Welding Tips and Tricks

Hi,
So been having issues with feeding .035 steel wire in the powermig 300 and magnum 300 gun

This welder always use to be used for aluminum with the push pull gun by my dad for his aluminum fab business.
He doesn't do that anymore so the welder is just used periodically. It doesn't want to feed nice, It will burnback, sputter etc. Changed tips no change. We did have some wire that was slightly rusty so switched that out and put a new liner and trimmed to length.. The wire is undercoated and is old sitting in the shop but was sealed and no rust on it.

Checked everything over many times but can't seem to find anything.. I'm thinking grab a new roll of copper coated wire and maybe it's just this old wire even though this roll is clean to they eye..
Drive rollers don't have much use and I cleaned them up once with some fine emery paper and no difference.
It's a 15 foot magnum 300 gun.

Just looking for some more suggestions

did you change the rollers to the steel wire rollers?

Agree on checking drive rollers - aluminum rollers are U shape - steel are V shape - might be a long shot but if the machine is not in regular use have you checked spool tension brake ! one of my bigger machines this has a steel disc brake that rusts & causes problems from irregular tension - also I've had the wire speed pot get dirty & give irregular resistance leading to erratic wire speeds - usually a spray with contact cleaner from the board side & a few swift turns cures it.

By coated wire do you mean it has a black rubbery coating on the outside? If so it’s probably a outer shield wire. Depending on the actual kind of wire, it can be finicky. Get a picture of the label on the wire box. You may need to use oversized rollers and tips.

I run the wire into the table or glove to apply some resistance and tighten the roller until it does not slip. Try different positions with the gun without grounding! You should get a nice even feed. Then i make sure my wire feed speed is right for voltage.


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So I meant to say it's uncoated wire/bare steel.
Cleaning the drive rolls now, I think they've got some rust/dust build up from the previous roll of dirty wire.
I'm probably just going to buy a 8 inch / 12.5 pound spool of new copper coat er70-s6 and eliminate that factor. This wire is quite a number of years old it looks clean but maybe just has a very small amount of rust enough to screw things up and slip

When the wire goes through the feed rollers, right where it goes into the liner I've seen that get clogged and packed full of dirt and dust. Especially if you dont draw the wire through a cleaning pad before it goes into the rollers.

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If the old wire messed up the rollers or the tips then the liner is probably plugged. You might be able to pull it out and clean it butt usually you just replace that too

I switched liners after the bad wire. I then ran some other old wire that wasn't rusty but still feeding not the best. I picked up a 12 pound roll of L56 .035 and tried it today.. Seems better now. I am welding with straight co2 so a bit harder to dial it in perfectly.
I have heard of running 1 roll for cored wire (knurled) and 1 v Groove to help feed but doesn't seem right that I should have to do that. Maybe if I have issues again thats is what's needed?

It definitely seems better now but haven't used it enough to say its perfect.

Switching rollers depending on wire is normal. Some people even use a combination of flat and v grove at the same time.

Edit
V grove and knurled rollers are also size specific. ie one set of rollers usually only covers one wire size or a small range of wire sizes. I’ve even seen double grooved rollers that were one wire size on one side and when you flip them over there a different wire size.

Yeah I have the proper size rollers. .035. I really don't switch wire size. I have a set of .045 too but don't need the larger wire.
I'm not a total novice when It comes to welding, But mostly do stick welding. If I encounter more issues with the feeding I'm thinking next it'll be new rollers.
And thanks to everyone for replying

Drive rolls much match wire size and type. Gun liner must be clean and atleast the wire size or larger. Contact tip in the gun should match the wire size.
Next thing to check is drive roller tension. Aluminum wire can be ran with less tension than steel wire.
Make sure the run in feature is turned off. Same goes for spot weld feature (if the machine has these features).

Yep All of that is correct. It seems better now with new wire, time will tell if it stays that way.
Even when I changed out the liner the old one didn't seem dirty when I blew it out nothing came out, but replaced it anyway.

Gun liners are inexpensive. I usually go with a 1/16 size liner. I push 035 and 045 wire through it.

Well it seems better now, With new wire cleaned drive rollers and the liner is pretty much too as well.

I find it slips when the tension is in the lower half of the adjustment, crank it down more and it's fine.. I have been hesitant on tightening it too much for the extra stress on the motor but the machine will code out it it draws too much amperage for the drive motor. I'm going to run it like this now and see how it does for a while.

Thanks everyone!