TIG torch overheating? (Super200P WP17)

[jakeru]

I was welding some 3/8" aluminum, at minimum (20% EP) balance with max (200 amp) current my Everlast Super200P could deliver, with no pulse. The aluminum was cleaned pretty well - sanded, brake parts cleaner'ed repeatedly until the rag came back clean. I even scotch brite and solvent cleaned the filler rod.

I could manage about 2.5" of shiney clean weld bead, and then it would start welding nasty - oxidized, contaminated, etc. A little bit gradually at first, (just a little "pepper in the puddle",) but then the oxide skin would grow worse until it would get to thick it would prevent the puddle from wetting out.

I tried a bunch of things to fix it - changing the tungsten, changing the collet, changing the cup, checking the gas flow. The problem always kept coming back as I welded. My tank of argon was running low, about 400 psi left (which is about 20% of new fill pressure for me) so I did one last test to see if it was bad gas at the bottom of the tank. I hung things up and let it all cool off, and then came back the next day to try again. I again got a few inches of shiny weld bead and then the contamination would come back as the torch and cable heated up.

When the torch was hot, I was still able to hold it by the handle (but not up close though.) I also noticed a distinct smell which is hard to describe, but maybe was melting plastic. It seemed like the argon gas coming out of the cup has this smell. And I noticed that the power cable, draped over my shoulder, was getting noticeably hot too, especially the portion up close to the torch. (The portion of the cable back by the machine wasn't hot.)

So my end diagnosis was, running the torch/cable too hot somehow caused contaminants to be introduced into the shielding gas. Does this sound like I got it right?

I tried tightening the connector inside the handle where the power cable connects to the torch, but it didn't cure the problem. Is the torch I have (says "WP17" on the side) just inadequate for this 200 Amp machine?

[geezer]

Yep, you have reached the limit of a WP17 torch, Weldcraft rates their wp17 at 150 amps, you are using 200 amps without pulse, that's gotta heat things up, time for a water cooled torch.

[sschefer]

Jakeru, had a problem like that with 1/4" a while back. It was stuff that had been hanging around for a while. I ended up throwing it in the oven at 400 degrees for an hour and then re-cleaning it. That's a trick I use on cast outboard motor blocks and it worked here also.

Your torch reached it's limit at about 150amps like was said by geezer. Looks like it's time for a water cooled. Check out Weld Craft's torches they have a little better cooling design than the WeldTec's. I have both a WeldCraft and WeldTec 20-250 torch. The WeldTec still gets warm at the higher amps but not severe like my air cooled 17. The WeldCraft stays pretty cool. I have the WeldTec cooler. I'm not sure if there's a difference in them. Mine seems to work well.

[everlastsupport]

Jakeru,

I normally tell people 140amps (keep them from burning it up), but Geezer is right, it is 150 or 160 on the spec.

You might want to call into the office and get a price on a water cooled torch. It's not hard to make a cooler if you're on a budget, or you can run city water through it for occasional jobs. Some guys only use the tap actually.

[jakeru]

Thanks Mike. I think I've actually been struggling with overheating this torch since I got the machine, but only recently just figured it out. I just never made the connection that overheated torch = contaminated welds and tungsten. I just thought the torch would just get too hot to hold, or perhaps somehow visibly externally "melted".

I would like to upgrade the torch to allow fully using the machine's 200 amp capabilities. Do you guys sell or have you sold a 200 amp air cooled torch option?

[trackmaster]

Hello gents, hey just wanted to jump back a few posts to wrenchtamers question about Jakeru's settings. Great post of info by jakeru there, but Tamer, i just wanted to make a comment, .... from an old timer Tigger, ya know back in the day we didnt have Inverters, Balance adjustment, Nor Freq.
The point i'm tryin to make is that those features are great tweaks to allow you to really dial in your process, but the basic process itself does really just fine at it's most basic. What i mean to say is that 5 different welders will get a job done in at least 3 different ways! So someones settings are great if you have the EXACT material, age (corrosion, cleanliness, etc). I would by far encourage someone to really understand the process and features, and oh yes, ...... the technique to really become a great welder. Not saying that a good starting point isnt way helpful, just that it's really easy for a newer welder to get a little to wound up about some of the features and capabilities of the newer technology and search for success therein.

I'm a pedal guy so amperage for me is set enough or then some on the machine, ( no biggy cause your gonna regulate it with the pedal anyway) , balance, well most of the "older" machines that could lay down AMAZING welds, were fixed anyway so rather think about what it does. Really in practice, 2 things, if your metal is kinda dirty old and ratty or castings, it offers additional cleaning. Start at your most electrode negative setting and little by little dial in some positive till you see desired results, ... of course with the upper limit of EP being starting to erode or melt your tungsten. The other thing you might use to advantage with the balance control is varying or tweaking penetration and bead width. The more electrode negative the more penetration, but narrower bead profile, and visa versa. The take home point is that on most garden variety welding, if your within acceptable limits on any of these you still will be able to make nice welds. the exact settings dont really matter except for when you really get a hold of your technique and want to dial in the welds. Thats when these machines get really fun!

Frequency is really in the same boat. where ever you have it set (whithin practical limits) is still going to yield good welds if your prep, and technique are up to speed. So thats all I'd like to add. Its really a game of basics, till ya get rockin, ..... then worry bout all the toys! Clean and prep the parts and make your fit ups well. Just like the guys are sayin tho, thick aluminum is going to give a newer aluminum welder fits unless its good and hot (pre-heated). I use an old grill, and put parts right in there to preheat. hope ya don't mind a few cents worth of 30 some years at it. Rock on!

[performance]

Trackmaster,

I fully understand your sentiments. Great shoes didn't make Michael Jordan a better basketball player. He could have played great in pumas from walmart. He had the fundamental basics to do anything he wanted with a little orange ball and a woven net hung on a round metal rim.

One thing I have found though, that should be considered, is that these settings, if the right spot is found, makes tig welding a little easier and learning to lay a good weld much faster. The 60 hz and 50/50 balance of the older welders sometimes offers a unique challenge when welding aluminum by keeping the ball just right and the arc stable. With the inverter settings that can be achieved, improved arc stability is gained and new students can learn basic technique without having to battle things that become second nature after years of practice, that you may no longer remember were a challenge.

The challenge is to inform the new welding student/customer about the impact each function has on the weld and how to find the optimum settings which will be best for their situation.

So, one thing we have done is to introduce the new PowerTig 185 Micro for those guys who prefer more basic performing tigs so that they are not distracted by a lot of extra controls and functions. It does have frequency and balance control on the AC, but no pulse no fancy settings or startings or even other processes. Just plain and simple TIG...with the slightest bit of frills to keep things interesting.

[sschefer]

Trackmaster, great post. Mark, that's cool that Everlast took the time to look at it from a different perspective and give welders an option.

[geezer]

Just so you should know, torches have different ratings for AC & DC, a typical WP 18 water cooled torch is rated @ 350 amps DC & 250 amps AC, the reason AC is lower, cause the electron flow is towards the torch from the base metal on the AC cycle, on DC the flow is towards the base metal.

[jakeru]

Mike, it was nice chatting with you on the phone today. I am always impressed when I call a company, and someone just picks the phone right up like you did.

I have a feeling my Super200P's "coaxial" WP-17 torch argon/power cable (rubber hose with some type of conductor inside) overheating was what was causing the contaminants introduced into the shielding gas.

I wanted to post a picture of one of the decent welding beads I managed, connecting a sawed in half aluminum road wheel to a 3/8" aluminum plate, which I managed with the ~150 amp rated WP-17. I had to do this about 2"-2.5" at a time, then set the torch down and keep the post-flow running for a minute or two to cool it. Before the next bead, I'd then pre-heat the work with a good 10-15 second blast from a high-BTU propane "weed burner", which made it easier to get the next 2-2.5" weld bead started. Rinse and repeat.

I got the job done, although some of the welds weren't the best before I figured out the contaminated gas from overheating argon/power cable thing. :eek: The project is just a sign however, and luckily the customer was going for the "industrial look" and was completely happy with my welds, so its all good. Just took me a while (A LONG WHILE!) to get this done with the WP-17 holding me back.

I am liking your suggestion of a water cooled torch upgrade. I think that's great that I could use a water cooled torch without water, at lower current levels for convenience, just like an aircooled torch. Sometimes I really appreciate keeping my setup portable so good to know I wouldn't need to lug around a cooler or need city tap water wherever I took it. I like to sometimes just throw my argon bottle, welding machine, and the couple necessary cables (torch/ground), into the back of my car, plus my little welding toolbox (with little clamps, some filler rod, safety gear, etc) into the back seat of my car, and be ready to weld wherever there is a 240V 30A clothes dryer outlet. I look forward to connecting with Everlast sales about a torch upgrade after they return from fabtech.

My customer says he has some additional 3/8" aluminum pieces planned (in addition to a few ~1" or so cubes!) he still is going to want me to weld onto this custom sign I am helping him make. :o

[Wrenchtamer]

hey could you post the settings yu were using when you welded that wheel up? balance, frequency, tungsten type and size, amperage and flow rates? One of the first jobs I attempte on ac after I got my 256 was welding on a wheel like that and I could never get it right...

[jakeru]

200 amps (max of my Super200P), 20% EP AC Balance (min of Super200P) 60 Hz AC frequency (nonadjustable on Super200P), no pulse. Used on/off torch switch (no footpedal on this.) A TIG finger was useful on this, as was walking the cup. And of course, crank the post-flow up to the max (and keep tapping the switch to keep it flowing, to help cool the torch.)

1/8" 1.5% lanthanted tungsten, sharpened tip with a flat on the end, switched between gas lens and standard collet bodies (whatever was coolest... kind of preferred the gas lens), #5 and #6 cups both worked fine, about 10-15 cfh or so argon flow. 100% argon gas. 3/32" 4043 filler. (Liked this better than my 1/8" 5356, probably because of 4043's slightly lower melting temp.)

Maintained torch temps by taking breaks (leaving the gas flowing through the torch most of the time) every 2"-2.5", and pre-heating the part for 10-15 secs with a 281k BTU propane weed burner before the next weld.

Gotta really watch the torch angle on this to keep the end of the filler from going molten by the way!

Here is an overall picture of the sign. I am not proud of some of the welds on this however, before I developed the torch overheating prevention techniques, necessary to keep clean shielding gas.

Tack welding without any pre-heating worked just fine. Just hold the torch still for however long it takes (7, 10 seconds?) for both parts to melt, and bridge the gap with some filler. 1/8" 5356 made for for nice and strong tacks on whatever material this was (I have a feeling the bar and plates were 6061.)

[sschefer]

Jakeru, just curious. Is this the only welding process you have? The reason I ask is that I use a Miller 212 and a 3035 Spool Gun when I have that much welding to do on thicker Al.

Please don't mis-understand me. TIG is always going to look better and produce a stronger weld but with MIG, you'd have been done in an hour or less.

[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.