[ntm]

I have a Syncrowave 210 which is a multiprocess machine with only a spool gun. Soon I'll be working on some fairly heavy weldments built up out of 1/4, 1/2, and 5/8 plate. I need a more productive welding method and I'm thinking dual-shield in spray- transfer mode. But I need a MIG machine.

I've heard that the MillerMatic 350P would fit the bill. But I wonder if there's another machine that would be good, something a little cheaper. I'm OK with it not lasting as long as one of the red or blue machines.

What "off-brand" welder do you recommend?

[Louie1961]

Millermatic 252 or 255 would fit the bill quite nicely. In the Lincoln lineup a promig 256, and in ESAB the rebel 285. The millermatic 255 is the nicest of the bunch however with pulse mig capabilities

[Louie1961]

Also, just so you know, gas shielded flux core (aka dual shield or outershield) isn't really run in spray mode, which is to say its not the same gas that you would use for actual spray transfer MIG (something like a 90/10 argon CO2 mix). Most dual shield wires will run on 75/25 or even straight CO2. I use Lincoln 71M quite a bit in my Millermatic 252, with straight CO2. Also you can weld with dual shield with less volts than are required for true spray arc welding. For spray transfer with a 90/10 gas mix, and 0.035 ER70-s6 wire, you need like 27-28 volts to hit spray transfer. With the 71M I would normally run 0.045 size wire at about 25 volts and 300-350 inches per minute, which is probably right around 220-240 amps.

There are also metal core wires that you can choose that are similar to dual shield, but might even be a little more productive. But you may want to go with a bigger machine for some of those.

[Oscar]

for 5/8" you need about 300A minimum with a good duty cycle. Once you're looking at machines in this range, they should have no trouble with gas-shielded flux core wire at those amperage levels.

[ntm]

Thanks for the input, guys. I ordered a Millermatic 255. Should be here this week.

I expect to mainly use spray and pulse-spray transfer mode but I may try other processes that need other gas ratios. I already have argon for TIG. If I get a bottle of CO2, how hard is it to mix 90/10 using the usual floating-ball type flow meters? Seems easy but maybe there's a catch...

[Oscar]

Thanks for the input, guys. I ordered a Millermatic 255. Should be here this week.

I expect to mainly use spray and pulse-spray transfer mode but I may try other processes that need other gas ratios. I already have argon for TIG. If I get a bottle of CO2, how hard is it to mix 90/10 using the usual floating-ball type flow meters? Seems easy but maybe there's a catch...

That's what I did initially when I started to use pulsed-spray, except I used an Argon tank and a C25 tank. Because the C25 tank already has the CO2 diluted, it's easier to meter out the needed amounts using a standard flowmeter. But with straight CO2, metering out precise amounts to achieve 90% Argon and 10% CO2 might be more difficult. For example, say you wanted 25 CFH of total shielding gas flow. You'd need 22.5 CFH Argon, and 2.5 CFH CO2. Think about how you will actually measure out 2.5 CFH of CO2. (hint: most flowmeters start at 10 CFH).

[Coldman]

If you have to get another cylinder of something anyway, why not a cylinder of 90/10? It's good for all mig work. C25 is better for short circuit on thick steel but I wouldn't recommend short circuit mig as a process on thick steel, especially with a 250 power source.