Dual Shield? Metal Core?

[propanehotrod]

Hi
Right now Im stuck with a 200 amp machine (200powermig) I am needing a bit more power at times and was wondering about using a dual shield or metal core wire to compensate. I am currently running a 95/5 argon mix and understand I will have to change gas (Straight co2 ?) I checked the lws and they handed me an esab book with about 30 or more choices of dual shield. Hoping somebody can narrow it down a bit. I can run a .045 wire size.

[turk]

i use lincoln 71m dualshield .035 wire with 100% co2, and love it's deep penetration, and ease of use.

[4on12]

I like Hobart Excel arc 71 with 75/25 argon/CO2

[tackit]

First If you only need a "bit" more power maybe going to 75/25 would be all you need to do.

Then there is pre heating the steel with a torch if it's just to get by on this one job or it's not a large welding job and preheating doesn't break any rules.

How long is the power cord/extension cord you're using?

Is it's wire guage large enough to take care of any voltage drop if the cable is long?

If the power cable is wired directly to the cutout box you could turn off the power and retighten the wire lug screws.

[Scott Young]

I like esab 7100 ultra dual shield with C25 gas. For your machine I would try a spool of .035. It should work well within the specs of your machine.

If you are wanting more bite then I would use .035 hard wire with C25 or even straight CO2.

Tackit has a point on checking the wiring.

[propanehotrod]

Ok I should have said I need a LOT more power at times. I have been getting more and more big stuff to work on. Sometimes up to 2 inches thick. Its easy to go way beyond the duty cycle of my machine. Im shopping for a bigger machine but in the meantime I have to get this stuff done.
I have been pre-heating.
The wiring is in great shape and stays cool. No extension cords being used.
As far as gas, I thought 95/5 was hotter than 75/25?
I have heard of esab 7100 ultra...may give it a try.
Thanks for your help guys.

[Scott Young]

If your Big 40 has CV then buy a suitcase and run from it. You could also smaw it with your welder. depending on the position of the 2 inch weld your machine will burn up to 1/4 rods and yawn through most of it. you have 300 amps at 100% and 400 at 60% if my memory serves me right. If you want to burn wire and weld 2" all day then you will need a bigger machine. Too many people get into the habit of burning wire and forget the ole smaw sitting over in the corner. You also have the square wave that can run smaw.

For occasional 2 inch, I would run straight co2 or c25 and .035 esab 7100 ultra. Preheat your work (you should be doing that anyway) and weld away.

[propanehotrod]

yea I usuall run the square wave 275 when stuff gets too big for the powermig. Just looking to make the powermig a little more usefull. Got a buddy that use to go on and on about runnin dual shield.

[propanehotrod]

btw my big 40 is only CC and the guys at the lws look at you like you have 2 heads if you ask for 1/4" 7018

[turk]

what about a ln-25

[sn0border88]

Another thing to keep in mind is that metal core is for flat position only.

[ESABREP]

lots on things going on here. If you want to run a "dual shield" wire then go with .045 or .052. I like our 710X on 100% CO2. 250amps in any position. If you run .035 gas shielded flux core wire you are going to pay our the a$$ for it compared to .045. Also, if you plan on doing this you need around a 250-300amp machine. If you want, you can get a AVS feeder for your Miller CC machine and run it off of it. It is not to "code", but you can do it. Keppel Amfels in brownsville, tx runs SRH 444's with miller avs feeders all day everyday. Pretty much it will make the arc a little more sensitive to stick out flucuations. As far as the gas goes, unless the wire is made to run on higher argon, stick with a 75% max. The aws class will determine the wire. We have Dual Shield 70 Ultra Plus that can run up to 90% argon. Your mechanicals will change as your gas changes.

Metal core wire is great for low fume and high depositions, but has around the same usability as solid wire. Ie. you can short arc, spray and pulse with it, however to use in out of position you need to use pusle or short arc. Also, you will need at least 75/25 gas. I always run procedures with 90/10 or 92/8. Just my preference and it changes depending on the need for penetration or bead profile.

Overview. You need either a avs feeder and use your miller 40, or get another machine 300amp or 250amp. Hope it helps.

[Pro-Fab]

Originally Posted by propanehotrod

btw my big 40 is only CC and the guys at the lws look at you like you have 2 heads if you ask for 1/4" 7018

If you get a suitcase welder that is voltage sensing, you can run it off of a CC welder. The newer digital suitcase feeders can be set up a lot better than the older ones. I find that they perform real nice when running .045" flux cored wire. There are not too many burning 1/4" rod these days, but I am sure that they can bring it in for you.

[daddy]

Originally Posted by 4on12

I like Hobart Excel arc 71 with 75/25 argon/CO2

This is a very good wire.