded.
Because it has two shields. The flux inside and you use a cylinder of shielding gas.
And you can use other shielding gasses with this wire. Like Carbon Dioxide and high Argon Oxygen gas mixes.
Of course you’ll need a true MIG set up to use double shielded wires.
And that means a MIG welder that feeds separate shielding gas. Plus you’ll need a gas tank and regulator.
The gas shielded stainless steel flux core wires produce great welds.
This section is just a brief overview of flux core wire. If your curiosity is tweaked, you’ll find a document here all about flux core wire.
What Kind Of Stainless Steel Do You Have?
The first step in deciding what you use to weld your piece with is to work out what kind of stainless steel you have. The steel you’re welding is called the base metal.
300 series stainless steel is the most widely manufactured and used.
For example, there’s type 304 also known as 18/8. There’s type 308, and 309.
Type 316 is generally used in the Food and Drink industry, as these steels don’t taint the taste of the food. And 315 stainless steel is easily cleaned and sterilized for holding food and drink.
If your stainless steel is magnetic then it may be type 409, which is typically seen in car exhausts.
Type 430 is used in washing machine interiors, refrigerators, dishwashers. etc. These forms of thinner steels (e.g. type 430) are more difficult to weld as welding can crack their structure.
This change in structure can result in something called weld decay. Weld decay causes the weld to rust and fail over time. The last thing you want with stainless steel.
And even though your steel may not look like it needs a clean before you weld. It’s a good idea to check for and clean off any oil or grease. And prepare the surface with a grinder using a stainless steel compatible disc.
Choosing Your Flux Core Welding Stainless Steel Wire
You should know what kind of steel you are dealing with. Because then you can find the right welding wire to use as filler material.
Match type 308L with type 308 base metal.
The L after the stainless steel flux core type number stands for low carbon. Low carbon stainless steel flux core filler metal helps stop weld decay. So look for the L on your stainless flux core welding wire.
Type 308 wire will also weld most 300 series stainless steel up to type 308.
Type 309 flux core welding wire for stainless steel. Will weld 300 series stainless steels up to and including type 309. It’s also great for welding type 300 series stainless steels to mild steel.
Type 316L stainless steel will weld 316 stainless steel. Type 316 stainless steel is a special steel.
It’s classed as food grade and is used in the food and drink industry. It takes skill to weld type 316 well and welding these types of steels is usually done by a professional.
Because a weld that leaves tiny gaps. Or dips or holes where microbes can live and multiply.
Is disastrous in a container storing food or on a surface where you prepare food. Type 316 stainless steel needs care when you weld.
Do check the welding parameters chart of your stainless steel flux core welding wire. To check the stainless steels the manufacturer says their welding wire will weld.
Important Things For You To Think Of When Buying Flux Core Wire For Stainless Steel
One thing to pay attention to is the size of wire diameter you buy. No point buying 0.045 inch diameter wire when your flux core welder will only feed 0.035 inch or smaller.
It’s also true that there’s no point buying a 25 pound spool because that’s the minimum spool size the wire comes in, when your welder can only take a maximum of a 10 pound spool.
Because you can’t feed it and you need to ensure you store it well.
And don’t even try to transfer to a smaller spool because these spools are precision wound and you’ll end up with a rats nest of wire.
Stainless flux core welding wire is more delicate than stainless steel solid wire. It doesn’t need a spool gun to feed it but rough handling will break the wire.
You need your home flux core welder to be capable of generating enough heat output. And that means a true 90 Amp plus, preferably 130 Amp or more.
You’ll also need your flux core or MIG welder sent to DCEP polarity. More on that later.
Setting The Correct Polarity Is An Important Thing
If your welder is a cheaper flux core only welder, the question you may be asking is: Can I weld stainless steel with a gasless MIG welder?
Some of the cheapest gasless welders have MIG in their title but they don’t feed shielding gas. They often also claim to weld stainless steel but it’s unlikely.
First check that your machine can reverse its polarity.
As many cheaper low amp flux core welders will weld with mild steel flux core welding wire. That wire runs on DCEN polarity – Direct Current MIG Gun Negative.
Stainless steel flux core welding wire Must Be run with DCEP polarity – Direct Current MIG gun Positive.
Trying to weld flux core wire stainless steel on a DCEN only machine will simply not work.
I think some of the negative feed back on welding stainless with flux core wire reflects the folks who have tried to do this.
Have You A Home Welder That’s Up To The Job?
Assuming you’ve your flux core or MIG welder at home plugged into an exclusive 20 Amp or 30 Amp circuit (have nothing else plugged into the circuit when you’ve your welder running so that you get the maximum Amps available)
You need a welder that can produce a true 90 Amps. Preferably the 130 Amp minimum most stainless steel flux core welding wire specifications asks for.
Your machine needs to produce enough amperage to melt the wire and the stainless steel base metal. Welding stainless steel with flux core wire needs a decent amount of heat output from the welder to weld well.
YouTube Video Showing Blue Demon Flux Core Stainless Steel Wire
Here’s an excellent YouTube video on welding stainless with flux core that you should enjoy. If you’ve not welded stainless steel flux core before it’ll set you up nicely.
In the below nine and a half minute video Bob Moffat, welding instructor observed while welding stainless steel with flux core wire;
He saw a ball or bubble effect on the end of the flux core stainless steel wire, which is different to welding with mild steel flux core wire.
This bubble effect is due to the different electrical characteristics stainless steel flux core wire has as opposed to mild steel flux core wire.
The weld sounded strange not the usual sizzle sound you would expect to hear welding mild steel. But that’s to be expected. Welding stainless steel flux core sounds different.
He welded 10 gauge stainless steel in a fillet weld
1/4 inch stainless steel bent to allow a view of how the wire does on a corner fillet weld, inside and out.
He ran the wire hot and went a bit faster.
Your welder has to be capable of DCEP reverse polarity.
You need 3/4 to 1 inch stick out – as recommended by the wire welding parameter chart.
He tried pushing into the corner and then pulling into the corner to see if the different welding methods generated more spatter or affected the weld produced.
He saw no excessive spatter.
I think you’ll agree the welds look impressive.
The advantages: The flux core wire stainless steel welded well. No need to use separate shielding gas so would be great for occasional use when you’ve a small job to do and of course for an out door weld.
Have a look at the video here.
Stainless Steel FCAW without Gas
Video Credit : Weld.com
Other Makes Of Stainless Steel Welding Wire Flux Core
Here’s another brand of flux core welding wire for stainless steel for you.
ESAB sells Core-Bright in types 308L, 309L and 316L flux core stainless wire.
It’s self shielded. Though you’ll need a beefy welder to weld with it. Its smallest diameter size is 3/32.
And you’ll need a welder able to produce 350 Amp plus to weld.
And there you have it, the best search into stainless steel welding wire flux core.
Benefit from the research and save yourself time searching around.
And get yourself going on that stainless steel repair.