Mig vs Arc - Amperages

[anto]

Apologies for what might be a daft question and possibly also in the wrong section

Will a 160amp mig machine weld the same thickness of steel with the same penetration as a 160amp Arc machine. (All other things being equal and that the machines are achieving the full 160amp).

Thanks,
Anton

 

[Drains]

No.

A 160a Mig welder will be running at lower arc voltages, so the total power put into the weld will be less.

You can run a (let's say) 180a Mig on a 13A plug, but a 140A (transformer) arc welder will blow a 13A plug at full current after a minute or two.

The thing about arc is that if you have current enough for the size of electrode you are using, you can weld any thickness of metal. You might have to run multiple welds in order to build up the correct thickness, but though it takes longer, it still works. A 140A arc inverter welder will run 3.2mm rods all day.

To be able to do the same thing with a Mig you need at least 200A and you need a good duty cycle to go with that or you'll spend plenty of time hanging around waiting for it to cool down.

And it's not a daft question

 

[rich r]

Another way to look at it- with a mig welder, you're probably using 0.8mm wire, so the arc is around 1mm wide. At 160A with an arc welder you'd be using 4mm rods - the arc is massive in comparison, generating a huge amount of heat, and depositing a huge amount of metal from the electrode as well in comparison to the thin bit of wire in mig.

 

[anto]

Thanks guys for the answers.
So in real terms my 160amp mig would probably struggle with 6mm plate to achieve full (if any) penetration but a 160amp arc would deal with it easily or at least a lot better?

Rich r - i never thought about it in "arc size" terms before.

 

[rich r]

You can very easily weld 6mm plate with 80A and 2.5mm rods. A £30 buzzbox will have no problem doing that (I know, because I taught myself to weld with 2.5mm rod, 6mm steel plate, and an Aldi buzzbox )