High amperage TIG with a WP-20 torch

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I've been doing a lot of aluminum welding lately, using a transformer based machine, and using amperage over 250. I'm using 1/8" tungstens, and have tried both 2% thoriated and Pure. I've settled on the pure as they don't split like the thoriated do, and trying to maintain a pointed tungsten on AC at these amps on a transformer machine is hopeless.... Anyhow after about 270 the tungsten gets angry, and tends to shake and build too big a ball on the end. I think what I really need is a bigger tungsten, but how could I make that work on a number 20 torch when 1/8" consumables seem to be the biggest available?Depending on where I'm working I can sometimes use a Miller Dynasty 300DX and can get 300 amps AC through a 1/8" ceriated tungsten with no problems at all.... But the transformer machine, that's the problem.....Proud to support Reliable Sheet Metal Works, in Fullerton, CA.Full service sheet metal fabrication serving Orange County since 1926.http://www.reliablesheetmetal.com
Reply:Well the simple answer is that you need a bigger torch. You are going to blow it up.Miller Dynasty 700Miller Dynasty 200Miller 350pMiller 252Hobart Handler 187Lincoln Weld pack 180Victor O/AHypertherm 1250Hobart Airforce 500IPractical cnc
Reply:Look to ceriated tungsten maybe. Not 100% sure which tungsten was gold colored, but that stuff dealt with high amps with little issue. For me, I just live with the Thoriated cracking, as the pure balls up really badly and sometimes would blow off. Make about 10 tungstens to start, and then burn them up 'till you are done or it's time for lunch. Grind them back clean, and get back under the hood.And then, after so much work...... you have it in your hand, and you look over to your side...... and the runner has run off. Leaving you holding the prize, wondering when the runner will return.
Reply:I think that zirconiated are rated to handle the higest loads.Miller Syncrowave 350Millermatic 252/ 30A spoolgunMiller Bobcat 225g w/ 3545 spoolgunLincoln PowerArc4000Lincoln 175 Mig  Lincoln 135 Mig Everlast 250EX TigCentury ac/dc 230 amp stickVictor O/AHypertherm 1000 plasma
Reply:You problem are running a higher ac balance on the newer machine... I wonder if the sine machines generate more heat in general as well?HTP Invertig 201Lincoln Idealarc SP250Miller 180 AC StickBy farmall:They should have held the seagull closer to the work, squeezing evenly for best deposition.
Reply:Thanks for the comments, it's at work, and I hate asking the boss for something we don't really "need." If it were at home I'd fork out for a new torch, like the weldcraft WP-18, which is rated for 350 amps continuous, and will hold a 3/16" electrode that's because I'm a tool junky. But it's different when you're trying to make money. A split 1/8" thoriated electrode actually welds pretty well, and you can still do the job at 250 amps if you go a little slower.... The job I'm doing at work only has 3 inch welds, so even at 300 amps AC, the 20 size torch head seems to be okay, just wish I could shove a 3/16" electrode in that thing....Proud to support Reliable Sheet Metal Works, in Fullerton, CA.Full service sheet metal fabrication serving Orange County since 1926.http://www.reliablesheetmetal.com
Reply:I use a WP-20 all day every day with the machine set on "Kill"300+ amps with aluminum not a problem..And all I ever use is 3/32" Red end..There is another discussion here about torches and their limits..http://weldingweb.com/vbb/showthread.php?t=62618...zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:The other guys all use 3/32 red tungstens too, even with the machine set at 280, I've never seen them able to push that much through that tungsten as I can see the panel amp readouts while they are welding. Maybe they could and won't, all I've noticed is they generally don't. Now on the inverter machine, I can totally rock 300 amps AC through a 1/8" ceriated tungsten and keep the point too, but not so on the transformer machine.... It just seems to me that there is too much resistance at those amps and proper AC ballance on the transformer with that small tungsten. If you think of the tungsten as a sort of electric hose, you can push more electricity through a bigger hose...... are you doing AC on a transformer machine Zapster? Thanks for the input.Proud to support Reliable Sheet Metal Works, in Fullerton, CA.Full service sheet metal fabrication serving Orange County since 1926.http://www.reliablesheetmetal.com
Reply:Insterno,As mentioned the zirconiated tungsten will handle the heat better than pure and will give you a more consistent ball (not the many small balls of thoriated).You don't mention the machine you're using.  There is a difference in the newer squarewave machines and the older sine wave machines (Zap uses a sine wave machine-330 A B/P I think).  With the squarewave machines you have a balance control.  The higher you set your balance (DC-) the more heat you put into the workpiece vs the tungsten.  The inverters take it one step further, enabling you to adjust the frequency upwards of 60 HZ.  This focuses the arc and results in more penetration.Weldtec makes a HD 20 series torch that will take a 5/64" tungsten and is rated at 310A.  They also make the Speedway series torches.  The 20 series will also take a 5/64" tungsten and is rated at 320A.  This is the torch I use on my Sync 250.I've had better luck with the 2% Lanthanated tungsten (for AC welding alum) than I have with the Thoriated.  Still forms a ball but doesn't split and form the small ba11s as bad as the Thoriated.  I don't do much tig welding at 300A though.  Most of my alum tig is around 200A or lower.Using the tools you already have, I'd recommend trying the 1/8" Zirconiated and 1/8" 2% Lanthanated tungstens.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:I thought that transformers on AC required balled tungsten and inverters required a pointed tip?   I could be totally wrong though.   would explain why he has problems keeping a pointed tungsten on a transformner...Tiger Sales:  AHP Distributor    www.tigersalesco.comAHP200x; AHP 160ST; MM350P,  Spoolmatic 30A; Everlast PowerTig 185; Thermal Dynamics 60i plasma.  For Sale:  Cobra Mig 250 w/ Push-pull gun.  Lincoln Wirematic 250
Reply:I guess that's why some posters "post an awful lot" and quite often don't have a clue what they're talking about.Never "been there and done that" but they "read about it on the internet".Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:I have some Zirconiated tungstens, but only 3/32, they certainly carry more load than pure, but if a 1/8 pure isn't close to doing the job, a 1/8 zirconiated probably will be better but not quite good enough. Plus a box of 1/8 zirconiated tungstens costs over seventy bucks. The machine is a fairly new Lincoln Precision TIG 275. I've just purchased some CK reverse 1/8" collets that I think can be drilled out to 5/32 and accept standard TIG nozzles, and a box of 5/32 new old stock Zirconiated tungstens. I think I'll be able to rock the 5/32 Zirconiated tungsten setup with these, I'll let you guys know.By the way, I know I'm being a little stupid here, and could probably do the job just fine just like everybody else with a funky split 3/32 thoriated tungsten, but I'm just one of those guys who says there's got to be a better way than this!Wish I could just use the Miller 300DX Dynasty all the time, that thing is one sick slick Aluminum welding machine!I'll let you all know how the 5/32 Zirconiated tungsten setup works out, whether it's really any better, and if all that increased time at high amps burns out the head or not......Proud to support Reliable Sheet Metal Works, in Fullerton, CA.Full service sheet metal fabrication serving Orange County since 1926.http://www.reliablesheetmetal.com
Reply:Originally Posted by soutthpawI thought that transformers on AC required balled tungsten and inverters required a pointed tip?   I could be totally wrong though.   would explain why he has problems keeping a pointed tungsten on a transformner...
Reply:insterno,You can get zirconiated tungsten (1/8") from tungsten-direct on ebay for about $44.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:Ooooh this is good to see, as I want to get a 20 series torch.  It's kind of like holding a pencil.. kinda nice.JoeMiller 140 Autoset (2010)Miller Syncrowave 250 (1996)
Reply:I have better luck with 1/8" tungsten on AC.  I usually use orange, but can't tell the difference except pure which I do not use.  I grind the tip like a D.    It works for me.   Surface tension of the aluminum is what trashes my tungsten.  (I dunk frequently)  I keep many sharpened on hand.DavidReal world weldin.  When I grow up I want to be a tig weldor.
Reply:Originally Posted by David RI have better luck with 1/8" tungsten on AC.  I usually use orange, but can't tell the difference except pure which I do not use.  I grind the tip like a D.    It works for me.   Surface tension of the aluminum is what trashes my tungsten.  (I dunk frequently)  I keep many sharpened on hand.David
Reply:I have bought a single piece of 1/8" Zirconiated tungsten before from my LWS.  You could try that before you start modifying torch parts.  And I have used it on a Dynasty 300DX welding 1/4 to 3/8 aluminum with a WP-18 torch at roughly 250 amps.  What brand is your WP-20?  I know the CK worldwide CK230 series torches are built for 300 amps and they are the same size as a WP-20.I play with Robots and do some welding.
Reply:I own a Lincoln Invertec, and for welding aluminum I use 3/32, 2% lanthanated (blue) tungsten, sharpened to a point, I did have to play with the a/c balance to be able to find that sweet spot on keeping my tungsten sharp.I use 100% argon.
Reply:Use zirconiated and adjust the AC balance to put more heat in the metal and less in the tungsten (less cleaning action) run 1/8 tungsten (should be easy to get collets locally or you need a new supplier, they are the same as the wp-9 torch parts)
Reply:Update with pics! Okay, so I got my 5/32" zirconiated tungstens and collets etc and did a test.Sample one, was on a Lincoln Precision TIG 275 full throttle at 340 amps with a 3/32" 2% thoriated tungsten. Sample two was on the same machine but with the 5/32" zirconiated tungstens. Lincoln set auto AC balance. Third was on a Miller Dynasty 300 DX at 300 amps with a pointed 1/8" 2% ceriated tungsten. Miller set 85% DC, at 120Hz. All welds were peddle to the metal, I didn't just turn up the machines to max for show. I ran them at the max too.I've included pics of the tungstens too. Of course the Lincoln just destroyed the thoriated tungsten it split and had a weird little shard hanging off the tip. The 1/8" pure couldn't really handle the amps, it shook violently, and over balled (oops the one in the pic was only used to about 220 amps) while the 5/32 zirconiated balled perfectly and held up very nicely. The sharpened ceriated tungstens hold up very well on the miller machine and keep their point very nicely.So, pics of the welds:Now, pics of the tungstens (3/32 thoriated, 1/8 pure, 5/32 zirconiated):So, if I had the choice, I'd use the inverter machine with ceriated, but for the inverter I really liked giant sized zirconated. Should have put a penny in for scale... I was welding a tee weld on heavy walled square tubing, and the welds are probably about a 3/8" tall.Last edited by insterno; 11-30-2011 at 07:42 PM.Proud to support Reliable Sheet Metal Works, in Fullerton, CA.Full service sheet metal fabrication serving Orange County since 1926.http://www.reliablesheetmetal.com