Advice neded- pulsed MIG opinion - millermatic 350P?

More question: miller states with pulsed mig use 90/10 argon co2 mix . Can I still use up my two almost full cylinder 75/25 argon co2 mix with pulsed mig?

In the shipyard where I work, we use Lincoln invertec 350 power sources with LN-15 and LN-25 machines, connected by "brain" cable and welding power lead.

We use 95/5 argon/CO2 mix for OS, HS, HSLA and HY steels.

I had a learning curve with getting used to pulse, but after the last four and a half months of pulsing in every position on thick and thin steels, I can tell you that you will still have some spatter, but so long as you are not welding in funky positions, or welding dirty steel, you should have pretty good results.

It is definitely cleaner than stick or inner-shield, often cleaner than dual shield (spatter wise) though you will have occasional porosity issues (just like any gas shielded process, it is very susceptible to contaminants or loss of shielding.)

Prolly not. If you are trying to get away from spatter, that is not the direction you want to go.

95/5 Argon/CO2 mix is probably the best for both traits- penetration and spatter reduction.

I love Blue (Miller) machines, but I think Lincoln has the edge in MIG pulsing right now. BTW Lincoln and Miller 350's are both Inverter machines.

The pulse will reduce your spatter, but not eliminate it. A lot of shops have gone to small dual-shield for stuff like that because it reduces spatter so much. I have had excellent luck running 0.035" ESAB 7100 ultra for architectural steel 3/16" to 3/8" thick. The 75/25 mix will work, but when it is used up switch to 80/20 or

90/10.

Hi all

He says 1/8th to 1/4 inch (3mm to 6mm). If on-the-flat, would that spray in? That gives no spatter, is fast, smooth and plenty of fusion. Suspect the answer is going to be he'd get the 1/4in but not the

1/8th in. ...? And isn't going to work positionally. Spray you only need a plain classic MIG though with 240A delivery at good duty cycle - and a robust torch

Richard S

Thank you all for the replies. Standard mig would not work (if I want spray transfer)because the plates are too thin to spray which requires high amps with standard MIG. all welds are flat horizantal position, max thickness is 1/4" but never 1/4" to 1/4" . 1/4" gets welded to thinner pieces sometime thins as a 1/16", 1/8,

3/16, 1/8" to C channel and so on. Our standard millermatic 210 did a fine job , but we weld a day and we clean the pices afterward ( half a day) of all spatter. Sometime with the edge of a large metal file (millbastard), air chissel needed on some other stuff in corners (speed), and we grind some as well. It must be smooth. I will spend the money to get a spay/ pulsed mig just to reduce the manual labor and reduce the pain in my wrist/joints after all the spatter removal. It is worth it to me. I am not as young as I used to be. With the pulsed Mig I can still get spay on thin stuff by rasing peak and lowering background voltage or %. I've worked with my advanced squarewave TIG on stainless , I can figure out the pulsed set up (I hope).

Ernie, the Esab 7100 sounds good but .045 would be too large for the small stuff, and .035 is rare and much more expensive. will have to deal with slag afterwards?

Thanks guys

questions and answers wrote in sci.engr.joining.welding on Mon, 11 Apr 2011 09:31:43 -0500:

Are each of these one off pieces, or is this several parts all the same.

If the latter, could you get some copper sheet and make some shields to protect the areas outside of the weld bead?

Well Folks I got one, Miller 350P.

My first impression: What a difference! Most if not all that was stated by Miller's brochure is true.

My spatter problem is solved. My old MM 210 did produce spatter free( read little spatter) welds in the low to about 120 amp range but anything higher with short arc meant globs of metal flying.

The new MM350P produce small amount of spatter on initial wire contact but once spay transfer starts spatter is almost nonexistent, even on hot rolled mill scale covered plates.

Being able to see the arc and the melting puddle is TIG like. I can see the arc gouging in on T welds filler flowing in and wetting in nice.

Arc length and cone size can be easily adjusted, this helps with undercuts.

75/25 gas works but produce a bit more spatter, but still less than with short arc.

Pros and cons:

Con: money in my bank account is less ( much less) after the purchase. Had to rent an other cylinder 90/10 gas. The stock mig gun that comes with it -Bernard Q300 - is gigantic, heavy, too big for small shop use. I have to buy an M25. (selling the Bernard).

Pros: Much less fumes produced, and less fumes go into my lungs. Spatter is almost all gone. Whatever is thrown easily clean up with the edge of the file. Now I can put away my air chisel. Tack welds on heavier plates actually hold. Weld beads aesthetically pleasing.

money I can save on: less holes in my welding shirt and pants, fewer replacement clear shield needed for my welding helmet. less welding wire being wasted as globs of metal on the floor. Less time wasted cleaning /grinding spatter or bead imperfections.

I should have got one 10 years ago. :)