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-
I have the paper manual, but I will download the manual also to see if there is any difference.

I have been using sand paper/grind wheel and acetone but I am always looking into better options! Speaking of grinding wheel I am using a bench grinder for my tungsten that has been used on just about everything in my shop.....I grind the tungsten so the tip stays fresh (wheel moves away from tip) but do you think that is sufficient even with lower grade tungstens? I am currently using "ForTune" brand tungsten and HTP america filler rod (came with the welder from the guy I bought it from)............just as an FYI. Yes I looked more closely at your regulator and it is reading about 6 LPM, I have tried up towards 15 and down to 5.....all produce a very similar bead, my problem might be that my base material isnt quite clean enough.......

[Tritium]

The paper manual in a word isn't.

Thurmond

[chevyracer56]

Tritium- Wow....there surely have been some improvements between those two "manuals"! Yea the paper one didnt really tell me much, although the one online isnt perfect its amazing by comparison

[chevyracer56]

So I decided to make a few passes on aluminum and only changing the AC balance, far left weld with with the balance fully counter clockwise and as the welds progress to the right so did the ac balance being turned completely clock wise. To me it seemed like with the balance all the way clockwise the arc has a harder time stabilizing but welds better once ti does stabilize?.....I still dont really see any of the "cleaning" on the outsides of my welds though.........again regular sheet aluminum, 3/32 red band tungsten, ~6 LPM argon, 4043 filler etc.

Also I tried to do some more butt welds and varying the frequency......it seems like I am having a hard time bringing the two puddles together but once they come together it welds just fine....any tips? (same thing with a lap joint I tried with the same settings...........oh and neglect the burn through at the end , my downslope decided sometimes it wanted to work and other times not :-P

[DaveO]

Speaking of grinding wheel I am using a bench grinder for my tungsten that has been used on just about everything in my shop

I'm out of my depth here, but there's been a number of posts that say to use a dedicated grinder for tungsten to prevent contamination. Could this be why Chevy's welds are not turning out as shiny as he expects?

[performance]

You are getting cleaning. That white area is "cleaned. But it looks like you are starting your arc in one place then dragging it to another to weld.

[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.

[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]

So I made my own "special" tungsten grinder.........I put the tungsten in my drill press and then held a die grinder with a new pad on it and a angle (with it rotating to pull the ground material away from the tip)......when I was done the point was nice and sharp and actually polished looking. I tried a few welds (thick and thin steel) but the looks remained constant. Is there any particular way to test the gas?

Also I noticed my 2.4 mm collet thing recently became deformed (twisted)(due to heat??).....any chance that might be preventing gas flow?

[performance]

Try 70S 6 wire, more oxidizers=cleaner welds.
I just wrote a nice little guide for you, but a power fluctuation hit and lost it.

I'lll hit the high spots again of what I BELIEVE to be the problem. Likely you have a couple of issues compounding the problem.

You are moving slowly from the appearance of your welds, and likely overheating them (the twisted collet is definitely a sign) by welding at too high an amperage. What is resulting is you are putting a lot of heat into the metal, and the weld is cooling slowly after the argon is gone. Likely its still a red or dull red color after the torch has passed by and the gas has dissipated. This will cause rapid oxidation at the weld surface, since the metal is cooling in the presence of oxygen. Torch angle and gas flow can be a cause as well...but I think from the look of the weld you are putting too much heat into it and moving too slowly. Work your torch side to side to fuse the weld, just carry enough heat with you to keep the immediate area melted. If you have a big puddle trailing behind you, it is too hot.

You won't remove much mill scale with a scotch bright very easily. Don't be sissy with it. Grind it.

[performance]

The way you are doing your tungsten does have an issue, by transversely grinding the tungsten from the rotating pad you are creating spots for the arc to jump around. What you are using will contaminate the tungsten as well.

[chevyracer56]

Peformance- I think I get what you are saying, which means I have always ground my tungsten's wrong....I guess with aluminum the problem is more apparent (I had only done steel before). So to make sure I have this right the grinding should remove material parallel/longitudinally, correct? I will try this and report back.

I though the same thing as you about the speeds, so I tried slow speed low heat, fast speed high heat, medium heat medium speed, and they all produced the same result. by the end of the weld the end of what I am doing is glowing red but I have the post flow on until it stops glowing. I do recall having this same exact problem when I first started TIG'ing, but after a change of the bottle ( a week later) it seemed to go away...not sure if it was due to experience or gas though.

The overheated collet likely happened when I was playing around with the 1.5" solid axle that I showed previously (welding on 200 amps). I will play around with torch angle some more as that could also be an issue. Although I am a little perplexed on how I can overheat the material (relatively speaking) when I am only keeping the hear on long enough to have sufficient penetration and then moving on.........I suppose I could try laying a bead with almost no penetration to find out if this is the issue though, correct?

Thanks for your help

[chevyracer56]

So I tried a few different things......I ground my tungsten long ways......I used a bench grinder and place it again so that it removes material parallel but instead of rotating the tungsten I ground it, lifted it up, turn it some, ground some, repeated until I got all the way around............if I understand that is the "correct" way to do it?

Anyhow I didnt try aluminum but things on steel seemed about the same, I tried large/small/no torch angle (relative to travel) and it made no different (although at perpendicular I did get some porosity), I also tried high amp/low amp, good penetration and a very superficial bead......all still produced the same grey weld..........I under decided to grind the work piece front and back to prevent contaminants from being pulled through....but no luck there either.