Polarity

lowlyslows · Mon Mar 27, 2017 8:52 am

Hey all,

Can you weld in DCEN with Mig and gas? I have done it on thin metal and it seems to hold. Long story short, I have replaced a bunch of metal on my old car and just realized that the machine was set to DCEN instead of DCEP. Now I am worried about strength.

Thanks

Farmwelding · Mon Mar 27, 2017 10:29 am

My simple answer is no and there is no need to. DCEN is reserved for self-shielded flux core wires. Much like stick welding, DCEN provides less penetration. For thin metal this would be less of an issue. Sheet metal (thinner stuff like 16 gauge for those who weld big stufff) for instance doesn't require penetration like 1/4" since there is less strength and it is generally under less force. So for all purposes you should run DCEP on all short circuit mig and spray transfer and dual shield flux core. I'm sure some one has an exception but for the 99.9% of us it is DCEP.

lowlyslows · Mon Mar 27, 2017 10:36 am

Farmwelding wrote:My simple answer is no and there is no need to. DCEN is reserved for self-shielded flux core wires. Much like stick welding, DCEN provides less penetration. For thin metal this would be less of an issue. Sheet metal (thinner stuff like 16 gauge for those who weld big stufff) for instance doesn't require penetration like 1/4" since there is less strength and it is generally under less force. So for all purposes you should run DCEP on all short circuit mig and spray transfer and dual shield flux core. I'm sure some one has an exception but for the 99.9% of us it is DCEP.

Thanks for the answer. So with all the welds I have done with it set to DCEN, should I be worried?

Farmwelding · Mon Mar 27, 2017 10:39 am

well... that depends on material thickness. If you have been doing some sheet metal work then I wouldn't worry, but much thicker I may reconsider. Also you may want to consider the use of the weld. Trailer-bad plan. Shelf that holds minimal weight-wouldn't worry.

Edit: I am no expert on testing, inspection, or metallurgy so my word is not gold on this matter.

cj737 · Mon Mar 27, 2017 10:53 am

lowlyslows wrote:Can you weld in DCEN with Mig and gas? I have done it on thin metal and it seems to hold. Long story short, I have replaced a bunch of metal on my old car and just realized that the machine was set to DCEN instead of DCEP. Now I am worried about strength.

That's pretty odd that you were able to get the wire to weld. If the body panels are "cosmetic" and not "structural" I guess you be okay. If it were me, I would correct the settings, grind back most of what you have done, that spot tack back in properly. I would not expect the welds to hold up over time. Maybe I'm wrong

lowlyslows · Mon Mar 27, 2017 11:38 am

cj737 wrote:
lowlyslows wrote:Can you weld in DCEN with Mig and gas? I have done it on thin metal and it seems to hold. Long story short, I have replaced a bunch of metal on my old car and just realized that the machine was set to DCEN instead of DCEP. Now I am worried about strength.
That's pretty odd that you were able to get the wire to weld. If the body panels are "cosmetic" and not "structural" I guess you be okay. If it were me, I would correct the settings, grind back most of what you have done, that spot tack back in properly. I would not expect the welds to hold up over time. Maybe I'm wrong

Yea, some of the welds were for frame parts. It won't take long to fix/redue.

Thanks guys