Reverse mig welder polarity

I have been given a Cebora 130 Turbo Mig Welder after a clean up it performs well with CO2 gas on car bodywork and light fabrications.

I have some reels of flux cored mig wire and would like to be able to use it but the polarity needs to be reversed to use it correctly.

Is there a simple way to convert the polarity I don't want to risk damaging the circuit board or wire feed.

Unless very straight forward I would have an electrician modify it or if the cost too high forget it.

Thanks for any useful information.

Paul

Edited By Windy on 17/02/2015 17:34:19

I wrote an article for MEW some years ago when I converter my previous Mig welder. The fumes are awful from the burnt flux so do it where the is a flow of air, some thing you can't do with gas. Send me a PM then if you have a circuit diagram I'll have a look to see if it is easily converted. I think its got to be a DIY job as an electrician charge would be more than the cost of another welder. Perhaps Neil can locate the actual issue number, I must have it some where.Ted

It was issue 132, Ted, and you wrote a letter clarifying something in issue 134.

How good is no-gas MIG? Do you get a layer of dead flux like with arc welding?

Neil

You simply need to isolate the gun feed wire and put a plug in the line. Do the same for the clamp wire then simply plug one into the other so that the polarity is reversed (that's very basic but its what you need to do). With regard to the flux wire, its good if you need to weld from the top of a set of ladders but the result for most people is just a mass of bird poop! Having said that if you keep the amps as high as possible and keep a tight weld it will hold things together, but doesn't look pretty. Not a good option for a live torch either.

> the result for most people is just a mass of bird poop!

Better than my stick welding then...

Neil

Here is a professional using flux cored mig wire

**LINK**

that self proposed expert is welding in the wrong direction...unless he is left handed!

When I moved home and downsized, selling my large SIP mig welder, I bought one of these Clarke no gas jobs. Not as good as the SIP mainly because of the very course controls, just two rocker switches high/low. The performance was acceptable but not good enough for finer work, say car body panels. The main advantage is the ability to use it outside where even a draught will destroy the gas welding.

Shortly after moving, a neighbour saw me using the mig and wondered if the flux coated wire would work on his Professional Cebora. By professional, I mean that like the SIP it was on wheels with provision for fitting a large gas bottle on the back. I fitted it up for him and although there was no polarity switch, I found the welding was easy and smooth. I put that down to the quality of the welder and the ability to use the controls for fine tuning.

On the Clarke welder, there is a small plastic tube for use with a mini gas bottle but I have not bothered to set it up. Nothing in the instructions about reversing polarity. Perhaps with the coarse controls it would not make any difference.

In regard to welding in the wrong direction this is from a Miller website.

Push or Drag?

With flux-cored welding, you should always use a drag (pull) technique, in which the tip of the welding gun is being pointed back at the weld pool and “dragged” away from the completed weld. An easy rule-of-thumb for remembering whether to use a push or drag (backhand) technique is: “If there’s slag, you drag.”

From what I have read some makes of cored wire can be used on both polarities but reversed polarity to gas shielded welding puts more heat into the cored wire for better penetration.

Edited By Windy on 18/02/2015 09:39:55

Hello Paul and other readers, as Neil has mentioned it was MEW issue 132 in which I described altering my SIP turbo Mig. I have looked on the site which you told me about Paul but the diagram is so faint as to hardly readable. By what little I can see the transformer and rectifiers are different and not sure about the micro switch feed either. Unless you have a lot of electrical experience I think leave well alone or try as Ray has done. I can send you a copy of 134 if you send me your email address via a PM. Ted/John

On my little MIG welder you just have to swap the earth and torch leads at the output terminals. These are clearly marked. It's a SIP Migmate. I use flux -cored all the time now, for light steel up to about 3mm, use gas for thin stuff eg car bodies, but hope not to have to do any more of that.

Cebora do a 130 gas /no gas Mig.

You need a different wheel as well as a different tip as no gas wire is thicker- the gas no gas one has two tracks of different size.

It has connectors for earth and power on the outside and you just swap them.

There is also a rocker switch that you need to operate - no idea why.

Mine came with fluxed wire awful stuff - went and bought a DIY small refillable bottle and ran it on gas even outside it's fine, you can use a lump of cardboard to the worst of the wind off.

If you test it with the gas off it sounds different and looks bad, all you then do is turn up the gas till it sounds better and looks good.

Do not buy disposable cans of gas they are way too expensive

My early Cebora 130 does not have a no gas facility changover.

I did a test with the Cebora using flux cored but with wrong polarity the result was a sound weld but a lot of weld spatter.

According to **LINK** wrong polarity with cored wire causes more spatter but you can weld with it.

Will try a friends flux cored wire Mig with correct polarity and compare results.