Water cooled torch doesn't weld right

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Here's the story: I recently removed the old air cooled tig torch from the ancient Hobart CyberTIG here @ work and replaced it with a water cooled torch and cooler unit that I found in the back of our storage building. After a lot of scrounging of flare fittings to connect it all, and a good cleaning & refilling the cooler with a 50/50 mix of water & antifreeze, it welds! I've been using it to weld caps & bungs on some 0.065" wall stainless heat exchanger shells. However, I've noticed that I had to turn the amperage waaaaay up for it to weld with any jam, it's currently set on the 5 to 300 amp range and approximately 60% (which should be about 180 amps) on the weld current dial. If I change the amp range selector to 5~100 amps and max the weld current dial (which is where I used to set the machine before the torch swap), I can floor the pedal and it barely makes a puddle. What's happening? Any clues or advice would be much appreciated
Reply:You didn't connect the power block of the torch hose back to the cooler with something electrically conductive, did you?
Reply:Yes, check to see if the power block is grounded to the chassis.Has happened to me a couple of times.Weld like a "WELDOR", not a wel-"DERR" MillerDynasty700DX,Dynasty350DX4ea,Dynasty200DX,Li  ncolnSW200-2ea.,MillerMatic350P,MillerMatic200w/spoolgun,MKCobraMig260,Lincoln SP-170T,PlasmaCam/Hypertherm1250,HFProTig2ea,MigMax1ea.
Reply:Y'know I wondered about the power connection, the torch has two lugs, one of which is clearly the power lug for the torch and another smaller lug that was connected to the return line of the torch, which then goes back to the cooler. I bolted them both to the power lug of the machine. Should I disconnect the return lug perhaps? Maybe instead of muddling through an innaccurate description I should take a pic...
Reply:Ok here we go, promise not to laugh! Attached Images
Reply:Gas looks fine. But I would remove the "water from supply" line and connect right to the power block, bypassing the soloniod valve altogether. That is only for city water.And take that black coupler block off the power block lug. It just might be doing something. That way you are isolating the arc current just to the power cable, and ground lead.Last edited by shovelon; 01-24-2012 at 04:16 PM.Weld like a "WELDOR", not a wel-"DERR" MillerDynasty700DX,Dynasty350DX4ea,Dynasty200DX,Li  ncolnSW200-2ea.,MillerMatic350P,MillerMatic200w/spoolgun,MKCobraMig260,Lincoln SP-170T,PlasmaCam/Hypertherm1250,HFProTig2ea,MigMax1ea.
Reply:The bottom brass lug should be the only thing attached to the machine..Take the top adapter off and let it hang in mid air.....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:I took the small return lug off the power connection as per the suggestions and it seems to have a lot more jam @ 100 amps. Some of the bungs I'm welding into the 0.065" tube shells are sched 10 pipe and it still seems like it needs a tad more juice, but welding the end caps on the shells is no problem now. I think that stupid lug was the issue, thanx for all the help guys!
Reply:Hello Mechtician, your picture with the "X-tra" lug assembly on it that has something to do with the cooling water, would have provided a path for the electrical energy to dissipate to ground or else somewhere that might have lit you up a bit if you touched the machine incorrectly. I believe, as the other posters stated, that your removal of that lug from the power lug on your welder was indeed the correct move. Did you notice anything unusual with how the HF was working? I would additionally surmise that if you tried welding on aluminum with your machine in it's previous configuration that you might have had some interesting results. Good luck and best regards, Allanaevald
Reply:I haven't welded any aloooominum since I swapped torches, but as far as the HF is concerned it's been behaving strangely ever since I started using the machine. Basically, it stutters badly and won't light up unless the tungsten is almost touching the workpiece. I find most times I'm performing more of a scratch or lift start than a HF start. I've tried everything I could think of (turned the gas flow down as low as possible, changed ground locations, changed collets & collet bodies, changed tungstens, checked the spark gap inside the machine, etc etc blah blah blah) but it still behaves the same way. I've just learned to work around it, none of the welding I do is x-rayed or required to hold much more than 10 psi of internal pressure, and once the arc is lit the old girl welds fine, so I just gave up trying to fix it
Reply:The water supply from the pump should actually go to the torch head first, the smaller left-hand-thread hose connector, and the return to the pump from the power cable. This will give your torch head the most cooling possible. And as stated earlier, don't use the machine's solenoid valve for a coolant pump. It will cause the pump to dead-head.
Reply:are you using low-conduction coolant?Experience is something you get right after you need it
Reply:Originally Posted by welds4dThe water supply from the pump should actually go to the torch head first, the smaller left-hand-thread hose connector, and the return to the pump from the power cable. This will give your torch head the most cooling possible. And as stated earlier, don't use the machine's solenoid valve for a coolant pump. It will cause the pump to dead-head.
Reply:The Thermal Arc coolant is deionized out of the jug. We have an older Thermal Dynamics plasma cutter that is water cooled and requires that coolant. It has a deionizer cartridge built in to the coolant system. I haven't seen a deionizer on a TIG torch cooler (not saying that they aren't out there). I use the same coolant in everything, because I have it on hand.
Reply:I just looked up the manual for the unit (it's a Thermal Dynamics HE100A) and it does state specifically that deionized water with a resistivity value of greater than 0.1 megohm is to be used as coolant. It also sez that there's a deionizer built into the unit to maintain resistivity of the coolant, but the DI cartridge is missing on my unit, probably junked a long time ago. In any case, thanx for the pointers and advice, much obliged gents!
Reply:Really, the DI water is more about HF performance,  I have had a couple of rare instances where the HF start was weak, and replacing water as a coolant with the right stuff helped quite a bitExperience is something you get right after you need it
Reply:Originally Posted by zapsterThe bottom brass lug should be the only thing attached to the machine..Take the top adapter off and let it hang in mid air.....zap!