Someone school me on why there are specific inert gases for welding stainless, aluminum, steel, etc? Like why do you need a tri-mix for stainless as opposed to being able to use argon?

because

Mild Steel= C25 or Co2
Aluminium = 100% Argon
Stainless = Trimix
High-Nickel = 100% argon

because

Because he has a red star, you don't and neither one of you wanted to search :flipoff2: :laughing:

because

wow Dug, your a regular fawking Einstien aren`t you :laughing:

Mild Steel= C25 or Co2
Aluminium = 100% Argon
Stainless = Trimix
High-Nickel = 100% argon

I know "what", gases are used with each metal. I want to know "why", they are specific "to", each metal.

Stainless needs some oxygen to flash/consume the carbon depoit, don't know about others.

Quick and easy:
http://www.bc4x4.com/tech/2002/gases/

Because someone smarter than me took the time to figure out what works and what doesn't work... :flipoff2:

Quick and easy:
http://www.bc4x4.com/tech/2002/gases/


That was helpful, thanks.

I am bumping this.

I am curious about TIG.

I thought TIG was almost always 100% Argon, but I had a gas guy tell me I needed Trimix to do some disimilar metals (SS to Copper).

Is this correct or do I use argon?

I thought TIG was ARGON and Heliarc (sp) was helium.

THANKS

Never done copper to stainless before but I've done a lot of cast iron to steel or stainless with bronze filler and straight Argon. I've also done a bit of brass to steel with bronze filler and straight argon. I wonder if either of those would have welded better with tri-mix?

I know "what", gases are used with each metal. I want to know "why", they are specific "to", each metal.

Oxidation control.

I thought TIG was almost always 100% Argon, but I had a gas guy tell me I needed Trimix to do some disimilar metals (SS to Copper).

Is this correct or do I use argon?

I thought TIG was ARGON and Heliarc (sp) was helium.

You're correct. Normally, straight argon is used. Helium is used to increase penetration, increase speed of welding, and for high conductivity materials such as copper and aluminum.

Heliarc is actually a registered trade name - so Heliarc®. TIG is "tungsten inert gas" and GTAW is "Gas Tungsten Arc Welding" - either of which is the generic name. When it was developed in the 1940s, it was being used for aircraft welding - aluminum, magnesium, and stainless. So they were using helium. It wasn't until later on that they started doing more steel welding with argon.

[/history lesson for the day]

You're correct. Normally, straight argon is used. Helium is used to increase penetration, increase speed of welding, and for high conductivity materials such as copper and aluminum.

Heliarc is actually a registered trade name - so Heliarc®. TIG is "tungsten inert gas" and GTAW is "Gas Tungsten Arc Welding" - either of which is the generic name. When it was developed in the 1940s, it was being used for aircraft welding - aluminum, magnesium, and stainless. So they were using helium. It wasn't until later on that they started doing more steel welding with argon.

[/history lesson for the day]

I thought the process named Heli-Arc was developed to allow for welding titanium for airframe construction.

As I understood it, it was either Grumman, McDonnel Douglas, or Boeing that invented it to assemble one of the early spy aircraft. Edit-it was Northrop aircraft

Again, as I understood it, true Heli-Arc is conducted in a completely inert atmosphere and the shielding gas is used to dampen any oxidation that might take place due to the chemistry of the materials under welding conditions.

There hasve been some HUGE "glove-boxes" on eBay that were supposedly surplus from aircraft manufacturing and Heli-Arc welding.

I am bumping this.

I am curious about TIG.

I thought TIG was almost always 100% Argon, but I had a gas guy tell me I needed Trimix to do some disimilar metals (SS to Copper).

Is this correct or do I use argon?

I thought TIG was ARGON and Heliarc (sp) was helium.

THANKS

Tri-mix has CO2 present, although in small amounts. CO2 will dissociate at the high welding temperatures, and upon recombination, will oxidize the weld metals. (and create higher welding temperatures)

I think I explained it correctly, but anyway, here are some good links

http://weldingweb.com/showthread.php?t=44454
http://content.lincolnelectric.com/pdfs/products/literature/c4200.pdf

-G-

Heli-arc is tig. It's a trade name and still in use on the last Esab tig welders I saw.

Helium was used at first (Thus the Heli-) then they started using Argon on general stuff.

Helium or a Helium/Argon Mix is still used, because Helium allows for a hotter arc. It doesn't make the arc hotter like CO2 does on a MIG (CO2 is a reactive, not inert, gas), but the arc loses less heat as it crosses the Helium vs. the Argon.


-James

I won't touch the subject of MIG gas mixes with a 10 foot pole - It's a debatable topic and there's a lot of disagreement on what works best for what.

on TIG welding straight Helium...
100% helium is not fun to weld with. It's TOO hot for most aluminum work, can make starting a bitch, and the arc tends to be very unstable. Stuff is also way too expensive to run straight on a regular basis (Not only does it cost more, you need about 3x the cfh of Argon). It works out at about 7 to 8x the cost of straight Argon. If you have a flowmeter with the scale calibrated for Argon, "25 cfh" is actually "80 cfh". At the recommended flow rates, you will burn through a bottle of pure Helium really fast.

On the other hand, Ar/He mixes are awesome. You can do some absolutely amazing shit with pulse and a 25% mix. Every welder should try it at least once. It gives you most of the advantages of Helium, without the arc instability problems and at a much lower cost.