electrical question (amperage)

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Hello, Please help me with an electrical question.I have a precision tig 185 and was wondering if I replace a dryer recpetacle with my welder receptacle and run it on the circuit, if I will be okay. - I understand the hazards of running the wrong wire and all of that. However, I am guessing the dryer is either 20 amp or 30 amp, and the wire will be #12 or #10. Now, I am assuming if I leave everything alone, it will not pose a fire hazard as long as the same wire is left in with the correct breaker. - I am assuming the 20 or 30 amp breaker would trip when the welder was too much for the circuit?  - and since I rarely have my machine above 70 amps, I doubt I would ever trip that breaker. - is this safe? - I would run #6 wire and run the right set up, but I am in a town home, and I do not own this place. Is a fire hazard only present when you run a small wire and too large of a breaker? - I could call my father, he is a certified electrician and a damn good one, but I will probably get an answser faster this way!! Thanks!!
Reply:Howdy!  I see a rated current draw of 64 amps from this machine.  No this is not safe.  you would nead a range supply, to be close to adequate.  8-3 Cu, prefererably 6-3. or 6-3 Alluminum to 4-3 alluminum.  Gotta go... good luck.  Brian Lee  Sparkeee24
Reply:Thanks Sparkee. I understand what you mean and the amp draw, but if you have a 30 amp plug, #10 wire, and a 30 amp breaker, would the breaker not trip once you exceeded the safe zone?? - I know I can not weld thick, but would I still not be safe because the breaker would trip when the circuit was overloaded???
Reply:Some dryers are on as much as 40 amp breakers.  I ran a 180 amp lincoln tombstone welder on drier and stove circuits for years as a kid.  The breaker will tell you when you have exceedd the limit.  In my day it was fuses and I never had to replace one.  I still remember the concerned looks of parents of my buddies when I would bring over the welder and splice into the fuse box.
Reply:You are correct in that if the outlet was properly wired for the rated current of the breaker then the breaker would trip before a fire hazard ensued.  If you never ran your machine over 70 amps, then I doubt there would be a problem.  However, a dedicated circuit might serve you better in the long run.
Reply:Howdy!  As an electrician, I will tell you don't do it.  As a real world make it work point of view, you SHOULD be safe.   it has been my experience with these style recepticles, that the first place excessive heat will buildup is at either the breaker connection to the conductor, (less likely), or where the plug is inserted into the recepticle. ( more likely)  A breaker usually only trips immediately from a fault to ground, or bolted fault.  Past that it trips from heat build up at the breaker, or if it's run too high amps for some time.  The best place to keep an eye on, is the temperature of the recepticle your plugged into after using it at the highest setting, YOU will use it on.  It is common, and fine if it is say, 10 degrees warmer then ambient air, but much more then that, and no good.  A person can not relie on a breaker all the time as the means for determining if your drawing too much from that wire.  And, it all depends on the condition of the panel and breakers within.  i don't know of anyone who would suggest your plan with a federal pacific, or Zinzco panel.   This is where I was coming from.  I know of many places with the correct breaker sizing for the wire, where the neutral was turned brown like burned toast, and insulation cracked off, yet the correct size breaker did not trip.  This was mainly from an un-balanced load, and incorrectly setup panel.  But he wanted to know if it was safe.  This has been my opinion.  I would do it in my house, but not suggest a friend to do it in his.  Good luck.  Brian Lee  Sparkeee24