Originally Posted by Scout
We are about to buy a welder. Any suggestions?
If you are mainly wanting it to weld armatures together I would suggest looking mostly at MIG welders. These tend to be the most convenient for assembling complex structures, especially if you are doing a lot of tacking and welding of relatively thin rod, bar and plate. It's also the easiest process to learn for most people.
I would stay away form the very cheap end of the market but there is also no real need to spend a lot on a big brand industrial model either.
A good general indicator of quality is the duty cycle, and check whether figures quoted are at the maximum operating power. 160 to 180 amps should be more than adequate for most jobs as long as the duty cycle is ok. Something like 35% or more at full power is fine. Beware that some of the cheaper manufacturers quote duty cycle figures in a way which, if not factually incorrect, is a bit misleading.
Models with digital control which automatically matches the wire speed to the voltage is useful and saves time but is not essential and in general inverter based machines tend to be a bit easier to use than transformer based ones. In terms of buying I would look at specialist welding suppliers rather than the more general purpose tool retailers.
A stick welder is the other alternative and they do have the advantage that you don't need to worry about gas bottles, and are a bit cheaper to buy and run, but for the type of work you are talking about they are likely to be less easy to use, especially if you're not an experienced welder.
Something else to look out for is the ability to reverse the polarity, this allows you to use flux-cored wire which behaves in a similar way to stick welding. It tends not to be as neat or easy to use as gas shielded welding but can be a useful standby if you run out of gas and performs better outdoors (as well as making the machine more portable) and copes better with welds where it is impractical to properly clean the joint.
You can now also get multi-process machines which will do MIG, stick and DC TIG in one package (although in some case you may need additional accessory kits to get the full functionality). These are worth considering is you think you might do a wide range of different processes but are a bit more expensive than the single use machines of equivalent quality.
It can also be good to get a machine with a detachable torch assembly. The torch parts do need occasional maintenance and part replacement and this is more difficult on the hard-wired torches. But not a deal breaker is you just want an economical machine. It also makes life much easier if you ever want to weld aluminium.
The high end machines will tend to have features that you won't really need for small scale jobbing work and these tend to be geared more towards increasing productivity on industrial production rather than actually producing better welds.
Personally I would go for a mid-priced inverter based machine from a reputable brand, with MIG welders it is definitely worth spending a bit extra to get a decent mid priced machine as opposed to the budget models.