Welding Machine

[Harmiabo]

I would like to buy a Welding Machine.
I dont need such a heavy duty thing

I found a used one and I am not sure if I should buy it or not because I dont know much about these machines.

This is in French but you can get a good idea of what it is
Description générale
-SOUDEUSE DE MARQUE AIRCO. -INSDUTRIEL HEVY DUTY. -300 AMP AC/DC MSM BUMBLEBEE. -VOLT: 230/460/575. -AMPS:100/50/40. -DUTY CYCLE 125%. -VENDU AVEC ROD BRAKER 100 AMPS -LE FILS DU WORK NON INCLU. -PARFAITE ÉTAT DE MARCHE TRES BONNE MACHINE MONTÉ SUR ROULETTES.

He says the price is negotiable and the wires are not included and it is in good condition

Hw wants 300 dollars candian and it negotiable

I would like to use it for things like making a furnace and also welding some steel bars
Thanks

[Fred_V]

Be sure to get one with DC welding as this one is. DC is easier to make good welds; doesn't stick the rod as badly as AC does. My welding improved 100% when i got a DC machine.

[warmstrong1955]

All the old Airco machnes I have been around, were Millers painted orange. Not sure if they are all like that though. A dealer I bought our Millers from in the 70’s also was an Airco dealer. They quoted both, and the Aircos cost more for the same thing.
I think they were bought by ESAB.

They were good welders, after all, they were Millers in disguise!

[duckman903]

The only problem that I see is the amperage at the higher welding amps, the welding leads (what you call wires) can be expensive, when and if you get it get the twist to clamp electrode holder much better than the grip clamps. JMPO

[johnfreese]

The Airco industrial welders were well made. As a 300A , 125% duty cycle machine it is unlikely the previous owner overheated it unless he was doing seriously heavy fabricating. One suggestion: check the availability of replacement diodes.
It is capable of burning a 3/16 E7024 electrode although you would likely never want to.

[SteveHGraham]

What is the point of a 125% duty cycle? That's a new one on me.

[Steggy]

I would like to buy a Welding Machine.
I dont need such a heavy duty thing

I found a used one and I am not sure if I should buy it or not because I dont know much about these machines...DUTY CYCLE 125%...

Is that a misprint? The maximum possible duty cycle would be 10 minutes welding per 10 minute period of being powered on, in other words, 100 percent. Only a machine intended for production welding would have a 100 percent duty cycle at full output.

[SteveHGraham]

Maybe it's used for welding the frames on time machines.

[Pontiacguy1]

It usually means that it can actually be run in an overload of 25% and not be hurt. Don't know if that's correct for this welder or not, but sometimes you find electrical motors rated that way too. I bought a 1 HP motor a few years ago that said it had 120% duty cycle, which I took to mean that it could actually produce 1.2 HP without overheating and burning out. Usually only really heavy-built industrial grade stuff is made like that. I guess they assume that it will be abused and overloaded by some jack-wagon who doesn't care, so it's built tougher to take more abuse.

[NP317]

I have an inverter welder that states "125%" load capability.
I haven't tried to push it that hard...yet.
~RN

[Steggy]

It usually means that it can actually be run in an overload of 25% and not be hurt. Don't know if that's correct for this welder or not, but sometimes you find electrical motors rated that way too. I bought a 1 HP motor a few years ago that said it had 120% duty cycle, which I took to mean that it could actually produce 1.2 HP without overheating and burning out. Usually only really heavy-built industrial grade stuff is made like that. I guess they assume that it will be abused and overloaded by some jack-wagon who doesn't care, so it's built tougher to take more abuse.

How does one "overload" a welder? Any welder's design makes it intentionally self-limiting with respect to output power. The key variable is the duty cycle rating as a function of output. By definition, the duty cycle cannot exceed 100 percent—it's a time thing, y'know. The duty cycle is expressed as what percent of a 10 minute period can be used to actually weld. A 25 percent duty cycle, for example means it is safe to weld for a maximum of 2-1/2 minutes in any 10 minute period, with the balance of the time required for cool-down.

My MIG welder, for example, has a 100 percent duty cycle up to 150 amps output, decreasing to a 60 percent duty cycle at maximum output (250 amps). So at full power, I can weld continuously for six minutes and then must let the machine cool for four minutes before resumption of welding. The only way the machine could be "overloaded" would be by not observing the 60 percent rating at full power, which would result in overheating and possible failure (it has a thermal cutout to minimize the likelihood of thermally-induced failure). No matter what, the unit will not produce more than 250 amps when the "heat" control is turned to the maximum.

Electric motors, on the other hand, can usually be loaded beyond nameplate ratings for a certain amount of time. The ability to tolerate such usage is defined by the motor's "service factor," which will be at least 1.0 for a continuous duty motor. A service factor of 1.15, which is fairly common with three-phase motors, means the unit may be loaded up to 15 percent beyond its nameplate horsepower rating, although the length of time this can be done without overheating the motor isn't always specified. This is completely unlike a welder, which cannot produce more than its rated output, even into a dead short.

[SteveHGraham]