TA 185 Welding Problem

[rmbates]

I'm trying to weld a Tee Joint using 5052 Aluminum and 4043 stick. One piece is 3/16" being attached to 1/8". Using 1/8" 2% tungsten and argon. Cleaned all surfaces with grinding disc. Arc starts fine but will only hit one piece of material...not right in the middle. I either burn through or the bead just attaches to one piece of metal. Using a foot pedal and heavy pressure to get started but then back off some to avoid burn through....set on Weld, not step. Got machine turned all the way up to 185, pre flow 1 sec and post 5. Pressure set on 23.
Took the same material to my shop where I have a synchrowave 250 and ran a perfect bead on first try. There I had machine set on 220 but only used about 2/3 of the pedal. Difference was that a good wide arc shot right into the middle of the joint and formed a good pool. I'd rather use my home machine as I have a large set-up table there and am working with a lot of bends and round surfaces. Thinking that there's just not enough power in the TA to handle the 3/16" part of the metal although it will burn right through in no time at full pedal.
Any ideas or suggestions? Thanks

[DrIQ]

If you use the following set up you should be able to do the job with the TA-185 as well as the SW-250.

Set preflow at .5
Set initial current at 20
Set the AC cleaning at 25-30 (wave balance)
Set the AC frequency to 60 HZ ( matches the syncrowave)
Set the post flow to 10 sec.

Grind the tungsten to a point like you would for steel but put a flat on the point 1/16" or less.

[SundownIII]

DrIQ,

Think you may want to go back and review those recommended settings. Think the OP is going to have a "little" trouble welding 1/8" aluminum at 20A.

Personally, I'd suggest:

Set machine at 125A. Control heat with pedal. You'll need to back off a little as heat builds in the material.

I'd use a 3/32" 2% lanthanated tungsten if it were my choice.

I'd set my machine for about 75-80% electrode negative (think the TA's setting are backwards from the Sync machines)

I'd use as large a cup as I could get in the joint (probably a 6 or 7)

A higher HZ (say 100-120) will better allow you to focus the arc in the root of the joint. (Higher freq=tighter arc)

.4-.5 preflow is fine. I'd set my flowrate between 16-20 CFH.

3/32" filler.

Give it a try and let us know how it turns out.

[DrIQ]

Sundown III

If you read my settings you will note the 20 amps is initial current. The 125 Amps will be a little cold for the 3/16" material and may make melting the 1/8" material worse, starting at the 185 amp setting and focusing the heat on the heavier material initially should work better. The higher frequencey will focus the arc more but in my experiance with the TA-185 I had better sucess with the setting I suggested on materials in the 3/16" range. I normally would use 80 HZ on 1/8" and a max of 100 HZ on 1/16" or less. The tungsten is more of a personal preferance but in the testing I have done the 2% thoriated seamed to hold the tip better.

[Brand X]

The TA is not really too picky about tungsten types other then pure. Might want to find some 4% thoriated, to see if they hold their shape better then 2%

The lower the freq. the easier to get the puddle wet with the smaller units. If you clean your aluminum real well you can run less wave balance. (more DC -) Maybe 15 or 20. It will also help in getting the puddle wet and also help keep your tungsten's shape. Which should not be a very sharp point. Remember the arc does not come right off the tip, it comes off at right angles to the face of the grind.

[rmbates]

Thanks for the suggestions guys. I'll make some changes to my setup based on them and let you know how it goes.

[rmbates]

Well, adjusted my settings as suggested and tried again yesterday with the same bad results. Was actually trying to just tack up the pieces as I bent them around the form so I could finish on the bigger machine. Just couldn't get the intersecting 1/8 and 3/16 to pool up at the same time to get a bead started. Did manage to get some crummy looking tacks in place (very dirty and poor form/penetration) and took the pieces over to the Syncrowave. Finished the job in no time with proper welds (only set on 190)....except where I had to weld over the tacks.
Thanks for your help, but I've come to the conclusion that either I have a problem with my TA or gas, or I'm just trying to push that little machine too far. Can Argon go bad in the tank (about 2 years old)?