Powertig 200DX fairly new TIG welder

[chevyracer56]

Hey everyone, I am not new to welding but I have only been TIG welding for about 6 months now (off and on).......I cut my teeth on a dynasty 200 dx building a F.S.A.E. chassis for my senior design, so I am a little spoiled I suppose lol. I also got to play with a few other machines but the dynasty was awesome and never missed a beat while being extremely consistent. Anyhow since I am a college student and I race circle track I dont have much spare funds (but always looking for sponsors!) so I decided to buy a everlast welder. I was able to pick up a 2nd hand but brand new powertig 200dx with foot pedal, tig/stick torch, 8 lb's for filler rod (steel and aluminum), 4 packs of tungsten and some gloves for $800.....so I couldnt pass it up

Anyhow I got home and wired up my 220, went to my local airgas and got a big argon tank (traded one of my 75/25 tanks for it) and started welding. My foot pedal didnt really work right but thats in the process of getting fixed, so I have been using the switch on the torch and I am slowly learning to like it although I wish the torch itself were alot smaller!

Currently I am very happy with the machine, it seems to be doing what it is supposed to.......although I think I am a little rusty and not a professional by any means. Currently I am trying figure out why my steel TIG welds arent coming out as "shiny" as I am used to on the chromoly chassis I did and why I occasionally seem to get a little porosity. I am also still trying to figure out aluminum as yesterday was my first time ever attempting it.....some of my welds come out decent for a newb but some of the time the machine just stops welding (like it no longer has an established arc) and I have to press the button again, perhaps this issue will fade with having a pedal though.

Well onto a few pictures,I am always looking for advice and hope to get this machine dialed in so that it'll produce a consistent/nice/structural bead. Everything was welded DCEN and torch control with a little pre flow and a good bit of post flow.

First attempts on mild steel scrap, red band tungsten

First ever attempts at aluminum, pure tungsten (green band)

1/8" steel plate, between 70-120 amps and 5-15 LPM on the EL flow meter

red band tungsten

[chevyracer56]

I decided to try a few different setting and tungsten on aluminum. 3/32 2% thoriated (red band) tungsten, 4043 filler rod, .040 sheet aluminum, 30 amps, no pulse and it seemed to work a lot better.........using the pure tungsten it would form the ball at the end and the arc would want to wander a lot. Although I am still struggling to have the filler rod not melt before depositing right after I start (you can see it on the 2 left welds).

Also why is it that most of the other welds I see seem to have more of the frosting (etching/cleaning whatever its called?) on the outside? and is it needed?

[sportbike]

Turn the AC Balance knob (one of the yellow knobs) counterclockwise. The cleaning will help you wald a bit better and may help with the starts. The green tungsten really isn't needed, the red, thoriated will work for everything you will be welding.

[chevyracer56]

Sportbike- Thanks for the response, so I should turn the balance more towards the -30% side right? I will try that later today or tomorrow, but if I recall right from experimenting it made the arc "walk" alot more until the puddle formed, is that normal?

yea the red thoriated seems to be doing a good job, I have been interested in trying 2% lanthanated (blue) or the ceriated? (orange) band.

Also I tried to put a couple of pieces together instead of just welding on sheet and it was tough....is it beneficial to lower the frequency (to widen the arc) so that you can melt both sides at the same time or do you have to just dip one side at a time and join them?

[chevyracer56]

I got bored and I decided to crank up the DC amps...machine said 206....anyhow I just wanted to lay a bead on a spare 1.5" axle I had.......I must say the machine lit up nice and held a very stable/smooth arc .....I think that is a er70-s2 1/8" filler rod btw

Also if you look at the welds it shows what pretty much all of my welds look like on steel so far....they are all "grey" in the center.......I am used to seeing a much more shiny weld with chromoly....is chromoly just special like that or is something else causing my welds to appear this way?

[performance]

Have you downloaded your manual?
If you start welding on mill scale, you will not have a shiny weld. If it is dirty or contaminated it won't either. Gas flow is usually an issue as well. What is the flow rate? Our regulators are in liters per minute, not cfh.

[chevyracer56]

Performance- responding to your questions in order, but yes the torch is hooked up to the negative terminal on the welder.

1. I have tried grounding at the work piece, on my table, on both etc. and honestly have not seen any difference.
2.The clamp it self does not get hot, although I noticed that the bolt opposite the actual grounding wire seems to get a bit toasty, but the rest of the clamp feels normal.
3. I do suspect that perhaps my tungsten, via my grinder, is a issue......I suppose a new grinding wheel would easily fix that problem though?
4. Very possible, mistakes do happen......at the rate I am going I will be through this entire bottle in another week or two lol
5. I generally try to start as close as possible, saying 1/8" was on the upper limits although while I am traveling with the torch I probably do sometimes get "gaps" that large occasionally....I have also tried resting the ceramic on the work piece with starting but did not seem to benefit from that (in an effort to getting a closer start)

I am going to include some pictures I just did on steel....I used a scoth brite twist loc and cleaned the metal pretty good, did a weld (80 amps, 1/8" mild steel), aceton'ed, did another weld (90 amps)...both look about the same in regards to being shiny (or lack thereof).

[chevyracer56]

performance- That works....I have just seen that "frosting" around the entire weld on some peoples...again I dont even know if it that is preferred or not, just comparing. I am holding the torch in the same spot but when I press the button the arc "hunts" around for a little bit then once a puddle starts to form you can hear it change (sounds like a change in frequency) and once that happens its stable.........but until then depending on the balance (it seems) the arc will initially wall all over the place.......and the larger my arc length the more it will walk, but those pictures with with the tungsten probably less than 1/8" off the metal.

[performance]

Chevy,
A wandering arc is usually a result of one of about three, four, or possibly five things. ( You do have your torch in negative right?)
1) poor placement of the work clamp, not directly to the metal itself, having to route the electricity through the table etc.
2) Corrosion on the work clamp. Check to see how hot the clamp is. IF it is hot, you need to move it, or disassemble the cable and the clamp and clean all connections.
3) Contaminated tungsten, is actually one of the most common causes. Learning to tig is always a grind, regrind, regrind some more process.
4) Contaminated gas. Sometimes welding supplies get lazy and don't properly vacuum the tank before they fill it. Or they accidentally mislabel it.
5) Holding the tungsten greater than about 3/32 off the metal will cause a lazy start.

[Tritium]

Chevy,
A wandering arc is usually a result of one of about three, four, or possibly five things. ( You do have your torch in negative right?)
1) poor placement of the work clamp, not directly to the metal itself, having to route the electricity through the table etc.
2) Corrosion on the work clamp. Check to see how hot the clamp is. IF it is hot, you need to move it, or disassemble the cable and the clamp and clean all connections.
3) Contaminated tungsten, is actually one of the most common causes. Learning to tig is always a grind, regrind, regrind some more process.
4) Contaminated gas. Sometimes welding supplies get lazy and don't properly vacuum the tank before they fill it. Or they accidentally mislabel it.
5) Holding the tungsten greater than about 3/32 off the metal will cause a lazy start.

And 6) trying to weld in a breeze (in front of the welders fan in my case). The arc was all over the place.

Thurmond

[chevyracer56]

performance- perhaps you are right and my mind is playing tricks on me.....perhaps the reasons I saw so many "shiny" welds when I did a 4130 chromoly chassis is because anywhere near the tube ends were polished before welding and once welded they had a colorful HAZ, perhaps all of that combined is why I recall the welds being shiny when in reality its just everything else made it seem that way?

On another note, I have been using er70-s6 rod, I used a little spare S2 rod i had laying around of known quality (the s6 I have came as part of the package with my welder). I will try beveling some thicker pieces later on and see what it does

Lastly I tried some more aluminum and the arc. is definitely more stable at the start than it used to be. I also realized why I might be having trouble with my filler occasionally.....it is 1/16", and even though I am only welding on 30-40 amps perhaps that is too much amperage for that tiny filler, I will source out some 3/32 perhaps.