Thinking about a Miller 12VS Suitcase MIG unit...

[ThomasH]

That's why I asked, I saw the 12VS demod before I bought it and the welds looked just like the lighter MIG welder that I have (200 amp/35%) with .035 wire (I don't know what it was other than it was lincoln wire) welding some 1/4" steel. A bad liner is the same as any MIG unit, they are using TWECO 400 amp MIG guns (which I was going to swap for a TWECO 250 amp gun for lighter outside work). As far as porosity, the only time I have experienced that was when the welding area wasn't shielded from wind gusts well enough. I have seen welds that were done by others where the steel wasn't cleaned well, and the welds looked like crap, and I went over them with SMAW rods to make the welds safe.

Ok, it sounds like it's the same set of issues as any MIG unit to me, unless I am not understanding something.

Tom

 

[Shield Arc]

If you're going to weld outside much, I'd get a Lincoln K-126 flux core gun with the Miller adapter. And if you're not going to do any seismic code work like FEMA 353, where you can avoid T-8 wires. I'd go with Hobart's Fabshield 21-B. I can't tell you how many 1-inch V-butt side bend tests I passed with that wire. Very good general purpose wire. :thumbsup:

 

[ThomasH]

I went to Hobart's site and looked at fabshield 21-B, and it looks like standard flux-core .035 wire. So I guess my MIG ignorance is showing, I haven't used that wire before, and all of the MIG work that I have done was on 1/4" and smaller steel with my Hobart Handler 200, and it was ok. What got me moving in the direction of having a heavy duty MIG setup was that I do repairs sometimes on wheel loader buckets and such, with typically 3/8 - 3/4 steel (most is 1/2 or 5/8) and have always stick welded it with 7018 except for root passes of some joints, which was 6010. So the welds were pretty good with reasonably good appearance, good penetration, and very strong.

Then I worked a few hours with a guy doing a repair on a 3/4" bucket with a XMT304 and wire feed with Lincoln Dual-Shield .045 wire, and it lays down very quick, has good penetration, and really fast build. He had the welder cranked up to 275 amps when he was doing it and it was a really hot arc. It impressed me with the quality of the weld, the appearance and penetration were good, and the speed at which it was done was very fast. Lots faster than my stick welding.

So that's why I was thinking that I would use the Lincoln dual-shield wire. Do I assume correctly that you would need to do more grinding/beveling to use the lower amperage range of smaller wire such as Hobart 21-B? Just wondering...

Tom

 

[Shield Arc]

If you're going to do a steady diet of commercial loader buckets, remember a lot of them will have good percentage of manganeses in the steel. I would think you would be OK with most dual shield wires. Far as gasless flux core the last time I welded cutting edges on some huge shovels my company had in their rock yard I used Lincoln's NR-203 nickel.
Good joint prep is always the key to good welds. I've never used .035 flux core, smallest is .045. I don't think they make a dual shield wire that will run on a CC only machines! I'm sure you'll need a CV machine. Just about all T-8 wires require CV. The picture I posted of the 21-B was ran with a 48-year old CC engine drive. So make sure your power source has CV!

 

[ThomasH]

Yes, I have a Miller XMT304, which is CC/CV, TIG, stick, and either pulsed/non-pulsed at 300 amps. It is DC only, so no aluminum welding but other than that, it does most stuff really well.

Agreed, if it is not really clean, I will stick weld it. Some of the repair work that I end up doing is cut out / clean up the remainder of the joint area / cut out a replacement piece / weld it in. So if the clean up is doing well, MIG is in play, hence my wanting to try out Lincoln dual-shield. I really was impressed with what I saw when I saw it being used for a couple of hours. No porosity, good penetration, really good looking welds.

Unfortunately, better looking than mine... <grin>


Tom

 

[Arc weld]

Although it doesn't meet low temp. impact requirements, E70T-4 Self shielded Flux-Core (Lincoln NS3M) is used on buckets if you want high production welds in the flat and horizontal position. It's supposed to resist hydrogen cracking. If you get into the T8 and nickel self shielded wires, the cost goes way up. I've used some 3/32" NS3M and as long as it's running properly leaves a bead that looks like sub-arc! Went through a 50lb. roll in under 2 1/2 hours. I wouldn't recommend the 21B for buckets but NR 232 might be a good choice. If you can get out of the wind Dual-Shield wires generally have better mechanical properties than the self shielded flux-core wires and are cheaper. Keep in mind you have to add the shielding gas cost. There is a much wider variety of dual-shield wires available for just about every application.

NS3M
AWS: E70T-4
Top Features
Very high deposition rates
Increased resistance to hydrogen cracking and porosity
Soft, low penetrating arc for minimal base material admixture
Typical Applications
Open groove welds
Machinery bases and heavy equipment repair
Installing wear plates
6.4 - 12.7 mm (1/4 - 1/2 in) single pass fillet and lap welds
Welding Positions
Flat and horizontal

 

[Shield Arc]

Also remember Tom majority of dual shield wires are voltage sensitive, if the manufacture says 3/4-inch stick out, they are not kidding, do it! Another thing, dual shield wire will pick up moisture just like 7018, so store your wire in the plastic bag and in a warm place. If it does pickup moisture you can bake it in an oven just like 7018.
Dual shield can give you worm tracks, either by to much voltage, or moisture in the wire.

ESAB has a good article on worm tracks.
Worm Tracks - Causes and Cures

 

[Cat_Driver]

I just bought this: Multimatic™ 200
Multimatic 200 - Multiprocess Welder - Portable Welder - Miller Welding

I never welded in my life, five minutes after opening the box I was welding Aluminum using the Spoolmate. For what I was quoted for the job by local welders, I purchased all the equipment I needed and did the job myself AND STILL it was cheaper than having it done by a welder. So I got all my welding equipment for free doe my next project.

First weld looked horrible, but after an hour or so the brads were strong and pretty - again not one lesson from anyone, just watching a lot of you tube.

I'm a huge Aluminum fan, and this thing will blow through 1/8" Aluminum which is all I use.

It weighs almost nothing and can be used either 115 or 220 Volts.

 

[ThomasH]

Thanks to both ShieldArc and ArcWeld!!

It looks like I need to do some more reading before I buy a 44 pound spool and get going with the same stuff that I saw used. What he was using was Lincoln OuterSheild 71M .045 at 225 amps / 26 volts / DCEP / 250 inches minute with CO2. He was using 3/4 stick out, which is way more than I have used for ordinary gas shielded wire. It ran *really* hot, he had a reflective glove on to keep his hand from getting too hot. I asked him what a spool of wire cost, and he said it was about $90, which really isn't bad.

It cooled for 10 seconds, and then almost all of the slag fell off (verticle up) without even chipping. The weld looked great, with deep penetration on welding 1/2 steel to 3/4" steel. To add insult to injury, he was probably 3x the speed I was using my typical stick setup. He said he burned about 6 pounds an hour, and could go through the whole spool in a day. That's pretty fast to me, I don't use more than 5-7 pounds of sticks in a long day.

Tom

 

[Shield Arc]

I really like running dual shield, I always thought it was very fast. Here is an over head weld, and a vertical up I made with ESAB's 710X dual shield.