Using helium as shielding gas

[HMB]

as above. Has anyone done this with Alu?

 

[NickyEng]

I've used it. You don't usually use pure helium, a helium / argon gives the best of both worlds - the higher thermal conductivity of the helium and the cleaning action of the argon.
It's good if your welder is operating at full power and you require more heat energy In the weld, the higher thermal energy from the helium let's you cheat a bit as such.
Also increased travel speed is an advantage.
One disadvantage is it horrendously expensive

 

[HMB]

Ah but I got 5/6 300bar tubes taking space up

 

[Pete.]

Ah but I got 5/6 300bar tubes taking space up

Store them. They will have great value in time to come.

 

[NickyEng]

You have done well then pal... It's costly stuff

 

[HMB]

I know

I've got he/ar mix on my tig but got a iveco fuel tank to fix tomorrow and speed (?) is of the essence or I'd tig it

 

[HMB]

You have done well then pal... It's costly stuff

4.5ppl dive grade 99.999%

 

[backpurge]

Helium is hard to ionise so arc ignition and arc stability with pure helium is always an issue, as has been said already it needs mixing with argon then you can use it with MIG and TIG on ally and you will get far, far better results than with pure argon

 

[dan.taylor.1]

I know little about tig but I'd reckon on a fuel tank being rather thin and as I understand it helium adds penetration due to its higher thermal conductivity or something so might be too much heat for this ally?

 

[backpurge]

I know little about tig but I'd reckon on a fuel tank being rather thin and as I understand it helium adds penetration due to its higher thermal conductivity or something so might be too much heat for this ally?

It doesn't work quite like that, because you are making the weld pool more fluid it allows you to travel faster, but because you haven't increased the parameters your heat input comes down. We have customers welding below 1mm thick ally using a variety of helium mixtures

 

[weldgauge]

are you just going to patch up the holes or replace a section? just curious.

 

[HMB]

Replace the section

 

[Richard.]

It's lovely on stainless too.
I really should invest in a cylinder for myself. I use it at work a lot and it's certainly a better mix than argon alone.

 

[premmington]

Heliarc, is how TIG welding started.

I have never had a go.

 

[HMB]

Other than the pita feed problems with 1mm 5356, it welded real nice

 

[WorkshopChris]

Have never used it with tig. But BOC used to do a few mixes especially for stainless mig. Expensive but produced a lovely weld.

 

[Richard.]

Have never used it with tig. But BOC used to do a few mixes especially for stainless mig. Expensive but produced a lovely weld.

Agreed. On stainless Mig it really is on another level. Through a lovey pulsed Mig set it's awesome.

 

[WorkshopChris]

Its about 10 years or so since i was welding in my day job but from memory we also used a blend of helium/ hydrogen with argon and may be a touch of co2. Welding Stainless sparge pipes used in paint tanks all low pressure.

 

[backpurge]

Backpurge is that MIG or TIG?

Both but the effect is more noticeable with TIG to be honest