TIG torch overheating? (Super200P WP17)

[jakeru]

My new CK 200 amp trimline torch is in. I'm pretty excited about it; it basically looks and feels kickass. I also sprung for a special CK "stubby" gas lens setup, (basically adapts a small, #9/#20 gas lens cup onto a larger torch body) which I am also excited to try. The flex head looks like it will be a useful feature.

I have a metric tap set on order, which will hopefully allow me to make the adapter needed to hook this torch up to my Everlast Super200P. I do plan on transferring the torch switch and maybe nylon cable cover off my old torch onto the new one. I like having the torch switch for out of position welding where the footpedal won't reach, or can't be conveniently operated.

By the way, geezer mentioned to pay attention to the torch's duty cycle with AC. This torch has the following rating @ 100% duty cycle: "200 AMP ACHF OR DCSP"

[sschefer]

Good tip by Geezer on the torch ratings. All lot of websites show torches at their DCEN rating only. A Weldcraft 20/250 is only rated at 180 on A/C so if you need to weld 1/4 Al plate you have to jump up to a 350 rated torch.

Don't quote me on this but I think the 18 torch that comes with the 250EX is a 350 torch. I mean, it would make sense anyway and most of the 18's that I've found are rated at 350.

I was over at AirGas the other day and picked up a spare torch. It's a Radnor and I know a lot of you gasp when you hear that name but the guy's at AirGas say they think it's a Linde torch and that's not a bad brand. I'll let you know how it works out, it's just a spare to have in case I burn my good WeldCraft up trying something stupid.

[jakeru]

I'm up and running with the new 200 amp torch. I ended up making a brass adapter to adapt the torch's 5/8"-18 male "inert arc, size B" (also known as CGA-032) fitting to the machine's M16x1.5mm male fitting.

I tried some welding with it, nothing real big yet. I had to butt weld some 1-1/8" wide, 3/8" thick aluminum bar stock for the aluminum sign project. I used the pedal, and only hit the 200 amp level for a few seconds at a time before needing to throttle back. Although I have yet to really test the heat capacity of this torch, I am liking the results so far. (Despite using enough current and A/C balance to melt the tip of a lanthanated 3/32" electrode, the torch handle stayed totally cool, and the slender, flexible portion of the torch connecting the handle to the head stayed cool enough that I could touch it to my cheek!)

The real test will come when I do more welding on the larger pieces of the sign. For kicks, I may try doing it without any pre-heating, just to see how it goes.

I like the flexible head, although I am hesitant to flex it very much for fear of wearing out the flex mechanism. I really like the stubby gas lens setup!

[jakeru]

Update - this new torch works great! I finished the rest of the 3/8" thick aluminum sign project with no pre-heating of any sort, or any stopping to wait for the torch to cool down.

I'd say the new torch has greatly expanded my 3 year old Everlast TIG machine's capabilities. 3/8" even without any pre-heating is all of the sudden, not a problem. There were also no problems from my 3 year old Everlast Super200P TIG machine either, which is now TIG'ing with a much higher duty cycle through the new torch.

[jakeru]

The customer picked up the completed sign project, and he seemed pretty happy with it. I only managed to snap one blurry pic (attached below) but I did give him my e-mail so hopefully he'll share pics of his completed sign with me once he gets his business logo painted in the middle and the sign hung up on his wall.

The quality of the welds really improved with the new torch. Towards the end, and with the new torch, I was learning how to use a bigger gas lens cup and some extra EP cleaning balance % to really clean up the weld bead and make it look all nice and uniformly shiney.

[Adambomb]

That's a pretty cool, unique sign you made. Was that your first aluminum project?

[jakeru]

No, I've done a few others, (if you search the board you will find some of my projects posted up here), especially over the last few months as I've been welding mostly other people's projects.

My own projects tend to be mostly automotive, related to my car racing hobby. I've got an intake manifold I actually started many years ago before I got my TIG welder (with oxy-acetylene aluminum welding), which I will finish up at some point when I have time.

This sign however was my first project of this scale, on aluminum material this thick. Nothing else I've done was nearly as thick as this, 3/8" thick aluminum. The weight of the assembly at the end was just a hair over 45 pounds.

Thanks for the kind words.

[Wrenchtamer]

yeah I hear ya. The reason I was posting the request for the settings is because I have not been able to weld thick sections like that with my machine. I was hoping I could duplicate his settings and give it a go...
you see... I hve always had a problem with tungsten melting when using ac. I have tried and checked everything I can to correct it and finally was able to bump up to a 5/32 tungsten which yielded somewhat satisfactory results... at least it didnt melt right away. I have not been able to figure out any other reason for it except perhaps that I am a poor welder. The machine will run steel and stainless flawlessly. all pulse functios seem to be in order. maybe when the weather warms up a little i cn try to perfect my skills....

Wrench, tell us your settings now...so we can help figure this out. Your 256 should weld it right up...But at 250 amps, you will need definitely a 1/8 or larger tungsten. The normal collet body supplied shouldn't be able to work with 5/32. Are you sure its not 3/32...just trying to figure out, not trying to insult your intelligence

[jakeru]

Wrenchtamer - Does your machine go to 20% DCEP balance on the low end, or just to 30%?

My super200P goes to 20% EP balance, and at that setting, using its full 200 amps, I can not "melt" a 1/8" electrode, no matter how long I hold the arc for. 3/32" electrode is even hard to really melt very much at 20% EP balance, even held at 200 amps. (The above pictured electrode a couple posts up is a 3/32" that may have had some only very minor melting on the very tip, from extended 200 amp usage, just to give you an idea.)

Here is a chart that should point you towards electrode selection. But basically, if your electrode is melting, that is when you would want to maybe consider switching up in diameter (or change the grind to put a wider flat on the tip to let it handle more heat without melting.) There are cases where sometimes a little melting might be OK, and it could be entirely a personal preferance kind of thing. A lot of melting is not OK. You certainly don't want a big blob slumping off to the side, dangling and threatening to drop off into your work. Usually though, on inverter machines like everlast's capable of running low AC balance settings, most folks prefer completely "unmelted" electrode.

The main downside to running a too large of an electrode I would think, is that it might be hard to get the arc started or control the arc very well at low amps. You might find the arc hard to start (exiting the high frequency "buzzing" mode and switching into normal welding current mode), and I imagine you might also see the arc kind of randomly "dance around" if you are not putting enough current for the electrode.

I generally have found the CK Worldwide electrode and shielding gas selection chart to be pretty helpful for starting point on electrode size selection, as well as shielding gas flow rate selection. (Keep in mind cfh's given int is not equal to lpm found on everlast flowmeters.)
http://www.ckworldwide.com/tech-3.pdf

Are you using a water cooled torch without coolant at very high amps? If so, I wonder if your shielding gas hose is melting on thick aluminum, and contaminating your welds and your electrode. You might find somewhat of a workaround to use higher AC balance than the minimum allowed by your machine to clean up the contamination, but that will cause more melting of the the electrode. Can you post more pictures or details of your machine and setup?

[Wrenchtamer]

my machine is a pp256. It goes from 10% to 90% ep. it looks like all the other 256s out there. when I get a few minutes I will try to strike an arc with a 1/16 or 3/32 and show you the result. I have a different reguator on my bottle... Dont remember what kind but I got it from praxair as well as all my electrodes. I have 1/16, 3/32, 1/8, and 5/32. all are 2% thorium except I also have some 2% ceriated in the 1/8. standard torch. I would persue the suspicion that my torch was malfunctioning but for how well it performs in dc. It is a water cooled torch, though. I have a makeshift cooler that I slapped together from a pressure vessel I made from the bottom 1/3 of a fifty gallon barrel. It is airtight so I just put my coolant in there and I have an air fitting with a regulator so I just dial in the pressure without the need for an expensive pump. Works great, the torch head doesnt overheat. If I use the 5/32 electorde it doesnt melt, but yes I do get some arc wander. I'm not unsatisfied, I would just like to learn how to take advantage of this unit's purported capabiities. will try to get soe more images in soon. btw, can I use my labscope to monitor the a/c frecuency and balance? I dont know enough about wlders to know how. i could use a fused input but I think te hf might still fry it.

[sschefer]

Here's a couple of things I've found to lessen the spitting tungsten syndrome with A/C:

1. Don't grind your tungsten to a point, leave a blunt end.
2. Square the end of the tungsten before you grind the bevel.
3. Hold the tungsten against the grinding wheel so the wheel is moving away, (from the shaft to the point).
4. Polish the grind with a scotch brite wheel and clean with acetone.
5. Use no more than 35% DCEN. Start with a balanced 50% and work back from that.
6. Make sure your foot pedal is not skipping on you. If you reach inside with your finger, you can push the rack back and roll the pot back (up) to it's starting point. Do this frequently or consider a aftermarket pedal.
7. Make sure your gas is clean and your gauges are working properly. Get a torch gas flow gauge or a torch with a gas valve to help fine tune the flow.
8. Use a gas lens or make sure your cup size correct, (IE. 3/32 electrode - #6 cup).
9. Use the least amount of stickout possible. 1/8" is a good starting point with 12-15 cfh of gas. Increase to around 25 cfh when welding a fillet weld with more stickout.

Just some ideas that seem to work for me.

[performance]

Our units are listed as percent of positive electrode...not negative. That is a frequent issue with people that do not understand how our units are set up. I had a recent opportunity to talk with Miller design engineers at the Fabtech show. And I brought up the issue of how they rated the units. I asked them since we refer to cleaning action and not penetration, how come Miller refers to percent negative...

They kind of whinced and nodded their head. They looked at each other and one of them told me, that it was an old design engineer years ago that actually got it set up wrong, and they knew it was wrong, but since it was the "traditional" way that they did it, it was sort of ingrained in the Miller culture and they had to do it out of the force of tradition.

So, set it at 30-35% of positive electrode, not negative. There's a big difference. If people set it at the traditional 60% to 70% according to Millers way, then there are going to be significant issues with arc wander and tungsten balling.

[jakeru]

I haven't done any such scope measuring on mine, because I don't own a scope, and I also don't have reason to suspect it not performing well.

Anyhow, I can't tell what your knob positions are from that pic, or what your tungsten stickout, etc looks like. This is what I hoped might be apparent from the pics. Although good info on the machine and torch. So, how about some pics that show your knob settings for a typical "electrode melting" setup of yours, and another one that shows your tungsten preparation? I'm sure if you shared enough details, there are folks on here itching to help you figure this out. You are welcome to use this thread to figure this out, if you wish.

Also is the whole electrode melting forming a huge melted ball, or is it just the very tip of it that is melting? If its just the very tip forming a small melted ball on the end, try grinding a larger flat on the tip. This will help increase the amount of current the electrode can take while remaining stable, and not melting.

What I would try is run the very minimum cleaning balance %... so balance knob turned all the way counter-clockwise, at 10% EP. That should take as much heat off the electrode as possible, while still operating in AC mode. Try that and see if it helps take the heat off your electrode. Also, I would hold a "tight arc". I know a long arc makes the machine work harder, and output more volts and more power. I'm not sure if it has an affect on more heat on the electrode, but perhaps it does if excessive. You want to hold your tungsten just about as close to the work/puddle as as you can while not touching it.

[jakeru]

By the way, Steve - I just tweaked my footpedal some more, so now I've got a wider working range, of about 1 amp - 197 amps. Previously, it was kicking in at much higher than 1 amp, and it was also not getting nearly as close to the full 200. I'm stoked about it!

[Wrenchtamer]

ok so here are some photos. I tried to upload a bunch more but had some trouble with it, so here are just a few. basically i ran three (six) test beads at three amperages both all the way down and all the way up on the balance. 35 amps, 50, and 70 I think. by the time i ran the first 70 amp bead the tungsten was unusable. all of these beads were around 7 seconds. i dont have a lot of time for this post but i will fill in the blanks soon. sorry about that. and no i wasnt welding with that much stickout, I just pulled it out for visibility. The left and right columns are at 10% and 90% respectively. from top down, its 35, 50, and 70. I have used ceriated, thoriated, and lanthanated electrodes from three different sources too so I kind of ruled that out. this is my second tank of gas too so I dont think it's the gas. I don't know... If any of those eager to chime in have any questions let me know. I'm sure I left out some important info.

[cmd]

ok so here are some photos. I tried to upload a bunch more but had some trouble with it, so here are just a few. basically i ran three (six) test beads at three amperages both all the way down and all the way up on the balance. 35 amps, 50, and 70 I think. by the time i ran the first 70 amp bead the tungsten was unusable. all of these beads were around 7 seconds. i dont have a lot of time for this post but i will fill in the blanks soon. sorry about that.

Maybe someone will know but I use thoriated and have used ceriated in my 250ex and I've never seen it melt the tungsten, so I really wonder about your tungsten. I use 3/32 for almost everything. I can get the end to look really nasty but nothing like that, not like its going to drip off. i guess its got to be in the balance if its only in a/c tho?

[performance]

THAT looks like aluminum hanging in a blob. The blue is an indicator of poor shielding or gas contamination.

[Wrenchtamer]

that isnt aluminum. It's tungsten. Normally I know the blue would be considered a virtue of inadequate shielding, and indeed it may be but I hink it only oxidized like that because it melted. I am 100 % sure that at no time did I touch that electrode to the work. I am just trying to figure out what the problem could be so i can correct it. I know you want to assume it's operator error, and I'm not ruling that out but I can rule out aluminum contact and pretty much gas. It only does this in ac mode. Have you ever seen one of your machines behave this way?

[everlastsupport]

Wrenchtamer,

Take a clean stainless steel brush and polish up a spot, wipe it down, cut the tungsten and taper it a little (the end will ball by itself, set the balance to the 10 o'clock position and try it again. That should give you a good start point if the unit is working right. The rest on the panel looks good. You are running straight argon? The etching looks like a balance issue.

Try 70 amps (low, but looking to see if it is the welder or not) and no foot pedal. Use a thoriated electrode? Gas at 8L or 12CF, your stick out looks OK from the picture. No filler, just try to make and push the pool and shoot a picture.

[Wrenchtamer]

yeah that's straight argon. for 3/32 I only have 2% thoriated. I can go to 1/8 I have some 2% ceriated. I will try it and take some pics. 90 amps is going to burn it real fast tho.