TIG torch cable voltage drop?

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Hi, I've been looking at tig torches in both 12.5' and 25' lengths.Looking at the power cable, both look really thin, and considering that the water is coming back through that same cable/hose, it is going to have even less actual wire.The one I'm looking at is a 350 amp torch, and the cable is shockingly (no pun) thin.  Seriously, that must have some considerable voltage drop at 350 amps.  Has anyone with a 25' cable measured the voltage drop at full current, or have any other insight on the matter??Thanks.
Reply:TIG supplies are constant current.  The voltage drop doesn't really matter.
Reply:you are using the water as a conductor also ?
Reply:Don't worry about it, just weld 'er up! Get the long one. Do you really need the 350A torch? The 250A is pretty common and handles up to 300A easily. The 350A version is much bigger and bulkier.
Reply:You shouldn't have to worry about the voltage drop on a 25' torch unless it's some kind of El'Cheapo version from a third world country ...LOLAs Alanaker stated above, A 350 amp torch is a pretty large torch.... Now. .. ... no screaming from the peanut gallery guys. .. .... I know there is someone out there that could probably use a 500amp torch and it not be big enough.... BUT !Personally most of my welding is light gauge Stainless Steel and I use a Weldcraft WP-9 125 amp and it's more than enough for what I do, but I don't do any kind of production welding ... All said it depends on what you are going to be welding ... Washman
Reply:Thanks for the responses...76GMC1500;It is quite true that TIG machines are constant current, however, like anything else, they are power (wattage) limited, and any power lost in the cable translates to lower maximum possible output current.prop-doctor;Is that a statement or a question?  The question mark throws me off.  I had thought of the possibility that the water could be conductive, but was not sure.  Under normal conditions, distilled water is not going to be conductive, but inside the electrified cable... it's not normal conditions.alanakerI wanted the 350 because it is the largest torch that I see commonly available that simultaneously has commonly available and cheap consumables.  If I normally only used 250 amps, I would be running that torch at 100%, whereas with a 350 it would only be running at around 71%.  Moreover, I generally prefer to have the capability to go beyond what I expect to need thus I have a higher likelihood of always having what I need, and lastly, my welder capable of producing 405 amps, and I might as well have a torch that could at least get close to handling it.  I would have gone for the 500 amp torch, but that sucker's consumables get kinda spendy.WashmanI have not seen a 125/250/350 weldcraft side by side, and so I cannot speak to those.  I have a POS (not weldcraft compatible) TEC 428 (350 amp) tig torch sitting here, and it does not seem overly large, but again, I have not seen a small torch (150A?) up close, so I have nothing by which to compare it.  I have a 200 amp AC stick machine that the dinosaurs probably kicked around a bit, and at something below 200 amps, it will blowholes in the thickest piece of metal I have ever welded (I seem to usu do thin stuff), but as I said above, I like to have options.... not expect to use it, but nice to have the ability should I find a need for it in the future.Oh, well, I hear people comment about losing the air "cooled" tig torch and getting a water cooled tig torch.  If the thin-ness of the cable and length (25') were a problem I suspect that people would lament that as well.Thanks.
Reply:Tha small size of the water cooled cable is a result of requiring less copper in the cable because it is cooled by the flowing water.  The water is not contributing any conductivity to the cable.  Any conductivity of the water due to impurities would be miniscule compared to the copper.You can determine the actual voltage drop in the cable by referring to standard tables of resistance per foot for the various wire guages.  For standard wire alloys, the resistance of the wire, and thus the voltage drop and power dissipation for any particular current, is purely a function of the wire gauge.Yes, a smaller wire in a water-cooled cable will have a larger voltage drop at a given current than a larger air-cooled cable.  But, no, I do not think that the voltage drop in a water-cooled TIG cable is a significant factor in torch performance unless you were going flat-out requiring max power from the machine.awright