Newbie now with TIG.

[Hood]

Does 130amps not seem a lot for that thickness? I don't do much steel, mainly stainless and Alu but even Alu I wouldn't expect to be as high as that.
Today I was welding 12mm stainless to 2" Sch40 pipe and I was only at 130amps.

 

[dazza]

I think you're arc length is too long and you're possibly contaminating the tungsten resulting in the brownish soot.

Yep i made a right mess of most of it. I've marked my first run where everything was going well. Think i lost my temper in the end and kept going although i'd contaminated the tungsten.

Are you using a decent mask?

I have an esab warrior mask. I need to rig up some better lights as i cannot see anything until i start the arc and by then i've already messed it up.

 

[Richard.]

Does 130amps not seem a lot for that thickness? I don't do much steel, mainly stainless and Alu but even Alu I wouldn't expect to be as high as that.
Today I was welding 12mm stainless to 2" Sch40 pipe and I was only at 130amps.

You always weld to your thickest material.
In Dazs case that's 4mm.
120-130 amps is about spot on.

 

[Hood]

You always weld to your thickest material.
In Dazs case that's 4mm.
120-130 amps is about spot on.

Just seemed high to me but as said very rarely do steel. Stainless is more fluid than steel so will likely need less current, certainly does with stick welding anyway.

 

[dazza]

Is that tubing about 1.6mm wall?

If so I'm heading down the workshop to do some bits in a minute (yes I'm mad, -2 outside and unheated). I think I have some tune that size I could mock this joint up. You're tacks looks lovely so we know you've got enough heat there to start with

Its 1mm wall. Don't bother mocking anything up mate i just need more practice. Problem is i'm all over the place, aluminium one minute flat out like a lizard drinking, then on to some 0.5mm stainless. Then 1mm to 4mm with 1mm rod. Which was not too bad as i had to go quick.

Does 130amps not seem a lot for that thickness? I don't do much steel, mainly stainless and Alu but even Alu I wouldn't expect to be as high as that.
Today I was welding 12mm stainless to 2" Sch40 pipe and I was only at 130amps.

Yes it is too hot, Richard got this right the other day, I was at 110/120 amps but it was too cold due to using too much filler (i think) So i upped the amps to 130 but used a lot less filler so i think it got a bit warm.

 

[dazza]

I know this looks bad but i think the first run went down nice until i dipped the tungsten.

I've marked it below.

 

[Hood]

I'd probably be at more like 180 for that

Really, must be down to different techniques or something.
Don't have a decent pic of it but here is a blown up section of a pic I had. Not the neatest Fillet and lap

 

[Hood]

To be honest I would normally be using stick for that but was just wanting to play with the new watercooled torch

 

[Richard.]

Just seemed high to me but as said very rarely do steel. Stainless is more fluid than steel so will likely need less current, certainly does with stick welding anyway.

Rough rule of thumb to work out where in the dial you need to be around is
Stainless 25 amps per 1mm
Steel 30 amps per 1mm
Alu 40 amps per 1 mm.
Work to your thickest piece.

Edit*. Joint type , part size, actual design. Etc all play a big role in how accurate and inaccurate that rule of thumb can be. It gets you in the rough ball park for most stuff.

 

[Hood]

Rough rule of thumb to work out where in the dial you need to be around is
Stainless 25 amps per 1mm
Steel 30 amps per 1mm
Alu 40 amps per 1 mm.
Work to your thickest piece.

Edit*. Joint type , part size, actual design. Etc all play a big role in how accurate and inaccurate that rule of thumb can be. It gets you in the rough ball park for most stuff.

These are way higher than I would start, maybe my technique plays a part, maybe machine, who knows. I do remember when I got the TecArc 251 I had to lower the current compared to what I had on the previous welders (Paweld 200amp analogue and crap LTS fire starter one) but the new Parweld seems to be consistent with the TecArc.

 

[Richard.]

These are way higher than I would start, maybe my technique plays a part, maybe machine, who knows. I do remember when I got the TecArc 251 I had to lower the current compared to what I had on the previous welders (Paweld 200amp analogue and crap LTS fire starter one) but the new Parweld seems to be consistent with the TecArc.

Perhaps you travel slower than me. If that's the case at these current levels you will burn through thinner materials and likely undercut on thicker. Beware though welding too cold even if your fusing properly creates excessive heat input by going too slowly.

 

[Richard.]

And like I say it's a very rough indication. A fillet joint will need more and an outside corner a good chunk less. A big item will suck heat away much quicker and small item will not it will get hot quick and your current will need to be very different between the two case scenarios especially with Alu as it conducts so well.
Working close to plate edges and in the middle makes a huge difference to where you put your current as well. So there is a lot more to consider with current and that rule of thumb is a crude staring point but in reality can be way off.

 

[Hood]

Ok was wondering if I was just imagining that I would normally go about 130/140 as a start point for a fillet in 4mm Alu so when I got back to the workshop I gave it a go.
4mm Alu about 150 x 100 lower plate and 150 x 50 upright placed in middle of the lower plate held in vice. 2.4 tungsten and 2.4 filler with current at 135 amps on dial and this is what I got.
Cold alu right off the saw with a quick wire bruch to break the oxide.

 

[Richard.]

Looks good.
I'd be hotter (150 plus) and I'd be ploughing down it with a 3.2 filler. But that's the style I adopt for hefty plate. Especially an inside corner. It's a small coupon mind so 2/3 of the way down it I'd of backed off or speeded up

 

[Hood]

Looks good.
I'd be hotter (150 plus) and I'd be ploughing down it with a 3.2 filler. But that's the style I adopt for hefty plate. Especially an inside corner. It's a small coupon mind so 2/3 of the way down it I'd of backed off or speeded up

Seems like it is all down to style/technique then, and I was going like the clappers from about half way
The pic is funny, kind of looks like big ripples at the start and smaller as I progress, must just be the camera angle or lighting as it is pretty even all the way.

 

[Richard.]

Seems like it is all down to style/technique then, and I was going like the clappers from about half way
The pic is funny, kind of looks like big ripples at the start and smaller as I progress, must just be the camera angle or lighting as it is pretty even all the way.

It looks tidy enough to me mate.