Hi Dave,
If you buy a wire fed welder with an output of 130 amps, you can expect to weld up to 3/8" steel using an open arc wire. With a 20% duty cycle, you can run a bead at full output up to about 14" in length before the machine shuts down. The open arc wires will add heat to the welders output. Preheat can be utilized to expand the thickness capabilities of any welding process but is not always practical. Buy a big enough machine to do what you need from the start. 130 amps will only weld 1/8" aluminum at best. Sometimes people refer to gas shielded welds as being cleaner. Actually, a cleaner more sound bead is often realized with open arc wires under certain conditions. The deposits made by the gas shielded wire should be cleaned with a wire brush before making a second pass. This is true of my wires or anyone elses. Many of the cored wires such as our #824 can be multipassed up to three time w/o removal of the slag. One reason for this is the ability of the flux to float impurities to the surface of the deposit. This is the same reason open arc wires produce cleaner welds in contaminated environments. There will be noxious gases produced by both shielding methods. Although not visible, the gas shielded plume emits ozone gas and carbon monoxide gas from the CO2 being passed through the arc. There are other toxins produced in addition to those two. I don't believe anyone uses copper windings anymore. Many manufacturers use a coating on the windings that resembles copper when you look at it. (That's not the reason the coating is used.) You should also be aware that Miller and Hobart are both owned by the same parent company. There are many alternative choices available in todays market for both welding machines and consumables. HTH,
Steve
| 
