Helium Gas tig welding

[hankron]

Hi can anyone tell me if an argon gauge will fit a 10kg Helium bottle please,
I am just buying a Tig welder so i can weld my Model locomotive Boilers.
I have bought a 200 amp tig set ac/dc but need to use Helium gas for hotter welding.
Copper is 3 mm thick also will i still need to heat copper red first as with Silver steel 55% rods with Gas
Many thank's
Ron

 

[BrokenBiker]

You need to weld hotter than 200 amps on 3mm copper? Are you sure? I've never welded copper before, but that seems a bit excessive

 

[TechnicAl]

Pure Helium?

 

[Maker]

You need to weld hotter than 200 amps on 3mm copper? Are you sure? I've never welded copper before, but that seems a bit excessive

I think it depends on how big the part is because it will wick the heat away very quickly.
I've tried it and it was very very hard, albeit I am a novice, it was thin and I don't have helium or a footpedal.

 

[mechman]

Pure Helium?

If you weld copper at 200 amps I would think you would have to have your elbows in starting blocks,unless you mean that's the max range of the machine youre using

 

[Maker]

For 200 amps Helium, I hope you have a water cooled torch, that's gonna get toasty. It might be wise to get stick welding gloves (or watercooled gloves).

 

[pedrobedro]

Might not be far out at 200amps according to TWI but they recommend argon/75 helium mix with a 50° C pre-heat.

 

[ben8vgte]

Hi can anyone tell me if an argon gauge will fit a 10kg Helium bottle please,
I am just buying a Tig welder so i can weld my Model locomotive Boilers.
I have bought a 200 amp tig set ac/dc but need to use Helium gas for hotter welding.
Copper is 3 mm thick also will i still need to heat copper red first as with Silver steel 55% rods with Gas
Many thank's
Ron

Are you using the TIG to weld them or as with the gas 55% silver solder? With either process you'd still need to reach the same temperature if you using the silver solder, if you were welding it then you wont need to get the joint up red heat first.

 

[Shox Dr]

SIF No8 works well, there's few pictures of some I did on 2" plumbing pipe in my Albums . I was surprised how little amps were required....Of course I forgotten the settings) but it was lower than I was expecting.

 

[agrimog]

your buying a tig to silver solder model copper boilers.....why, with a tig you can actually weld the boiler, homogenous weld, copper to copper which will be a lot stronger and require a lot less hear, do a little research into the technique

 

[hotrodder]

Hankron never said he was planning to silver solder with TIG, he asked if preheat for welding would be the same as if using 55% silver steel (presumably a typo for solder?) with oxyfuel. With the infomation we have from the OP the TWI link Pedro posted is about as detailed as possible

As Al asked are we talking about pure (99.996% aka grade 4.6 or better) laser assist/welding grade helium? If it's balloon helium it won't work at all since that's a mix of air with enough He to make balloons float. Helium cylinders typically use the same BS3 (5/8 BSP RH) valve connection as argon etc but obviously flow meters calibrated for argon and argon/CO2 won't read accuratly

Argon helium mixes are generally used over straight He for several reasons to do with arc stability and arc starting due to the higher ionisation voltage. While ArHe will be much nicer depending on the size/mass of the parts and amount of preheat you might get by OK with straight argon... certainly be cheaper for learning with unless you've got a free source for pure helium