Noob at TIG welding, help?!

[Keegan Mccormack]

Hi All,

I’ve just got all the stuff I need to start welding. I’m mainly going to be welding stainless steel tubing. I’ve ran some practice welds today and honestly, they look crap. I do get penetration through the pipe but the welds on top look rubbish. Every time I finish my pass they seem to go grey, flake up & just look pants.

I’ve attached some photos for you guys and also listed specs/consumables.

TIG Machine: Cheap eBay one (Called TIG-200C)
Electorode: 1.6mm RED tip
TIG Torch: CK #9. Using a 10 cup, with a normal 1.6mm collet body & collet. Standard supplied heat shield too.
Filler rod: eBay stuff. 308L. 1.6mm thick.
Stainless Steel pipe: T304. 1.5mm thick.
Gas flow: 6LPM

Any help would be greatly appreciated. First time touching a welding torch so be gentle. If you need any more information, let me know.

 

[willie.macleod]

What gas are you using?

 

[anto44]

What amps are you running? The welds look very hot, so either less amps or increased travel speed. The grey appearance and sugaring on the inside are due to lack of gas coverage, for starting off a no. 7 cup with a gas lense will work better and that will improve the appearance of the weld. To eliminate the sugaring on the inside of the pipe you will have to purge the pipe.

 

[Paul.]

You have a gas problem, a no.10 ceramic is quite big and will need more than 6lpm, you would be better of using something like a 7
Current looks to high, and /or the arc gap is too wide, either way its far too hot
Have you read the tutorial, its all in there. https://www.mig-welding.co.uk/tig-tutorial.htm

 

[Keegan Mccormack]

What gas are you using?

I'm using pure argon gas.

What amps are you running? The welds look very hot, so either less amps or increased travel speed. The grey appearance and sugaring on the inside are due to lack of gas coverage, for starting off a no. 7 cup with a gas lense will work better and that will improve the appearance of the weld. To eliminate the sugaring on the inside of the pipe you will have to purge the pipe.

Running around 60AMPS. I can't seem to build a puddle as soon as I start the torch. Could I try a 7 cup without a gas lense for now? I'll order a gas lens for my torch and try that when it arrives. I'm not going to purge these yet as it's just a test for now.

You have a gas problem, a no.10 ceramic is quite big and will need more than 6lpm, you would be better of using something like a 7
Current looks to high, and /or the arc gap is too wide, either way its far too hot
Have you read the tutorial, its all in there. https://www.mig-welding.co.uk/tig-tutorial.htm

I'll try a 7 cup and see what I get. If I wanted to use the 10 should I up my gas to 10lpm or so? Thanks for that, i'll have a look at that now actually.

 

[BigOz]

Where you are melting the whole way through without protecting the back of the weld you will be getting contamination through the weld to the front side, if you want nice results on a full pen stainless weld you need to protect the backside of the weld with the best option being a shielding gas purge or if that is not possible a product like Solar Flux or a backing material like an aluminum block.

Try not melting the full thickness and you should be able to get a much better weld appearance on the front with the setup you have.

A test I like to do after swapping a bottle or starting an important job is set a long post flow then hold the torch vertical and unmoving over a clean piece of reactive material like stainless or titanium initiate the arc and let a small puddle that does not penetrate the whole way through to the back form then stop the arc and stay still with the torch in the same place until the post flow ends. If all is well you should have nice silver shiny metal spot where the puddle was and no oxidation where the gas protected the metal.

 

[Munkul]

it's thin stainless, and plain 60 amps is probably too much unless your TIG skills are on point (i.e. very tight arc and fast travel speed). Remember you'll use some of that heat when you're actually making a joint with filler, so it won't look quite as bad as it does with a plain bead.

As others have said, the fact that you're burning heavily through into the inside with no purge, it's pulling oxides back through into the topside. Lighter amps will help this, but to get a perfect weld you needs to purge the inside full stop.

 

[Paul.]

A test I like to do after swapping a bottle or starting an important job is set a long post flow then hold the torch vertical and unmoving over a clean piece of reactive material like stainless or titanium initiate the arc and let a small puddle that does not penetrate the whole way through to the back form then stop the arc and stay still with the torch in the same place until the post flow ends. If all is well you should have nice silver shiny metal spot where the puddle was and no oxidation where the gas protected the metal.

Known as a spot test, I described it here with some photos a long time ago https://www.mig-welding.co.uk/forum/threads/just-got-a-new-tig.27276/page-2#post-301703

 

[Rrobson]

As above, no back purge or backing block on thin stainless is going to end in tears.

When welding if your struggling with too much penetration you can lean your torch back a bit which will help. You also don't want to be reducing the amps too much, 60a probably isn't far away. If you go a lot less yes you'll get less penetration but you'll also be putting loads more heat into the part because your travel speed will be really slow to maintain a puddle.

It would help to get your hand in with some mild steel. This will get you practicing travel speed, wire feeding, torch control etc and put you in a better place for stainless because it certainly isn't the easiest material to start tig welding on!
Otherwise not a bad first attempt

 

[Keegan Mccormack]

Thanks for the advice everyone. I've taken a lot on board and got myself a few other bits to test out on. I'll be trying everything you have all recommended so thank you very much!

Just a few question, I've got a dual flow meter as I've got another bottle of Argon that I bought for when I do start purging (After I can weld decently enough). I thought purging was just to stop the sugaring on the inside of the pipe? Didn't think it had any effect on the outside weld look/quality.

I've ordered a few different torch accessories for my series 2 CK #9 torch such as different size collet/collet bodies, different cups etc. What i'm currently using, is that ok for this type of application? Or should I size down/up?

Lastly, In the images I've attached my welds seem to be eating into the pipe, rather than building up on top. Only way I get it to build is to ram A LOT of filler into it. How do I stop this from happening? Will this be somewhat sorted after I've sorted my gas issue & done some other tests?

 

[Barking Mat]

Start on something flat and practice running a bead!

Don't run, before you can walk, mate!

 

[Keegan Mccormack]

Some new parts arrived today so I gave them a test. Below is a few runs on a #7 cup at around 6lmp & 50amps. Also a #6 cup at same gas flow and amps.

Feel like the 6/7 cups work a lot better for me. Any tips on my gas flow. There’s a mix between a few slow runs and a few faster runs. Seems running faster works better too.

I’m going to get myself some flat pieces of mild steel to test out on as mentioned above. Do I need anything else or is my setup good to weld it? I’ll do some research but any tips from you lot would be much appreciated.

Thanks for the help so far guys! Onwards and upwards.

 

[mtt.tr]

Practice on mild steel and follow the forum guide, you end up wasting time if you haven't got the basics. Once the fundamentals are got everything else comes far easier.

 

[Richard.]

There is still a contamination issue happening here. Could be something simple like your arc gap being too long or something more complex like a gas leak in the system.
your heat input is way too high as well. The welds are very sunk and grey I don’t think the tube is helping much I’d suggest you stop persevering with it.
You want some flat plate 2-3mm
Some 1.0-1.2 filler
No 7 cup.
Tight arc of 1-2mm
Sharp tungsten
Start at 25amps per 1mm and go up or down to suit. your machine probably isn’t putting out what’s displayed as a lot of cheaper ones understate drastically so a bit of trial and playing till you find your spot.
Tight arc is key. Without that you’ll never progress.

 

[Keegan Mccormack]

There is still a contamination issue happening here. Could be something simple like your arc gap being too long or something more complex like a gas leak in the system.
your heat input is way too high as well. The welds are very sunk and grey I don’t think the tube is helping much I’d suggest you stop persevering with it.
You want some flat plate 2-3mm
Some 1.0-1.2 filler
No 7 cup.
Tight arc of 1-2mm
Sharp tungsten
Start at 25amps per 1mm and go up or down to suit. your machine probably isn’t putting out what’s displayed as a lot of cheaper ones understate drastically so a bit of trial and playing till you find your spot.
Tight arc is key. Without that you’ll never progress.

So, after waiting for some bits that have finally arrived I’ve given it another go. This time, a lot better.

These welds were done on mild steel plates, 1.0mm filler rod, #7 cup @ 6lmp and 75amps. I seem to be getting a lot of build up, seems to be too much filler & moving too quick so I’ll practice that some more.

I’ve left the pipe alone until I get better at this. What’s all your thoughts?

 

[Barking Mat]

All a question, of speed, heat, amps I think, looking promising, someone with more experience and knowledge, will be along...

As Nemo, said, just keep swimming,....