FCAW/Metal Core Question

I tried the Twenty Gauge .030 Metal Core wire by Harris, as recommended by Ernie. It's a gas shielded wire with flux in the metal core. It's primarily
designed to reduce burn through on thin sheet metal. However, the additional wetting and penetration due to the metal powder core and flux additives is very helpful, especially working outside with less than perfect metal prep and fit. Unfortunately, this is a single pass wire, only recommended up to 3/16" thickness. I've been looking into .035 low alloy metal core wires for fabrication. Looks like a good choice for all position welding with the large three phase box at work, which will have no problem supplying 200 amps or more as needed. What I'm wondering is if an .035 metal core wire will work at a lower amperage with a 230V welder such as a Hobart Handler 175. The lowest suggested amperage I've seen on manufacturer's websites is 135 amps,which I think is at the very top of what the Handler can provide. The wire is not available in small rolls for little machines, 33 pound steel wire coils is the smallest offered. That can be overcome by transferring the wire to a smaller coil, but will the wire work well at lower settings? Is there any reason it can't perform like .035 solid wire but with some additional shielding/penetration? Tech support at a couple manufacturers was reluctant to stray from the specific recommended applications. This seems like a natural application for metal core wire for multi-pass work with smaller machines. I hope we see more metal core offered in small rolls suitable for small 230V machines. In the meantime, does using .035 metal core low alloy at lower parameters sound feasible in a small machine?
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You are confusing terms. Flux core wire has a granular flux in its core. I comes in self shielding and gas shieldng varieties. Metal core is a completely different thing. Metal core has metal bits in its core and is much like solid wire. It is designed for very high deposition rates at very high amperages compared to other wires. Metal core wire is not a positional wire and generally intended for spray transfer at around 28+ volts. Smaller machines don't go there. It might be better to quote the AWS number for each wire you are describing. There is a reason we use AWS numbers for welding electrodes. Most 110 volt machines have a tough time handling wire .030 in diameter never mind .035 I can't understand why you thnk that a larger wire diameter would be better...... unless your wire feed rate is maxed out on the smaller wire? Randy

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Actually I think he was asking if you could run 0.035" metal core or dual shield wire in a 220 volt baby MIG like the Hobart Miller Lincoln 175's.
You would be really straining those machines to run that wire. And you would likely burn out the guns.
The machines one step up in the 200 amp range like the Miller 210 or Lincoln 200, should be able to handle it just fine.
Randy is right about flux-core wire and metal-core wire being 2 different creatures, but there is a flux in metal core wire, and they do have all position metal core wires now. They are just getting adopted in industry and are quickly eating into the gas shielded flux core (dual shield / outer shield) market.
I run 0.035" dual; shield wire all the time in my Betamig 250. The stuff works great on steel 3/16" to 3/8". For heavy H-beam work I use 0.045" dual shield, which maxes out my Betamig 250. I had to upgrade to a 400 amp Tregaskis toughgun to run the 0.045" dual shield for extended periods. It was melting down the Hobart (oxo) gun that came with my machine.

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Ernie, I have been running .035 dual shield with my Lincoln 175T and Co2 with it on the next to highest voltage selection and the wire speed about half way. If I change the voltage to the highest setting then it changes to spray mode. The wire is some Rockmount wire I got at Boeing surplus. Polaris Maximum Shield to be exact. The sheet in the box says Short Arc 20 to 28 volts 100 to 250 amps. Spray 28-32 volts 150 amps
My duty cycle is veny low as I am generally fitting stuff and not welding anything thicker than 3/16th inch. Dan
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Just be careful not to burn out your gun. Dual shield runs HOT in the gun nozzle.
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Running carbon dioxide allows you to use the rated amperage of your gun becaue it is such a cold gas coming out of the bottle. As soon as you use a mix you have to de-rate your gun. It is interesting that in spray mode the amperage is less. I guess there is a limit to the amount of power you can put through the wire. Randy
wrote:

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We run a fair amount of .052 71M at work, usually with 75/25 gas in all positions. I also do the ordering of supplies. Does the metal core wire deposit that much faster that any price increase could be justified? Do you know the price per pound off hand? Thanks Ernie!
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Not sure on pricing, but Metal Core wire is sweeping through industry. Much higher deposition rates and vert clean welds.
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wrote:

Yes.
Replacing the gun I think I could handle if I can obtain one second hand.
It would definitely be at the upper range of the machine's capacity, 175A at 30V, 30% duty cycle (and who knows how optimistic that is?)

ESAB has a whole range of metal core with additives. Some of the metal core has very low alloy content added and is designed for 75/25 or preferably 92/8. Coreweld 70 .035 looks like a potential candidate, with a 130 to 260 amp range.
" Description: Coreweld 70 is a tubular wire containing ingredients primarily comprised of metal powder along with additional arc stabilizers and alloying elements. The net result is a high efficiency (90 to 98%) wire.
Arc characteristics, weld metal transfer, spatter levels are improved, while silica islands are minimized with the use of Argon mixtures up to 92% Argon.
Due to the high level of iron powder and low slag components, the only slag formed by this wire are small islands of silica. This permits multiple pass welding welding without the need for deslagging the weld deposit between passes, while increasing productivity.
Coreweld 70 wires are available in 0.035" (0.9 mm) through 1/8" (3.2 mm) diameters. The small diameters up to 1/16" (1.6 mm) are capable of being welded out-of-position.
Coreweld 70 was designed for multipass welding in robotic applications where slag removal between passes is difficult. This metal cored product is intended for use on carbon steels having tensile strengths up to 70 ksi (483 MPa). "
Comes in ten pound rolls but not currently available for small orders.
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