Hey guys,

I just got a Miller Dynasty 200DX and a weldcraft wp20 torch for it, and my previous experience I learned on a harbor freight tig... which honestly wasn't that bad!

I have some questions here..

1) I have about 150 or so 8th inch red band tig rods and I honestly can't tell the difference welding steel vs aluminum with them could someone comment on this.. compared to the green band ones for aluminum.

2) When I tig aluminum I have found its really hard to get a puddle without creating a huge puddle.. I'm testing on 8th inch aluminum sheets just scrap. "Is the amount of amperage really really narrow for no puddle vs too big of a puddle?"

3) suppose you use 75/25 to tig with what would happen?

I'm about 3 hours with this new tig just trying to learn as much as I can, but it seems like so far I can make really really nice welds with steel, its the aluminum that's kicking my butt could someone give me some pointers? I tried the settings recommended for aluminum and just messing with the DCEP/DCEN ratios, but AC is really really noisy compared to DC... I don't know I'm learning.


--Aaron

 

For starters you should be reading the literature a lot more than you have.
You have to post pictures and tell us your exact settings for best results.
What is your balance set to?
Start with 70%, and play with it between that and about 85%.
Did you go through the manual to check your default AC wave shape?
My 350 was soft square wave,and I didn't like it right away. Advanced square wave is better for most applications in my opinion.
What frequency are you using? The lower the frequency, the bigger the puddle.
Start with 120hz, and go up 20, try it, etc. Higher frequency AC welding is loud for sure.
How are you prepping the tungsten? What are you prepping it with?
What are your amperage settings? .125" aluminum should be around 125-150 amps.
You can't use 75/25 mix to weld aluminum unless it's a helium mix with argon.
Don't use the pure (green) tungsten on your dynasty ever.
The red thoriated will work, but it's not optimum for aluminum. Lanthanum doped tungstens work far better in my experience.
The more info you give, the better this place can help. HT is full of excellent welders willing to help given the opportunity.

 

Congrats on your new purchase. You'll love the machine more and more as you use it. First and for most, as 9bells mentioned, read the manual front to back and keep it nearby as you'll be going back to it often.

1) 1/8 tungsten is pretty big for what your welding but it'll work. For aluminum I use a 3/32 for thicknesses from 1/8" at home and 1/4" at school. Red (Thoriated) tungsten, I would never recommend on aluminum, though you can still weld with it, the tip doesnt ball evenly to my liking. Green is not recommended for use with inverter machines, not sure why but I never bothered to try it and find out. I've use arc-time hybrid tungsten for everything I weld and on occasion 1.5% lanthanated as 9bells recommended, works great.

2) Are you easing into the peddle as you strike your arc or just slamming the pedal? Within the machine setting, Miller has created to setting for each size of tungsten used in order to help with arc starts, maybe you can give that a try. By default it it set to 3/32.

3) 75/25 is big no no for tig. See link
http://weldingweb.com/showthread.php?t=43982

Since your just starting out, I would say just to leave the machine between 65-75 on balance and 105-115 on freq as those settings would be good all around. Once you get better you can start dialing in the setting to get the bead shape your looking for. The machine is set to Soft Squarewave by default which I is fine. Just like the balance and freq, you can play with the wave shape later.

 

9 Bells
Thanks for your info!

Yeah I read the manual on a couple settings at work yesterday and setup the machine according to how it says for 1/4th aluminum.

I have a bottle of chemical sharpener, since I read online the inverter machines have a way of welding aluminum with a sharpened tip vs a balled tip, it makes it much easier on me.

yeah 125-150 I was using like 135 and it seemed to start to puddle the aluminum about 3/4ths way down on my pedal I was able to make a couple "OK" passes considering its the first time ive welded aluminum, but by no means are they excellent, good for 1 hour of messing around though no doubt.

In the next couple of days I'll add to this post with photos... but be easy on me I'm new to tig!

SlowReaction,

I just have a lot of 1/8th inch rods, I spoke with a friend who has been using a tig a while and mentions to me that a larger rod will last longer even though its not the correct one to use, although once I know more about my machine Id imagine that a correct rod will last just as long right?

I am easing into the pedal watching exactly what happens before it starts to melt during and such.


I was thinking about picking up some of the Arc-Time ones I saw advertised a while ago.

I do believe it's going to be some time before I fabricate some headers for my h22 hatch

THANKS FOR THE FEEDBACK!

--Aaron