Questions about welding stainless

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Re: Questions about welding stainless

Postby bluc » Mon May 31, 2021 8:08 pm

Thanks :handgestures-thumbupleft:
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Re: Questions about welding stainless

Postby iOnaBender » Mon May 31, 2021 8:13 pm

Hi bluc,

I'm not a boiler maker but learned the TIG craft on many a nightshift when working for Kraft foods, as a result all my camping and camp oven gear is all stainless steel. Minimise space with water or a purging dam (hard on a boiler compared with tri clover fittings and SS pipe). The gun fitters/boilies used masking tape with 6-12 holes made from TIG filler wire. They used a second flow meter on a Y piece with around 7-8 L/pm (I think it was). Once setting up and starting purge gas flow it was time for a coffee before attempting the weld. When you first strike an arc, hang around to get heat and importantly full penetration to make your purge weld successful. Also when you have completed the full lap, don't just pull your torch away, roll your wrist to draw an increasing arc until extinguished (this eliminates pin holes). The larger the pipe diameter the easier it is from my experience, 20mm tube/pipe was a bitch to start and finish! For me personally the most important is to take your time, MIG & ARC are very fast in comparison to a quality TIG weld

Hope this helps or clarifies a few points for you?
Last edited by iOnaBender on Mon May 31, 2021 8:14 pm, edited 1 time in total.
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Re: Questions about welding stainless

Postby LikkerSheWillLoveIt » Tue Jun 01, 2021 7:00 am

iOnaBender wrote:Hi bluc,

I'm not a boiler maker but learned the TIG craft on many a nightshift when working for Kraft foods, as a result all my camping and camp oven gear is all stainless steel. Minimise space with water or a purging dam (hard on a boiler compared with tri clover fittings and SS pipe). The gun fitters/boilies used masking tape with 6-12 holes made from TIG filler wire. They used a second flow meter on a Y piece with around 7-8 L/pm (I think it was). Once setting up and starting purge gas flow it was time for a coffee before attempting the weld. When you first strike an arc, hang around to get heat and importantly full penetration to make your purge weld successful. Also when you have completed the full lap, don't just pull your torch away, roll your wrist to draw an increasing arc until extinguished (this eliminates pin holes). The larger the pipe diameter the easier it is from my experience, 20mm tube/pipe was a bitch to start and finish! For me personally the most important is to take your time, MIG & ARC are very fast in comparison to a quality TIG weld

Hope this helps or clarifies a few points for you?



I’d say closer to 11L/M, the argon helps with penetration, that being said, if you are running gas deflectors on the cup, you can back it off to probably 9L/M. If you are really good with your eyeballs, you will see a slight, kind of “Northern Lights” definitely of green and blue tinge, surrounding the arc, you will also notice 2 sometimes 3 tiny bubbles in the weld puddle, you can get them to spin around the electrode, I’ve only managed to get that once (then I started looking at that and not the weld) but my mate who spent 10 years purge welding for milk factories, the prick can do it everytime!! They are both signs of argon mixing, the argon temp coming off the torch side is much hotter than that on the inside of the purge, that’s when you know your purge is successful.

The big argument about MIG and ARC being faster than TIG, I disagree, TIG is fast if you know what you are doing. The clean up of MIG and ARC spatter and weld, takes ages. However, MIG and ARC do have there places. I hate MIG welding. Give me a TIG and I’ll crank the amps up, lay wire out on the job and be just as quick with a TIG with none of the clean up.

Just my opinion.
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Re: Questions about welding stainless

Postby bluc » Tue Jun 01, 2021 7:47 am

Thanks. Yea pumped to get into it. :handgestures-thumbupleft:
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Re: Questions about welding stainless

Postby B-Man » Thu Jun 03, 2021 10:16 pm

Anyone offer some tips on my welds.
Didn't do many practice welds. Was happy enough with what I produced. Not perfect by any means. Just didn't want to use up all my gas practising and not be much better.
I did back purge but rather poorly and was probably to no benefit.

20201230_143748.jpg


20201230_134816.jpg


Screenshot_20210603-214438_Photos.jpg




I didn't get full penetration but if I ran any hotter I would blow holes.
Any tips on how to get that nice filler material build up. Mines very flat.
And hard to explain but I've watched a heap of videos and seen one bloke do some spot/tack welds where it was like a quick pulse and it tacked it and then the just done that 20 times and it fused everything up. Filled a hole using it too. can't find it again though. Any ideas what that's called or how to do it?
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Re: Questions about welding stainless

Postby scythe » Fri Jun 04, 2021 7:13 am

I'm only a machinist and not a boily...
But,
Slow down your movement to increase penetration.
Feed more filler rod to fill it more (strange but true).

You can absolutely just tack things and get it to seal, just takes longer.

Photo of your back purge is a bit blurry so can't see if it's actually sugared, but you will be able to feel it for sure.
Drag a tissue over it, if the tissue does not get torn to shreds by the weld surface it's all good.
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Re: Questions about welding stainless

Postby LikkerSheWillLoveIt » Fri Jun 04, 2021 7:32 am

If you can, take a photo of the control settings on your machine, I may be able to help with setup. I’m thinking your amps are too high.

Are you using 2% Thoriated Tungsten (Red Tip)?

Now for technique,
#1 GET COMFORTABLE! Let’s face it, you are trying to melt stainless in a very specific spot with a tiny electrode sharpened to a needle point. Use a piece of anything you’ve got lying around to give yourself a hand rest that still lets you move your hand around the job. Start each weld in an uncomfortable position first, ending in a more comfortable position. Sounds stupid, but it works. It’s really hard to get really good hand stability if you aren’t comfortable, resulting in your hand shaking and the weld pool moving all over the place, worse still dipping your tungsten.

#2 GET COMFORTABLE!

#3 DONT RUSH! Like everything in this hobby. Shit takes time. Yes high amps means you can weld faster, if you have the skill to weld faster. If you can’t get full penetration and a nice clean weld with lower amps and moving slowly, how are you going to go when you are trying to speed it up???

Sorry if that comes across arrogant, I’m trying to channel my first Leading Hand!

When I first started, the scrap bin got put in front of my bench and I stood there for 45 hours a week for about 3 1/2 weeks until the Production Manager said I could start welding RHS brackets, and that was with about 25 different people giving me hints and tips.

By the looks of your welds you aren’t getting your tungsten close enough to the weld pool, the closer you are, the more concentrated the heat is, therefore the more penetration you get without over heating the surrounding material. Yes some people (and the textbook) say your weld should be 3 times the width of the material thickness you are welding, bullshit! Maybe for structural steel or high pressure pipe, but not in all instances. I weld a heap of 3mm and I can tell you now I have NEVER had a weld 10mm wide on stainless!

Practice, practice, practice! Which is easy to say if you aren’t paying for argon! BUT! You can get the “feel” for it, with the welder turned off. Watch the YouTube videos, watch how they move, now try it with the welder off and no helmet on so you can see your hands and know what they are doing. Hand Eye coordination is one thing, but then trying it blind with helmet and TIG torch, that’s a whole new thing!

Look at your torch angle. If you are doing a fillet weld, as you have, hold the torch at 45 degrees to the right angle of the 2 materials, now point your torch the way you want to weld at around 10-15 degrees and hold your wire 90 degrees to the torch. I’ll go into the shed later and take some photos for you.

Filling holes is hard, it helps if you can clamp a piece of aluminium or brass behind, stainless doesn’t stick to it and it acts as a heat diffuser.

If I was welding a 4” ferrule onto a keg like you have done, I’d be tacking every 20mm before welding, and doing those tacks as you would tighten wheel nuts, don’t just go around in one direction, make it random and let it cool.

It’s hard to teach someone to TIG weld when you are sitting beside them.

Don’t ever stop now, you will have a light switch moment.

The weld in your second photo looks nice and even which is good.
Last edited by LikkerSheWillLoveIt on Fri Jun 04, 2021 7:38 am, edited 1 time in total.
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Re: Questions about welding stainless

Postby bluc » Fri Jun 04, 2021 2:11 pm

Been reading about pickling paste and some mixed info on weather or not its available to home hobbyists in Qld. Is there a type a home user can buy?
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Re: Questions about welding stainless

Postby scythe » Fri Jun 04, 2021 4:15 pm

Yeah you can buy it easy enough.
But make sure you get the PPE first and watch where you ate dumping the rinse water, it now contains heavy metals that need proper disposal.

Look into the rabbit hole that is passivation with citric acid.
It won't eat heat scale but it will make it stainless again.
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Re: Questions about welding stainless

Postby bluc » Fri Jun 04, 2021 4:21 pm

Grind then passivate?
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Re: Questions about welding stainless

Postby LikkerSheWillLoveIt » Fri Jun 04, 2021 5:18 pm

Be careful with that pickling paste. It’s Hydrofluoric and Nitric acid. I had the misfortune of getting it in my eye, yes I had eye protection on, but it still got there. 8 hours at hospital getting it flushed. Hurt like hell.
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Re: Questions about welding stainless

Postby B-Man » Fri Jun 04, 2021 5:40 pm

scythe wrote:I'm only a machinist and not a boily...
But,
Slow down your movement to increase penetration.
Feed more filler rod to fill it more (strange but true).

You can absolutely just tack things and get it to seal, just takes longer.

Photo of your back purge is a bit blurry so can't see if it's actually sugared, but you will be able to feel it for sure.
Drag a tissue over it, if the tissue does not get torn to shreds by the weld surface it's all good.


I just wanted to know what setup was used for the tacks. It was a half second burst and done, it had fused the metal together.

The photo was to show lack of penetration. The 2 bits in that photo were tacks. Anything that did have full penetration or I blew a hole in and had to fill did sugar.
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Re: Questions about welding stainless

Postby B-Man » Fri Jun 04, 2021 5:59 pm

LikkerSheWillLoveIt wrote:If you can, take a photo of the control settings on your machine, I may be able to help with setup. I’m thinking your amps are too high.

Are you using 2% Thoriated Tungsten (Red Tip)?

Now for technique,
#1 GET COMFORTABLE! Let’s face it, you are trying to melt stainless in a very specific spot with a tiny electrode sharpened to a needle point. Use a piece of anything you’ve got lying around to give yourself a hand rest that still lets you move your hand around the job. Start each weld in an uncomfortable position first, ending in a more comfortable position. Sounds stupid, but it works. It’s really hard to get really good hand stability if you aren’t comfortable, resulting in your hand shaking and the weld pool moving all over the place, worse still dipping your tungsten.

#2 GET COMFORTABLE!

#3 DONT RUSH! Like everything in this hobby. Shit takes time. Yes high amps means you can weld faster, if you have the skill to weld faster. If you can’t get full penetration and a nice clean weld with lower amps and moving slowly, how are you going to go when you are trying to speed it up???

Sorry if that comes across arrogant, I’m trying to channel my first Leading Hand!

When I first started, the scrap bin got put in front of my bench and I stood there for 45 hours a week for about 3 1/2 weeks until the Production Manager said I could start welding RHS brackets, and that was with about 25 different people giving me hints and tips.

By the looks of your welds you aren’t getting your tungsten close enough to the weld pool, the closer you are, the more concentrated the heat is, therefore the more penetration you get without over heating the surrounding material. Yes some people (and the textbook) say your weld should be 3 times the width of the material thickness you are welding, bullshit! Maybe for structural steel or high pressure pipe, but not in all instances. I weld a heap of 3mm and I can tell you now I have NEVER had a weld 10mm wide on stainless!

Practice, practice, practice! Which is easy to say if you aren’t paying for argon! BUT! You can get the “feel” for it, with the welder turned off. Watch the YouTube videos, watch how they move, now try it with the welder off and no helmet on so you can see your hands and know what they are doing. Hand Eye coordination is one thing, but then trying it blind with helmet and TIG torch, that’s a whole new thing!

Look at your torch angle. If you are doing a fillet weld, as you have, hold the torch at 45 degrees to the right angle of the 2 materials, now point your torch the way you want to weld at around 10-15 degrees and hold your wire 90 degrees to the torch. I’ll go into the shed later and take some photos for you.

Filling holes is hard, it helps if you can clamp a piece of aluminium or brass behind, stainless doesn’t stick to it and it acts as a heat diffuser.

If I was welding a 4” ferrule onto a keg like you have done, I’d be tacking every 20mm before welding, and doing those tacks as you would tighten wheel nuts, don’t just go around in one direction, make it random and let it cool.

It’s hard to teach someone to TIG weld when you are sitting beside them.

Don’t ever stop now, you will have a light switch moment.

The weld in your second photo looks nice and even which is good.


It's a unimig razor 200a ac/dc
1.6mm 2% Thoriated Tungsten (Red Tip)
1.6mm 308L filler rod
I ran somewhere between 40 and 80 amps(non pulse) just depending on my speed, gap, how hot it was etc.
Have just started trying out the pulse setting.

Was running at 45° with about 30° tilt and filler rod at 90° to torch. Well I start like that. Sometimes I wasn't ending like that.
I get comfortable have a table at the right height and and sitting on an old office chair. Normally rest my hand/arm on the item or edge of the table

It's okay I don't take offence. I'm learning and willing to take it all in.

Great I probably am a little bit far away with the torch. After the odd tungsten dip I do naturally move it away.

My practice is my projects. I'm not looking for them to be perfect. As long as they work and welds are getting better I'm happy.

Im pretty happy with what I have done considering the time I have spent. Its always good to get some advice to try on the next weld. Especially if someone experienced can look at the weld and point out what you have done wrong.
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Re: Questions about welding stainless

Postby LikkerSheWillLoveIt » Fri Jun 04, 2021 7:44 pm

Excuse me if I’m repeating myself. I’ve got the same machine analogue, and the 320amp digital at work . I run a nice big cup #10 at least, it lets you have a fair amount of tungsten stick out, so you can get into corners. If you haven’t already, get onto the clear Pyrex cup, Unimig have them now and are available from Tradetools, they have gas diffusers in the cup which slows the gas flow so you get more of a lingering cloud rather than a jet. You can see through the cup, and I love welding with them, no good for aluminium, they destroy themselves in AC current.

40-80 amps is way too hot. I weld tube to ferrules and but welds in pipe at around 32amps, but I generally fuse them with no wire. Ferrules to keg in a fillet weld maximum I would go would be 45-48 amps. 3mm stainless I’ll be hitting 80ish. Play with your arc force, if you turn it right down you will get a wide arc, crank it up and it will narrow down and push more heat through to help with penetration.

I’ll happily lay my cup on the work piece, that gives good stability, also helps with weaving. I know it’s hard when you are using your own gas, but pre and post flow gas, really help with maintaining your tungsten, makes starting each weld really nice.

I don’t and won’t use pulse, just a personal thing. It can be a good tool for learning timing with dipping wire and when to move. I like to move, hold, dip wire in, hold, move, hold, dip wire in, hold, repeat. I never weld with the torch continuously moving. I find once I move, hold, the weld pool opens up, dip the wire and hold to let it fill and flatten out, this gives you the penetration. It’s just my technique, I started doing it on aluminium and it worked well so now it’s what I do.

I love welding, in case you didn’t notice. I’ve built some really cool stuff!
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Re: Questions about welding stainless

Postby B-Man » Fri Jun 04, 2021 8:02 pm

I was looking for the pyrex cups but they didn't make them for the t2 torch. I had heard they do now.
Will have to grab a couple. I'm still using the std #7 cup

will try those settings and your move hold method next time I do something and see how I go. That sounds better in my head as I felt I was melting too fast and having to rush the run sometimes but still didn't get the penetration. Have also heard that back purging helps with penetration too. So once I set that up properly I think I'll be on a winner. Cheers. Now need to start making a second boiler to test it all on
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Re: Questions about welding stainless

Postby bluc » Fri Jun 04, 2021 8:09 pm

I found this pickling paste and it claims you dont need a poison license wich I assume is for the nitric/hydrofluric version
https://www.hampdon.com.au/Able-Inox-St ... Paste-500g
Anyone have experience with it?
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Re: Questions about welding stainless

Postby bluc » Fri Jun 04, 2021 8:11 pm

Been looking at those pyrex cups and I reakon is the way i will head. :handgestures-thumbupleft:
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Re: Questions about welding stainless

Postby LikkerSheWillLoveIt » Sat Jun 05, 2021 8:23 am

bluc wrote:I found this pickling paste and it claims you dont need a poison license wich I assume is for the nitric/hydrofluric version
https://www.hampdon.com.au/Able-Inox-St ... Paste-500g
Anyone have experience with it?



Sorry mate. Never used it. I can swing by my welding supplier on Monday and have a chat with the guys there.
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Re: Questions about welding stainless

Postby bluc » Sat Jun 05, 2021 9:16 am

:handgestures-thumbupleft:
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Re: Questions about welding stainless

Postby clintonb » Sat Jun 05, 2021 5:33 pm

bluc wrote:I found this pickling paste and it claims you dont need a poison license wich I assume is for the nitric/hydrofluric version
https://www.hampdon.com.au/Able-Inox-St ... Paste-500g
Anyone have experience with it?

I have used it on my 118l keg boiler when I tiged the drain into mine. It was not as harsh as I remember other pickling pastes but did the job. Many years ago when I first started working, one of my jobs was to pickle paste hundreds of ss welds. I didn't know if was so dangerous and didn't wear glasses or any other PPE except a pair of overalls. Every now and then I knew I had spilt as I could feel a burning sensation, I would just rinse my skin with water and keep working. At the end of the week my overalls would have acid stains all of them. Also if you are going to do a bit of DIY tig work go easy as those boilers aren't thick ss. Good luck :handgestures-thumbupleft:
Last edited by clintonb on Sat Jun 05, 2021 5:35 pm, edited 2 times in total.
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