spray transfer???

[mikesparks]

:every mig that i have used was short circuit trans but how do you achieve spray??? is it a different welder or a tecnique? im lost

[FM117]

I see you have a MM251....
Get some .035 wire, go get a small bottle of 90/10 gas,
crank up the voltage to somewhere north of 25-26 volts,
and finally set the wire speed to about 550-600 ipm.
Get a couple hunks of steel about 1/4 to 3/8 thick and
set em up for a fillet weld.
Aim the gun and pull the trigger...you will be spraying!
I'm a lazy type, so google a few descriptions of the
technical aspects regarding gases,and the voltages
and amps needed to transition the various sized wires.
Dave
Edit...crank up the gas flow to maybe 35-40cfh also

[mikesparks]

I see you have a MM251....
Get some .035 wire, go get a small bottle of 90/10 gas,
crank up the voltage to somewhere north of 25-26 volts,
and finally set the wire speed to about 550-600 ipm.
Get a couple hunks of steel about 1/4 to 3/8 thick and
set em up for a fillet weld.
Aim the gun and pull the trigger...you will be spraying!
I'm a lazy type, so google a few descriptions of the
technical aspects regarding gases,and the voltages
and amps needed to transition the various sized wires.
Dave
Edit...crank up the gas flow to maybe 35-40cfh also

im running .035 now but why cant you use 75/25 or 100% argon?

[FM117]

Can't tell you the exact reasons on the gas mixes.
You need at least 80% argon, never tried straight
argon?
There are other common spray mixes using 95-98 percent argon
and the balance is O2. The reason I like the 90/10 is it
also short-arcs well and I don't have to switch bottles around as
much.
Dave P.

[mikesparks]

Can't tell you the exact reasons on the gas mixes.
You need at least 80% argon, never tried straight
argon?
There are other common spray mixes using 95-98 percent argon
and the balance is O2. The reason I like the 90/10 is it
also short-arcs well and I don't have to switch bottles around as
much.
Dave P.

oh i will look into that

[hankj]

Spray arc requires an argon rich gas, but mild steel and 100% argon are not the best MIG mix. You can spray with pure argon, but a little CO² helps smooth out the arc very much. Argon with 2% to 10% CO² will give you good results.

Spray transfer occurs at high current and voltage. The numbers that FM117 provided should work. If it won't go into spray, crank up the wire feed a bit. Hold about a 3/4" (yeah, long is right) stickout. Travel speed is about twice as fast as short-arc. It sounds like escaping air - a nice hiss! I never turn up the shielding gas. Had good luck just leaving it at 20-CFH.

Hank