First (ish) welds on Stainless.

[Gizmo.Y]

I bought some 38mm SCH10 304 stainless elbows and Tee's to make a mock up Log manifold as a stainless training exercise.

35 amps. 2.4 309 filler.

Im happy with the results on the 2nd and 3rd weld. Not so much on the first. This is a test peice though, i doubt this will make it only a vehicle. I am aware of the "Sugaring" because this is not purged.

I found that 2.4 filler always stuck to the weld pool, would steping down to a 1.6 solve that issue?

First weld...

2nd weld.

3rd weld

1st (from other side)

3rd (from other side)

 

[500e]

3rd weld appears to have crack running through it ? is this due to no purge, shrinkage, or my old eyes

 

[Pete_88]

Looks like the steel could have done with cleaning up a bit more, could just be me though as I'm looking on my phone. The filler will be sticking as its cooling the pool too much, up the amps or like you say drop down to 1.6.

 

[eSCHEn]

As Pete says, rod is too large at 2.4mm for the amps. 1.6mm more suitable for sure.

The pools look okay but the colour of stainless tells the tale for heat and yours looks too hot and/or not enough gas (+post). What are your gas settings Giz?

Overall mate it looks good but I'll be brutal and say I know you're capable of neater beads, especially on a lovely vee'd fitup. I reckon with the right filler size you'll be miles closer as you'll be able to crack on faster with no other changes in setup. If that still gives you dull grey beads then try gas / post / amps changes.

^^^^ sorry that reads really harsh but it's not meant to!

 

[Gizmo.Y]

3rd weld appears to have crack running through it ? is this due to no purge, shrinkage, or my old eyes

I'm not sure...Will have to check when I get back!

Looks like the steel could have done with cleaning up a bit more, could just be me though as I'm looking on my phone. The filler will be sticking as its cooling the pool too much, up the amps or like you say drop down to 1.6.

I did clean it with brake cleaner. Quick wipe. But in hindsight it would of been better to get the wire wheel out...

As Pete says, rod is too large at 2.4mm for the amps. 1.6mm more suitable for sure.

The pools look okay but the colour of stainless tells the tale for heat and yours looks too hot and/or not enough gas (+post). What are your gas settings Giz?

Overall mate it looks good but I'll be brutal and say I know you're capable of neater beads, especially on a lovely vee'd fitup. I reckon with the right filler size you'll be miles closer as you'll be able to crack on faster with no other changes in setup. If that still gives you dull grey beads then try gas / post / amps changes.

^^^^ sorry that reads really harsh but it's not meant to!

Its not harsh at all! its why I come here. I want to make a living out of doing this, I need all the advice I can get!

Gas settings were 10lpm and 5 second post flow. 35amps ish ( I don't have an accurate way to set amps on my machine) I had started at 55 amps and blew a few holes at the bottom of the V

Struggling to get neat beats because of the filler sticking to the pool, moving the piece around. But the pool Is a mix of Dull and Shiny as it goes around (I Know Shiny is Very Good, Dull is "Ok" ?)

 

[eSCHEn]

You could knock the gas down a bit unless you're looking for p0rn welds, say 8lpm would be fine. Post flow at 5s is fine also but maybe eek it to 7s and bathe the last hottest part with it when you finish.

Personally at 35A I would be using 1.0mm filler but what's SCH10 wall thickness, two and a bit mm? I'd go in at 40 - 50A with 1.6mm filler. As it's vee prepped then you need to go quick! The reason why they're looking a bit cooked above is (and as always, IMHO) because you were using the right amps (55 ish) but the filler was cooling the pool too much and so you'd have to wait for the next one to fill up and so on. With slightly less amps and a 1.6mm filler if you go fast enough to keep up filling the leading keyhole that forms then you'll get a nice weld. Remember to set and check the bead size in terms of thickness as you go.

Backpurging is not something I'm familiar with but I would say you can use a backing strip where possible as well as a gas based purge. I'm not sure but I think N2 can be used which is a cheaper gas than Argon. SWK will be able to confirm/slap me dafter.

Brake cleaner I don't know if it's petroleum based or what but again SWK will be able to say. Personally again (lol) I use IPA, about £13 a gallon delivered. Remember to clean and dress the weld area with a wire brush/wheel or whatever as well as cleaning it down afterwards with a solvent. Strictly speaking I'm not sure it's needed on an exhaust system but put it this way - it's not going to make the job any harder or poorer in finish.

And above all remember - IANAW (I Am Not A Welder) ! X

 

[Gizmo.Y]

wall thickness is roughly 3mm. I havnt got any more test pieces unfortunately. will take the advice on for when I get another lot in stock.

 

[Richard.]

Your welcome back Giz if you want to do another 4 hours and we can go through some DC welding as iirc we only did Alu last time and your doing well with that.

 

[Gizmo.Y]

We did some Stainless, only roughly 15 minutes before I left on some thin sheet. will have to see when we can get together again.

 

[Richard.]

Yeah just let me know. I'm sure I can help. Got some tube too in 304 so you can have a bash at what you like. We can do some purging too and I can show you how I purge different things for nice full pen stuff.

 

[Gizmo.Y]

I checked that world, no signs of cracks all all. could be the angle of the picture.

 

[500e]

The eyes have it then

 

[Richard.]

Ok.
As established your 2.4 filler is waaaaaaaaay too thick.
You may as well throw a few bricks in that pool while your on.
2.4 filler is 120-150 amp filler.
35 amps is a little cold as Eschen said go for around 50 and use a 1.2. I know your practicing but there are more suitable grades than 309(Dissimilar) for that.cheaper ones too like 308.
Any way your welding could do with a kick up bottom and get the travel speed up. Those runs are far to wide they look almost weaved which is a result from the low current and filling with a lump of rebar. The slow travel has increased the heat input which is why they look dull too. Id also say you haven't kept a tight arc either. Which is why things have spread wide.
I could be wrong but have you also been welding that tube past the top dead centre ie down hill.
The runs look like they have dropped which happens when when you travel up and go down the other side. Always weld to 12 o'clock then stop. Unless you can rotate it while welding.
Finally make sure that tungsten is lovely and pin point sharp. Narrow point 2-3 times the diameter in length. Gas flow 6-8lpm. (Any more is a waste through a small cup) post flow I do at 6 seconds for 1mm thick and add 1 second for every 1mm above that.
Every thing below 1mm I do at 5 seconds minimum.
These are my thoughts on it mate. Hope it helps.

 

[Gizmo.Y]

I had been welding from 2 till 10 ish. So half up, half down. I will take the Tips on board. Be nice to find a cheap UK supplier for this type of stuff, as i will be using alot of it.

I am using 308 filler, must be a typo in the top.

 

[Richard.]

2 till 10 ish. So half up, half down.

Aha....... I knew it. Slap on the wrists there. Can't hide such things from me.

 

[Brad93]

Sound advice from Richard there. If the pipe isnt 'in position', weld from 3-12 then rotate and do the same again.

 

[Gizmo.Y]

Its all a learning curve

 

[Richard.]

Its all a learning curve

It is. And welding round small tubes with GTAW is certainly something that will test you if your new to it.
Why not practice your stainless on some easier joints much like you did in aluminium for a while.
Practice what's needed to perform perfect runs on plate. Understand the requirements needed from you then transfer it to a pipe once you've got it to a fine art.
You've jumped a little quick imo.

 

[Gizmo.Y]

Its getting the scrap to test though. Unfortunately i don't have any local suppliers. these bends pictured above i got from China for £4 a piece. but its waiting 2 weeks for them to arrive.

 

[Richard.]

Its getting the scrap to test though. Unfortunately i don't have any local suppliers. these bends pictured above i got from China for £4 a piece. but its waiting 2 weeks for them to arrive.

Giz all I do for my tuition sessions is buy offcuts. I don't use my stock unless I have too. There are lots of places around the UK (I'm sure local to you too) that have big guillotines chucking small offcuts away daily. Ask them if they will sell them to you, build a relationship. Tell them your learning and anyone decent will happily help you out. I pay £1.50 kg for SS off cuts from my guy. He usually keeps some nice bits for me which I chop to size at home. You need to get out there and ask the questions. Most of these company's bin the small bits because they have no value or use but for practice and my teaching they are perfect. You never know you might Get some tube offcuts too.
Don't buy metal from China. There is enough of that s##t Metal here already.