View Full Version : Flux core wire sizing

11-29-2015, 04:51 PM
I am looking at getting some nr-212 or Fabshield 21-B to run through my LN-25 powered by a trailblazer 302 for mobile repairs.

The smallest material I envision welding would be 1/4" but most will be 1/2" to 3/4".

Wire size choices are .045, .068 and 5/64 (.078).

I know I will have to get the appropriate gun and drive rolls.

Which would serve me best? Seems the bigger wires would be nice for welding the thicker metal but I am not sure how many amps that takes and if the 302 is up to something like 5/64. Also I wonder how the larger wires will do on the ocassional 1/4" welding I do.

11-29-2015, 05:05 PM
I would use .068. I think you will be at or close to max output to run the larger wire.

11-29-2015, 05:15 PM
I would get both .045“, and 1/16“ or .068“. Lincoln’s NR-212 doesn’t come in 1/16“.

11-29-2015, 08:08 PM
I am running hobart 21b .045 with my trailblazer. It runs well but is not big enough to run real heavy plate with any efficiency. I would use .045 with anything 3/8 or less and run .062 for the heavy plate. I will say that I like the way the lincoln nr211mp runs better than I like the hobart 21B. If you look at your specs on the trailblazer 302 it will go to 325 amps in mig mode so you have plenty of power there for .068 . I would find out what the LWS in your area carry. I had to special order the hobart 21b and I hade to take a case of 4 10lb rolls. The lincoln wires seem to be more readily available . If you plan to run a lot of flux core get a gun just for flux core. My Bernard 300 gas gun runs the .045 but I have to be careful to keep it fairly straight. Anything larger than .045 I would use only in a flux core gun.

11-29-2015, 08:14 PM
Here is some .045" Hobart 21B I ran with my brother-n-law’s Everlast PowerArc 200ST.

11-29-2015, 08:25 PM
Here is some .045" Hobart 21B I ran with my brother-n-law’s Everlast PowerArc 200ST.

Those are some nice looking welds for being done with a CC welder.

11-29-2015, 08:35 PM
Thank you!;) Trust me, it’s all in the wire, and welder. I’m just a hobbyist welder! :o:o

11-30-2015, 03:31 AM
being you said "repairs", i'd want some .045 cracks/gaps usaully aren't nice, and i get easily overwhelmed w/ heavy filler. i kinda think tieing stringers together is best for stuff like that. you'll see. you might end up favoring stick for stuff like that.

11-30-2015, 03:35 AM
Thanks guys. Going to buy a roll of .045 and see how if feeds through my mig gun. If it feeds and I like how it welds I may just stick with that but if I want more then I will pony up for some .068 and a flux core gun.

11-30-2015, 07:35 AM
If the liner in your Mig gun is big enough, you might be OK running .045" self shielded wire through it. Remember to keep the gun as straight as possible when welding. And you might want to put the gas nozzle away when welding, it will fill up with splatter.