Check yer water

Last time I used my TIG on a very small job, I noted some steam. Uh-oh! Put a note on the torch to check that before using it again. I got around to checking. Pulled a line off the cooler. No flow. Uh oh. Applied air pressure both directions. Cooler bubbled, air flowed into the torch line. Lookin' good. Added some water, hooked everything back up with the feed line loose. Powered up. Got flow into a bucket. Awright, the pump is still good! Hooked that up, powered up again. After running for a minute, a puddle appeared under welder, but I didn't see it until it had crept out and was sloshing my shoe. Aw, crap! Two things I strongly dislike on me are antifreeze and tranny fluid. I'd about rather roll in pigshit. Well, I say that having never rolled in pigshit, but while stinky it's can't be any more slimy than antifreeze or tranny fluid and it's gotta be easier to wash off.

The supply line mit water-cooled power cable within had a ... uh... linear aneurism. Split like a banana with the air pressure I'd applied. The 10 gage bare stranded wire within (for 250 amps!) had overheated without water flow and hot-wire-cut nearly thru the vinyl tubing. That wire can handle the welding current just fine as long as there's water flow, and I figure the voltage drop at 250 amps to be less than 3 volts which is negligable for a TIG machine. The welder came with that setup and it'd welded many stainless steel silos in its previous life. I suppose light weight is a plus when welding a silo a fair ways above ground. It's also a plus for welding at my bench.

Disassembled, took to welding store to have John cut off the bad part and crimp on a new fitting. NOT! "Gotta buy a whole new one, Don." I guess I coulda kludged it, but it looked like more than $38 worth of screwin' around even for this frugal Finn, so I popped for the new one.

Got everything put back together, which included unsnapping about 100 snaps on the leather shroud by prying each one with a screwdriver, then resnapping with a big pair of pliers. Clean up mess -- yuk! Add water to cooler reservoir. Took a gallon and a half of distilled water. I guess it was a bit low. Don't know how that could have happened since I filled it up in 1995...

I'm TIG'in again.

Check yer water!

Reply to
Don Foreman
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How about adding a flow switch to the return line, so NEXT time it will alarm you about missing cooling water flow.. Some TIG machines have input for such switch, and switch off welding current when there's no flow, but otherwise a solution would be to put a large "buzzer" (that surplus air-ride -horn:) connected to the flow switch, and/or a power-relay what allows power to the TIG machine only when there is cooling water flow..

Kristian Ukkonen.

Reply to
Kristian Ukkonen

Whoa! 250A in 10ga is 40 circular-mills/amp (inverse of current density). 400-1000 c-m/A is used in Mil-std design and 250 is OK for single wires in free air! I guess that it would overheat!

250A in 10ga is kinda hard to get an intuitive feel for, so consider that 250A in 10ga is the same current density as 25A in 20ga!

Bob

Reply to
Bob Engelhardt

Good idea. Just a flow sensor would be enough. I'm the only one that uses the welder.

Reply to
Don Foreman

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