aluminum gas

[chriswelds]

to ask another question on the aluminum welding. what is the best mix of gas to use. would like to try it with my hh135. just unsure of how to go about it.

thanks
chris

[Bob]

Hey,
here is one I know. The manual recommends pure argon, volts setting 4, wire speed 90, .030 wire for 1/8 Al plate.

I mail ordered my first argon, but recommend you find a gas dealer and visit ... would have saved a few bucks.

Plan on practice before you do anything for real, if possible with material, position, joint type as close as you can to what the real welds will be. I found the above a little too hot for me ... tended to sag thru if not burn thru, only avoided with fast travel speed too fast for me.

Bob

[Mike Sherman]

General rule of thumb is Argon for thin material, Helium for thick and combinations of the two for many different reasons.

[Mike Sherman]

Let me be more specific about Helium and Argon. One of the reasons I don't answer more questions on this board is that I don't always have time to give complete answers, and I really hate giving short ones because I end up clarifying what I said. Any inert gas could be used for shielding the arc in the GTA process, argon and helium are used because of their availability, economy and efficiency. A higher gas flow is required with helium than argon, but helium permits faster welding speeds and greater penetration. Deeper penetration is obtained with helium, because the AC arc in a helium atmosphere is hotter. The arc has greater stability when using argon. Arc penetration increases considerably when you add 10% helium to argon. For manual tig welding, most people prefer argon. Add helium only for a hotter arc. You can weld just about any thickness with either one. I would not worry about adding helium unless you are welding alot of .375 plate or above.

[Roger]

If you had spare Helium tank about you would try it and find it helps, but it's expensive and not common mix. Ernie Leimkuhler over at sci.engr.joining.welding news group has lots of posts about using Helium that can be found with google groups search. Some of his posts deal with welding aluminum with HH120. Post a question to him at that news group.