Is a mig AC or DC?

[pavetim]

I have a dual mig/flux core welder. It says it's 240VAC. I know thats input voltage but is it AC output or do mig's have an ac to dc inverter? I'm trying to see if I can use a spool gun on it to weld aluminum or if I have to find an inverter.

 

[shenion]

Most MIGs are DC. There should be a set of terminals to set polarity for gas/gasless. Torch positive for gas.

Some real cheap gasless ones are AC. The Dual MIG should be DC. It is not an inverter, just a transformer and rectifier.

 

[pavetim]

Oh ok so I can't use a spool gun cause it's dc. Have to see if I can find a dc to ac high freq inverter I guess. Don't have money for a HF tig right now.

 

[Paul.]

DC mig is good for all materials, AC is used for TIG welding aluminium, a spool gun will work fine, assuming it physically suits your machine

 

[shenion]

Like I said the Dual MIG should be DC. I checked the manual and it is DC.

 

[backpurge]

Some real cheap gasless ones are AC.

And also some very expensive, highly sophisticated ones mate

 

[Delgado]

And also some very expensive, highly sophisticated ones mate

Like THIS one.. A snip at $10,000.00, I'll take 2!

 

[backpurge]

Like THIS one.. A snip at $10,000.00, I'll take 2!

Have used the OTC kit quite a bit and have to say for thin material and gap bridging they are in a league of their own, you can alter the wave balance in the same way you can with square wave TIG, superb, yes they are dear but it's horses for courses

 

[Delgado]

Have used the OTC kit quite a bit and have to say for thin material and gap bridging they are in a league of their own, you can alter the wave balance in the same way you can with square wave TIG, superb, yes they are dear but it's horses for courses

OTC isn't a brand I'm familiar with, but it looks like good plant, and sounds it, from what you're saying. Also, I guess they're not that pricey if you compare them to other top end sets from the other big names.

Just for my own curiosity, How does it 'feel' when you run a weld with AC compared to DC mig, is the fact that they're AC noticable or do they just handle better on gaps and thin stuff? Does the fact that they're AC provide any cleaning action on Ally? and would they also be suitable for running xray quality root passes in pipe, like with say your STT type machines?