Gasless mig

[southernscouse]

Reading about these small lightweight inverter welders and watched a YouTube video says he can get good results by changing the unit to positive earth
A lot of the small welders are not fitted with a simple means of changing the polarity unless you open them up and change the wires over but will doing this effect any other parts of the welder ie the led display
Failing that has anyone had good results with gasless. Cheers

[clift_d]

The only gasless mig I've done has been with swapped terminals, i.e. positive to the earth clamp, as this was the recommendation of the wire manufacturer. Apparently it's what is termed as "straight polarity" (DCEN), and I found the results to be perfectly acceptable given the benefits of not having to deal with shielding gas. I've also done a little bit of gasless mig for stainless steel, with flux cored stainless steel wire, also with acceptable results. With my mig welder it's a straightforward job to set it up for DCEN by simply swapping over the final feed cables in the wire reel compartment, and it didn't effect the control circuits. Given that it's a standard operating procedure for gasless wire you would hope that even basic welders have a straightforward way of doing this.

More info on gasless mig can be found here:
https://www.mig-welding.co.uk/gasless-mig.htm

BTW, the mig-welding forum that you can reach at that link is also a really fantastic resource for all sorts of fabrication information, and well worth signing up for.

[davidoft1]

Gas less is ok, it’s a bit more work , more cleaning as it leaves slag over the welds , Havant motor factors supply gas and mig tig arc just off the top of the Eastern road , there are plenty small portable migs about too my migs 10kg , west ate you hoping to weld ?


The welders that are designed to have the polarity reversed have quick release cables , I would expect electrical issues if you reverse one not designed for it , you may even make the body of the welder live

[clift_d]

The welders that are designed to have the polarity reversed have quick release cables , I would expect electrical issues if you reverse one not designed for it , you may even make the body of the welder live

I have a Kemppi MinArcMig, which has a fixed torch and umbilical, and the terminals to switch polarity are not quick release, but they are readily accessible next to the wire spool and feed mechanism.



The key thing is that the welder manufacturer has made prior provision for the user to switch between DCEN and DCEP - I wouldn't recommend opening up a welder unit in order to ad-hoc something.

[southernscouse]

The reason I asked was I have been gifted a cheap inverter gasless only mig / arc welder which set up with meg earth and no provision to easily change pos/neg without taking it apart
Thanks for the replies (this is not for use on my camper but my 54 Austin van) cheers

[clift_d]

You can use gasless wire on a welder that’s set up as DCEP (negative earth), and plenty of people do so without issue. It’s just that the manufacturers suggest running it DCEN (positive earth) if you can for the best results. I would just give it a try, and consider doing some tests with similar gauge steel to get your settings optimised.