220 v. SMAW on 110v.????

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HI:  I recently bought a Craftsman 300 amp (antique) box at a garage sale.  Dirty, but looks functional.  I intend to use it for light fabrication, and also for brazing with an arc-torch, neither of which require much current.  It's a 220v. unit, but I have only 110v. outlets in the garage.  I'm thinking it's OK to run it on 110v. PROVIDED THAT only low current is used, and I'd have to divide the current markings by 2.  As a ROUGH estimate, it's rated line current draw at 220 is 1/4 the electrode current - same for 110v., as the transformer ratio is the same - which means a limit of 60 amps at the electrode on a 15 amp 110 v. circuit...  right???  Also, I would install a 110v. fan to maintain cooling.  I have read posts by others about running a long extension cord from the dryer or stove - could do that, but if it's not necessary, why bother?  I know this is somewhat half-baked, so thanks in advance for your help...
Reply:Few problems with your thoughts. On most multi voltage machines when you lower the voltage, say from 440V to 220v you almost always double the amps to run the machine. That machine will want 50 amps most likely on 220V. Good luck finding a 100amp 110 breaker. Now 15 amps at 110 coresponds to 7.5 amps at 220V using the same principal. That machine probably won't weld on 15amps of 220v, let alone 7.5 amps. Also transformers eat a large amount of power just sitting there idleing, so linear math doesn't work on power consumption.The electrical gurus will probably correct my rough thoughts and explanation above, but the reality will be the same. THE MACHINE WON'T DO SQUAT ON 110V.  Period!.No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:Run an extension cord from the dryer outlet.Machine was designed to run on 220v.  Don't waste your time trying to make it work on 110v.  Not going to accomplish anything, except maybe burning out the machine.If you want a machine that runs on both voltages, there are machines that do that.  The Maxstar 150S is one of them.  Nice little machine too.MM350P/Python/Q300MM175/Q300DialarcHFHTP MIG200PowCon300SMHypertherm380ThermalArc185Purox oaF350CrewCab4x4LoadNGo utilitybedBobcat250XMT304/Optima/SpoolmaticSuitcase12RC/Q300Suitcase8RC/Q400Passport/Q300Smith op
Reply:How about if I plug my 110 MIG into 220?  I should be able to weld 1/2" plate single pass, right?  What you want to do is kinda like trying to run a gas engine on diesel, or vice versa.  Not set up for it, ain't gonna be happy with the results.Give the machine what it wants... 220 volts!Last edited by Leadhead1911; 10-21-2009 at 10:16 AM.Work HARDER, not smarter! ------------------------ Miller Bobcat 250Millermatic 251Lincoln Precision TIG 185Hypertherm PM 600Hobart 135 HandlerOxweld 400 FlameMaster