Stainless pulse with Argon?

[Hood]

Have done a deal on a pulse welder and yesterday I was given 3 rolls of stainless wire for free. I only ever use my Mig for heavier Alu as I prefer tig or stick for other materials/thickness's but seeing as I have the wire and soon to be a pulse Mig then I might as well try it out.

I know you are meant to use Argon with 2.5% C02 for stainless with short circuit transfer but wondering if spray transfer would do an OK'ish job with pure Argon?

Was going to get a bottle of gas for the stainless but the local place for rent free only does 5% CO2 which would not be very good. Could go and get a bottle from the BOC or Air Products I suppose but ......

 

[WorkshopChris]

We used to use Stainshield Universal or one of the variations on stainless mig, this has added helium to help reduce splatter.
But we were not paying the bill!!! However might be worth getting a price from BOC or air products used to have a similar mix.

 

[Hood]

We used to use Stainshield Universal or one of the variations on stainless mig, this has added helium to help reduce splatter.
But we were not paying the bill!!! However might be worth getting a price from BOC or air products used to have a similar mix.

Hopefully spatter should not be too much of an issue with pulse Mig.
Might end up just getting a smallish bottle of suitable gas but it is not so much the cost of the gas it is the rental that irks me, especially when I will likely not use it much.

 

[backpurge]

You either need Argon with 2.5% CO2 or one of the Stainshield flavours, the programmes in a pulsed MIG are not written around pure argon, if you want to weld stainless effectively you need a small active component in the gas to stabilise the arc and give you good fusion, using pure argon will stick the job together but that's about all.

You will now get loads of folk coming on saying they successfully use anything from pure Argon to Argoshield heavy, but as I've said, that is the difference between welding it correctly and gobbling it together

 

[Richard.]

Have done a deal on a pulse welder and yesterday I was given 3 rolls of stainless wire for free. I only ever use my Mig for heavier Alu as I prefer tig or stick for other materials/thickness's but seeing as I have the wire and soon to be a pulse Mig then I might as well try it out.

I know you are meant to use Argon with 2.5% C02 for stainless with short circuit transfer but wondering if spray transfer would do an OK'ish job with pure Argon?

Was going to get a bottle of gas for the stainless but the local place for rent free only does 5% CO2 which would not be very good. Could go and get a bottle from the BOC or Air Products I suppose but ......

Yes and no.
Yes you can run stainless wire in spray transfer I've never been told it's a dip transfer wire only.
No you can't run it in pure Argon. It doesn't work, you need a small % of active gas. As you say proper. Stainless shields are 2.5% active.

 

[Hood]

You either need Argon with 2.5% CO2 or one of the Stainshield flavours, the programmes in a pulsed MIG are not written around pure argon, if you want to weld stainless effectively you need a small active component in the gas to stabilise the arc and give you good fusion, using pure argon will stick the job together but that's about all.

Ok, thanks, looks like I will have to go for some then

You will now get loads of folk coming on saying they successfully use anything from pure Argon to Argoshield heavy, but as I've said, that is the difference between welding it correctly and gobbling it together

Oh I know all about that, as said don't do anything other than Alu with the mig but was needing to do a bit of steel tray for my plasma table and it was a PITA with the tig so I did it with the mig. It looked crap but held it together but to be honest it was a wonder it did, I only had 0.6mm wire, smallest tip I had was 1mm and the only gas I had was Argon

 

[Hood]

Yes and no.
Yes you can run stainless wire in spray transfer I've never been told it's a dip transfer wire only.
No you can't run it in pure Argon. It doesn't work, you need a small % of active gas. As you say proper. Stainless shields are 2.5% active.

Presume that when using Pulse it would be considered spray?

Looks like I will have to get some gas then, quite fancy trying the stainless with the pulse.

 

[norlander]

What is the characteristic of the MIG process that requires the % of active gas, ie, pure argon is ok for TIG, but active gas addition is needed for MIG

small active component in the gas to stabilise the arc and give you good fusion,

is it because with TIG there is a constant stable arc??
Numpty question I spose but interested numpty here.

 

[Hitch]

We use Inomaxx (AP) for stainless Mig in the workshop, but for the limited amount we do on site, we have a Hobbyweld cylinder if 98/2. Might be worth looking into for minimal usage.

 

[Richard.]

It's far from a numpty question it's a brilliant question and I'll do my best to answer it.
With Tig your electrode is not consumable in the respect it's not the filler. Any oxides from any amount of active gas will attack the electrode and cause an effect on how the arc is delivered. This is the reason a completely inert shield is essential. Your creating a pool purely on current and while different gases (helium for example offer better or hotter use of that current your still not going to introduce filler into the pool until it's fully developed so you will always have sufficient pen and fusion with argon alone.
With mig the wire is the consumable and it doesn't need to be protected against active gases like your tungsten does because your burning it. But your also not in a position to fully control when that wire is going into that pool it's fed consistently. So you need the active gas to ensure good pen,fusion and material wetting are going to happen which is something you don't need to worry about with Tig as you can achieve all that with current and technique alone.
I know what I'm trying to say but that's such a good question I'm struggling to get the right words for it. Backpurge is better at this stuff.

 

[norlander]

Ta, I think I got my head round that

 

[backpurge]

What is the characteristic of the MIG process that requires the % of active gas, ie, pure argon is ok for TIG, but active gas addition is needed for MIG



is it because with TIG there is a constant stable arc??
Numpty question I spose but interested numpty here.

As Richard says, it's a great question and he's just about hit it on the head

 

[norlander]

One last question,

the programmes in a pulsed MIG

re programmes etc; is that a "synergic" inverter MIG, I was offered a GYS Pearl but thought it was over the top for my use to be honest.

 

[backpurge]

Yep, synergic. Makes setting the right parameters so easy, if it also runs in pulsed it is well worth investing in if you have the work for it

 

[Mr shiney]

I just use Argoshield lite with stainless and it gives a lovely finish.

 

[Hood]

Does it not corrode at the weld?

 

[Brad93]

What machine did you end up getting Hood?

 

[Hood]

What machine did you end up getting Hood?

 

[Brad93]

You'll have to ask Matt what gas this was but this is synergic twinpulse on a S3. 6mm stainless plate, not sure what the wire was, 1.0mm I think.

 

[Brad93]

View attachment 105022

Niiceee!