Welding Tips and Tricks

Hey guys I need some help ! I am proficient at tig welding steel and stainless steel. I am trying to learn aluminum now but for the life of me I cant get it right. Ive been using a precision tig 375 for 1/16 alum, min amps 20 and max amps 90, 1/16 pure balled tungsten and 1/16 filler and the machine set to AC. Now I cant get a decent puddle going. It seems like I have to wait forever for the puddle and thats with the pedal maxed out, I tried turn the heat up but it turns out to be to much. If I get a puddle going it gets so hot that it just melts away or it cools off and then no puddle. So the result is the weld is very hazy with no definition. The arc is also really loud. So Im wondering if someone who has the same machine could tell me what settings they would use so I can start from there and see what happens. I dont know what year this pt 375 was made but its a transformer machine so there arent any fine tuning controls, just a high frequency knob on the bottom right side of the housing. Thanks in advance for any help

I never liked that machine for Al, but,

You had the right idea, more heat. The trick is on you...

Use the extra heat to get the puddle you want, back off on the pedal. It's a "finesse" thing with that machine.

Also, lose the 1/16" tungsten. I can do beer cans with that. Go 3/32.

Thanks, I'll give that a try and see what happens.

I jumped up to a 3/32 pure tungsten and that helped tremendously. Now I bought some lanthanated tungsten to try on aluminum but from what Im gathering you can only use pure tungsten on transformer machines, you need inverter style machines to use different tungsten for aluminum. Is that right?

Newer square-wave machines, including the 375, can use alloyed tungsten. It's the older sine-wave machines that don't tolerate it well. You get the most benefit with an inverter, but alloys are still an improvement for the 375.

You do have to watch your arc-balance closely, to avoid the tungsten splintering and spitting. I set mine as far toward "penetration" as the weld will tolerate, and put a little extra effort in pre-cleaning the weld right before I start.

Steve S