Flux Cores getting me down...

[apg1984]

I Usally run a millermatic 212 set up with .035 hard wire and a 75/25 argon co2 mix at work. Works great but every once in a while i'll have to run flux core because I'm outdoors. I reversed the polarity, put in knurled drive wheels and put in a fresh liner. Now comes my problems. 1 as I'm welding the wire will just stop feeding. usually with mig i just flick the lead and the wire will pop out. With FC the wire gets all rats nested inside the machine. I loosened the clamp on the wire and make sure I have a new tip but it still happens mid weld instantly. This happens once in a while running mig but with FC it's like every half hour. Any ideas would be greatly appreciated. My other issue is on thinner steel I'm getting holes in my welds. kind of like perosity i guess. When i run mig I can use the same tip all day, FC i'm using about ten.. Is this typical of FC?

[MMW]

I run a lot of flux core gasless wire known as innershield. Using .045 mainly Hobart 21B. I don't have that problem. I set the drive roll tension just enough so it doesn't slip when welding but if it gets stuck it will slip slightly instead of birdnesting. Very rarely does it get stuck. I assume you are using the same gun for both wires & you blow it out when switching? I keep my nozzle on for both types of wires. My gun is 15' with a .045 liner.

What size wire & settings are you running?

[aametalmaster]

I run a lot of flux core gasless wire known as innershield. Using .045 mainly Hobart 21B. I don't have that problem. I set the drive roll tension just enough so it doesn't slip when welding but if it gets stuck it will slip slightly instead of birdnesting. Very rarely does it get stuck. I assume you are using the same gun for both wires & you blow it out when switching? I keep my nozzle on for both types of wires. My gun is 15' with a .045 liner.

What size wire & settings are you running?

Are your drive wheels knurled? I think smooth would be better...Bob

[MMW]

Are your drive wheels knurled? I think smooth would be better...Bob

I use v-groove knurled drive rolls for all flux core (with or without gas). It lets you use less tension on the rolls so as to not crush the wire.

[aametalmaster]

I use v-groove knurled drive rolls for all flux core (with or without gas). It lets you use less tension on the rolls so as to not crush the wire.

Well today the shop electrician added a longer ground from the 8'3" one that came on the machine. So that let me push the welder back so the gun was straight and i had zero problems it ran like it should have...Bob

[apg1984]

I run a lot of flux core gasless wire known as innershield. Using .045 mainly Hobart 21B. I don't have that problem. I set the drive roll tension just enough so it doesn't slip when welding but if it gets stuck it will slip slightly instead of birdnesting. Very rarely does it get stuck. I assume you are using the same gun for both wires & you blow it out when switching? I keep my nozzle on for both types of wires. My gun is 15' with a .045 liner.

What size wire & settings are you running?

I'm running 035 with a 15' miller lead. Are you suggesting i use a 045 liner with the 035 wire? i have my clamp as loose as it will go thats why i just dont see how its rats nesting so quick... I put a brand new liner in it when i switched to the flux. do you think the knurled wheels are pushing the wire to aggrsively. when i run mig its like you said it will slip and not tangle. its so frustrating.

[aametalmaster]

Page 9 has different drive wheels for your machine. I am going to try the mix and match at work tomorrow...Bob
http://www.millerwelds.com/om/t232385e_pt_mil.pdf

[aametalmaster]

its so frustrating.

Yup i have a brand spanking new MM251 with a 15' gun and i hate it. If it was mine and not the companies i would trade the 15 footer in a minute. I weld in a small area and i can't always keep the lead straight...Bob

[MMW]

I'm running 035 with a 15' miller lead. Are you suggesting i use a 045 liner with the 035 wire? i have my clamp as loose as it will go thats why i just dont see how its rats nesting so quick... I put a brand new liner in it when i switched to the flux. do you think the knurled wheels are pushing the wire to aggrsively. when i run mig its like you said it will slip and not tangle. its so frustrating.

No not suggesting that at all. When I run .035 wire in my gun with the .045 liner I do have some problems. The .035 flux wire is not as strong as solid which is why it birdsnests. If you are welding say 1/8" & up material switch to .045. You would also need the correct size liner. In general terms with flux core you can step up a size over solid because there is less material since the wire is hollow. So if you would normally use .035 go to .045.

What happens is the wire sticks in the tip & the rolls keep pushing so it is birdsnest between the rolls & where it enters the gun. Make sure your wire guide, rolls etc. are all lined up correctly & the gun is as close to rolls as it can be. You can also try anti-spatter spray on your nozzle.

You also need the spacer to keep the roll of wire tight. It should be a spring but you can even use a pc. of pipe or pvc pipe cut to the right size.

[aametalmaster]

I wouldn't trade solid wire w gas for non gas flux core. I weld outside too and use cardboard shields and tarps to block the wind. I just don't like non gas flux. Thats just me prob and i am sure someone who likes it will chime in.
Now i run gas flux at work all day everyday and i use lots of tips and have birds nests about once a day but the biggest prob is the company bought aftermarket tip adaptors and they are just too long and i spend lots of time grinding dow 1/2 of a new tip. Think i will take some home and wack them off in my lathe and do a proper deburring of the end...Bob