Welding with flux core wire

[Chris A]

I'm using Lincoln NR211MP flux core wire and my welds are very porous. The welds look like I'm using solid wire and ran out of gas. Most of the bead has no slag covering it, only slag in patches. Anybody got any ideas or tips?
Thanks!

[Rambozo]

What are you welding and with what settings?

[performance]

What's the polarity you are using?

[TheGary]

Sounds like you need to change the polarity. flux core polarity is the opposite of hard wire. You should be running 18-19 volts and about 130 imp . That should put you at about 170 amps . If you are welding thinner metal go to about 16-17 volts and you wire speed should be around 100 i.m.p. Its like stick welding in slow motion you will have a lot of control over the weld. You will need to run multiple passes on anything thicker than 1/4 in. I am assuming you are running .045 if you are running smaller wire the settings will be a little different. You can google lincoln nr211 mp and it will have a table with the settings for the various sizes of wire.

[Chris A]

Thanks for the replies. Gary, I googled the wire type and found an instruction manual for using this type of wire. That helped a lot. It turns out I was using too much voltage and the welds look MUCH better after I turned the voltage down. The arc seems really short, but the welds look good, so I guess its the right setting.

[zoama]

Thanks for the replies. Gary, I googled the wire type and found an instruction manual for using this type of wire. That helped a lot. It turns out I was using too much voltage and the welds look MUCH better after I turned the voltage down. The arc seems really short, but the welds look good, so I guess its the right setting.

What polarity are you using ?

[Chris A]

My gun is hooked to negative.