ac/dc

[mikedeere]

Hello, I have welded DC a Lot. But I haven`t used AC much. Is there a BIG diff. And what is the Difference Thanks:confused:

[blue&gray]

I was curious myself and found this info on Millers site.

. Penetration: DCEN - Least penetration, AC - medium (can be more spatter also), DCEP - most penetration.

After messing around a bit with mine there is also some difference is ease of starting an arc in DC.

[Go1lum]

Depends on the process. AC typically like for stick welding is used to avoid arc blow. Tig ac typ for AL. Give us more info on the process and we can provide more info

[Matthew]

for some metals you have no choice. welding aluminum? you need the AC current to break through a layer of oxidation on the surface of the aluminum.

[Go1lum]

I was curious myself and found this info on Millers site.

. Penetration: DCEN - Least penetration, AC - medium (can be more spatter also), DCEP - most penetration.QUOTE]



QUOTE=Matthew;209445]for some metals you have no choice. welding aluminum? you need the AC current to break through a layer of oxidation on the surface of the aluminum.

You don't have to have ac for AL. DC- with 100% helium and clean Al works just fine.

That depends on the process. in some cases DCEP is shallower penetration.

[kbnit]

" Penetration: DCEN - Least penetration, AC - medium (can be more spatter also), DCEP - most penetration."

This is referring to stick welding.

[Jolly Roger]

for some metals you have no choice. welding aluminum? you need the AC current to break through a layer of oxidation on the surface of the aluminum.

Regardless of the current you use when tig welding Al you always clean the oxide layer off before welding. Otherwise you are making a contaminated weld.

Ac is preferred for tig on aluminum because the arc has a self cleaning action which helps to combat the rapid oxidation of the metal. But is not a requirement and it requires much more power then dc when you get into larger material.

Mild steel can be easily welded with sticks and ac. There is a difference in the amps required. Ac sounds a lot different, is a bit harder to get started, and works well on magnetized steel. I've used it quite a lot and it doesn't make much difference to me if the machine is ac or dc as long as I have the correct electrode. Most all DC electrodes will run on ac but there will be an ac equivalent. Any electrode that will run on ac will run even better on dc.

All Mig is dc.

Hope that helps. BTW the manufacturer has the info on what currents any particular electrode they manufacture can be used with. Ex. - 6010 is straight dcep (dc+) while 6011 may be run using ac, dc+ and dc- and the same for 7024. 7018 is ac or dc+.

[mikedeere]

Thanks, I welded with AC many years ago but I just haven`t used AC since I started using DC, The reason I ask is that was thinking about getting an engine drive and they are cheeper in AC.