Aluminum tig settings help

[TJsparks]

First time tiging aluminum. Using an older syncrowave 250. I have some pure (green) tungsten. Need to put some 1 1/2X1/8" angle together. What freq. setting should I use? 0-100%. Arc balance 0-10, creater time, and there's a 3 pos. high freq. switch. Any suggestions would greatly be appreatiated. Thanks ,TJ

[Agades]

AC current
high frequency - continuous

are you using a remote (foot control or finger control)??
if you are
put current and contactor on remote

shut off crater fill - you can do that function with your remote
AC balance on 60-70% EN

I personally dont like pure tungsten, it doesnt handle heat as well as alloyed electrodes, but it will work just fine


weld fairly hot and move!
try not to just soak the heat into it

[TJsparks]

Using a foot pedal and on remote. I'll give it a try and post some pics. Thanks, TJ

[TJsparks]

Here's a pic of some stringers. It sure does move fast. I started a pool,backed up and dipped, Jab+stab. Can't see much behind the cup, kina hard to keep the pool width consistant. Top stringer was at 150A,bal 70%,1/8' 4043. Had to mash the pedal to get started. the rest I went to 200a and backed of the pedal. What kind of motion do most of you use?

[Anti-GMAW]

You need more heat. Same motion as DC just hotter and faster and a lot more rod. It's not the motion that’s different, it's the puddle. You have to handle it differently than steel. Most people who are new to aluminum don't use enough heat. There so used to using lower heat on DC that they don't think the necessary amount of heat could possibly be the correct amount. Aluminum acts as one big heat sink, so even though aluminum melts at a lower temperature than steel it still requires more heat. It dissipates heat almost as fast as you put it into the metal. Unfortunately all this required heat has a drawback. As soon as you get it hot enough it's nearly to hot. SO MOVE FAST! Another thing is when aluminum gets that hot it shrinks more than it expanded when it cools off. So you need to add a lot of rod. If you don't it will crack when it cools. Another thing is when adding rod don't slow down to heat it up enough to melt the rod. You don't have the same kind of play that you do with steel. You need to be welding hot enough to begin with. Always make sure your puddle is established before you move an inch! If you need to increase your heat then use your pedal, don't slow down! As far as balance control goes that’s what cleans your metal. Aluminum has an oxide layer on it that that melts at a higher temp. than the metal. You need to clean that layer of with a stainless steel wire brush. (Absoulutley has to be stainless!) It takes a lot of work to get it off and it reforms almost instantly so don't try to clean more than 6" at a time. The reason you have to use AC to weld aluminum is because it's able to clean off that oxide layer. (But it's not able to get it all so you still need to brush it.) As the current switches polarity’s it bust through the oxide layer. The current comes down from the tungsten into the metal heating it up, then it switches polarity’s and goes up into the tungsten. When it goes into the tungsten it comes up through the metal and smashes its way through the oxide layer. Because it's going into the tungsten it creates heating in the tungsten and causes it to ball up. Is what balance control does is set the amount off time for the AC half cycles. If you want more cleaning turn the balance control up, if you want more penetration turn it down.
Hope this helps

[TJsparks]

Thanks Guys. Every litte bit helps. I'll keep on practicing. More heat,filler and move fast. What about the frequency switch? I don't have the manual for this machine. It's a 3 pos.toggle, center off, up is an upper sinewave with a small bar in front of it and down is a bold sinewave . TJ

[fun4now]

looks like you are on the right tract, it just takes time to get every thing even and looking nice. there is no substitute for time on the torch here. some like to play the radio and get into a rythem. its all about consistancy now. heat dab move heat dab move. its best if you can keep things roling along using the filler to cool the puddle so you are running hot enough to melt threw but keeping it under controle by adding filler. this is where aluminum get tricky as it wants to melt out on you and you have to have the filler ready to go. done right its just a fast series of dabs. if its at all possible find some one that can show you how its done, seeing it done right realy speeded up my lerning process. although i am still lerning to get evey thing even and looking like a nice stack of dimes or whatever you want to call them, consistancy is by far the hardes and only time can get you that. stick with it it will come in time.

[Engloid]

You're melting your wire with the arc, rather than with the molten puddle. In other words, imagine having a large vat of aluminum. If you throw a filler wire in it, it will melt quickly. This is what you want to happen in your weld. You don't want the arc to melt it.

What this will do is keep your weld from looking so lumpy and inconsistent. As you weld, keep the width of your bead consistent. When you add filler, the only change you should see in the puddle is the elevation of it...which will put the ripple at the back of it.

[TJsparks]

Thought I had er down (on the nice open flat stringers) then I started on my project and it all went to he''. Doing a 1 1/2"X1/8 inside lap joint. When I got it hot enough to move my tungsten dripped off into the pool. Using 3/32 pure at 200a, almost full pedal to start, and then backin off a little. Should I go to 1/8" pure?

[handirod]

Hey guy's

Not to change the subject, but earlier, one of the guy's mentioned that he didn't prefer using 100% pure tungsten when welding aluminum & I've heard that before. What kind of tungsten do you guys prefer?

I've gained allot knowledge just by reading through these threads because I can tell there’s allot of experience from the guys responding to the questions and you can't get that information from a book, just from time behind the hood & I thank you all for sharing!

Rodney