Question about MM135

[Paul Seaman]

Normally Flux core runs straight polarity {opposite of the normal mig process}!

Check your book, but I am pretty certain!

[DDA52]

Great. Someone gave me a 2lb roll of .035 solid that I need to figger out how to use. I will be welding 3/8" mild plate (multipass), so I think I should slow the wire speed down a hair vs. the .030 and set the voltage to 10. MM135, 75/25 argon.

Am I right?

Karl

Karl, if you lower the WFS, the penetration will be less. Run it at 10/60, or 10/65. Play around with the feed speed. If it is too fast, you'll know it. The wire will stub the work. Too slow, and you will sacrifice penetration.

The MM 135 is a good light metal MIG, but it doesn't have the juevos to do "critical" welds in 3/8. If your weld is a critical one, you might consider another welder or have it done.....just a thought.

[DDA52]

Thanks for the replies. My next question for you MIG guys is I've been trying to do some lap welds with 1/8" plate to 1/8" plate (all mild steel) on the MM135. The quality of the welds has been hit or miss. Sometimes the weld holds up to the hammer test and sometimes I just get cold lapping. My technique is consistent on each try: I have the gun aimed straight at the bottom piece, initiate the puddle and then push it into the top piece. I use a push angle of about 15 degrees. I get good penetration into the top piece, but sometimes it cold laps the bottom piece. I'm using .030 solid wire, a voltage setting of 10 (max), and somewhere around 50 for wire feed speed. Any suggestions?

Thanks again.

You may need to bump your wire speed up. If you have the current model board, the settings should be 10/60. That will be in the ball park if you have good input voltage/amperage. Are you running the MM 135 on a 20 amp dedicated circuit, with nothing else on the plug?? If so, try the higher WFS, and fine tune it from there. Remember, WFS is what controls penetration. If you are too slow, the penetration won't be there.

You may want to aim the gun at the joint center or the "v". Make sure you maintain the stickout legnth. It should be about 1/4 to 1/2 inch for short circuiting mild steel. Joint design and different materials may indicate a longer stickout. If it is too long, it can result in too much weld metal being fed due to the welder increasing the WFS. I'm not sure if the MM 135 will do this or nor, but others will. Weld metal in excess of the voltage output will result in incomplete fusion at the toes and lack of penetration. The gun angle should be about ten degrees also.

Keep on practicing. If you can, post some pics of the beads. Pics can help us diagnose some of the problems. Besides that, we like pics!

[kdahm]

millermania,
The Millermatic 135 is able to weld with .035 solid wire but the weld performance is better with .030 solid wire and they both provide the same material thickness capabilities.

Kevin

Great. Someone gave me a 2lb roll of .035 solid that I need to figger out how to use. I will be welding 3/8" mild plate (multipass), so I think I should slow the wire speed down a hair vs. the .030 and set the voltage to 10. MM135, 75/25 argon.

Am I right?

Karl

[millermania]

Thanks for the replies. My next question for you MIG guys is I've been trying to do some lap welds with 1/8" plate to 1/8" plate (all mild steel) on the MM135. The quality of the welds has been hit or miss. Sometimes the weld holds up to the hammer test and sometimes I just get cold lapping. My technique is consistent on each try: I have the gun aimed straight at the bottom piece, initiate the puddle and then push it into the top piece. I use a push angle of about 15 degrees. I get good penetration into the top piece, but sometimes it cold laps the bottom piece. I'm using .030 solid wire, a voltage setting of 10 (max), and somewhere around 50 for wire feed speed. Any suggestions?

Thanks again.

[wrench3047]

cool, I guesstamated correcter.

[sparx]

The reason that you can burn a larger diameter fluxcored wire than solid, is that the f/c wire is tubular. the cross section of the wire shows that voltage required to burn the outer sheath of the f/c wire is much less than the solid wire, due to less metal being melted.

[Kevin]

millermania,
The Millermatic 135 is able to weld with .035 solid wire but the weld performance is better with .030 solid wire and they both provide the same material thickness capabilities. Using .035 flux cored wire requires an amperage similar to that of .030 solid wire so it also performs very well with the Millermatic 135.

Kevin

[wrench3047]

Not sure exactly, but I think it take a little less power to run flux core. Thus the little more dia flux core it can burn.

[millermania]

Is there a reason you can use .035 flux-cored, but not .035 solid-cored wire on the MM135?