Converting "gas" Mig to use flux wire

Date 01-27-2003 19:43

I have a "hobby" Mig (It is badged as a Snap-On 130 but I think the guts are Cebora) which is a "gas only" unit. I would like to try flux cored wire but realise there needs to be a polarity change. Is it simply a case of reversing the connections to the torch and earth lead or will the electronics be fried if this simple reversal is performed ? (the unit is old so there are no guarantee issues assuming I can modify the unit as described above).

ps. Great site

pps. I looked at a "dual" welder in Harbour Freight last night and to change polarity you reverse two cables which are attached to isolated studs located in the area of the welder that houses the wire/transport mechanism

If anyone can confirm that this simple reversal is all that is needed then I'll go ahead and add the isolated studs and the extra cabling. If there is any doubt then I'll scrap the idea.

By buffalo (*)

Date 01-29-2003 00:54

I don't want to steer you wrong and screw up your machine, so get some more advice too, but I've been welding for 20 yrs and I've done nothing but switch wire. Polarity I don't think has anything to do with it. You may need to change your feed roller, to one with teeth designed to push soft flux cored wire and use a 75-25 mixture of gas. Good Luck!

- Buffalo

By pipewelder_1999 (****)

Date 01-29-2003 02:52

Most Gas Shielded Flux core wires run the same current and polarity as GMAW. IF you are speaking of self shielded flux cored wire such a E71T-11 then the polarity would be DCSP as opposed to that used for GMAW (DCRP). Self shielded wires E70T3,4 runs on DCRP.

The common wire for that type of machine is usually 71T11 or GS.

As far as swapping leads. Can't help you.

Have a nice day

Gerald Austin
Iuka Miss.

By Ian Taylor (*)

Date 01-29-2003 17:26

Thanks for the replies. I'm wanting to use "self shielded" flux cored wire so I don't have to lug my gas bottle around with me when I do stuff in the field (which is usually on thicker material than I weld in my garage).

I'll give Snap-On a call but as far as I can tell its just a case of swopping the cables. If anyone knows for definate then please let me know (I'm not going to do anything unless I get a definitive answer).

Regards
Ian

By Ian Taylor (*)

Date 01-30-2003 17:24

Gerald

Have I miss-read your mail - are you saying that there is a Self shielding wire type (E70T3,4) that uses the same polarity (DCRP) as for GMAW ?

Regards
Ian

By dee

Date 01-29-2003 04:29

ask Snap-On... they'll know how to reverse polarity on the machine
regards
d

By jwright650 (*****)

Date 01-29-2003 12:16

I'm not sure about your Snap-on machine, but the little Hobart 135's you open the side panel and switch the leads for polarity changes, the lugs are marked so even I can't screw it up.
John Wright

By Ian Taylor (*)

Date 01-29-2003 18:44

John

I was going to build in some lugs as you have described (and as per the "dual" machine (ie gas and no-gas) I was looking at in Harbour Freight). I'm assuming there is no feedback circuitry in these Migs which would not like a polarity change. Maybe an "electrics" person can advise.

By sparx

Date 02-03-2003 19:28

a welding mahcine doesn't care what polarity it is running- electricity will run from negative to positive regardless of which end you are "using" for the torch....you could go ahead and build a couple of lugs to change polarity and not have a problem.

By stever

Date 01-30-2003 18:40

If you run self shielded flux cored wire you will have to operate at a higher heat range to get the same results as when using the shielding gas.

E-xxT-1 through 6 are electrode positive.

E-xxT-7 through 11 are electrode negative.

E-xxT-1,2 & 5 require external shielding gas.