How to spray with 350P?

TORQUIN · Jun 14, 2016

I have been reading several threads here regarding the 350P because I want to learn to use mine better. I'm OK with it. Never had a weld break, steel or aluminum, but would like to become better at it wherever possible. I use MIG almost exclusively because I do not understand the advantage to Pulse despite all I have read about it.
On the included charts with the 350P I see that in some places, for thicker steel it says "USE SPRAY" but the manual does not tell me how to set up the machine to "spray". Is this Pulse?

How is spray different from short-circuit? Seems like in all cases that filler wire is gonna have to touch the work to start the arc and then the arc will melt away the filler wire before it can touch the work again, so it's doing what in this scenario, spraying?

I am always open to Pulse, if someone can help me understand why it will be better.

Thanks,
Chris
Millermatic 350P
Synchrowave 351

Shield Arc · Jun 14, 2016

Here is a good read on spray arc welding.
Spray Arc

Stimw · Jun 14, 2016

I don't think my Miller 210 is supposed to spray but it will do something similar.
When I crank it up the wire transfers to the material in a melted form, spraying.
The big difference is in the sound. It goes quiet from the egg-frying sound to the electrical hum sound just like a TIG torch welding.
When it does this it lays a beautiful bead. (like TIG)
The MIG torch and nose cone get very hot too!
It puts out a lot more UV light so if you try it make sure you cover up exposed skin.

Arc weld · Jun 17, 2016

Spray and pulse are 2 different things. For true spray you need a higher concentration of argon/Co2 like 90% or better and you have to have the volts up around 26 or more. If you don't have the higher argon gas and just use C-25 you won't get spray but will get globular transfer. Spray is like it says, it sprays out the contact tip. The wire doesn't hit the puddle/base metal first like short circuit transfer.

TORQUIN · Jun 17, 2016

OK, but I guess my question is how is it set up? I just find it strange that the setup cards included in the welder give suggested setups for Pulse and most short, but in some places just say "Use Spray", which implies that I need to switch a setting someplace to "Spray". It gives no other info about spray usage/setup. This is the main reason I've never used it.
I have a small tank I could get the 90/10 mix in, but I don't know if I want to do that yet, as I'm not sure how to set it up. I have also read that it runs so hot that you can melt the tip of the gun. :hot: Just a little worried about that too.

Thanks,
Chris

Shield Arc · Jun 17, 2016

When I played with spray, I had to switch to my 400-amp Mig gun.
With spray you need really clean metal. At least 90/10 gas. And real high voltage.
This weld was done with .035" Lincoln L-56 Mig wire, and 90/10 gas. See how many volts?

Mark @ Everlast · Jun 17, 2016

Most of the technical information I find says 80/20 Ar/CO2 mix minimum. I personally use a mix from Air Gas that is their proprietary blend which they call C-18. It's 82/18. Works well for me. For heavy spray, I have used my ESAB MIG master 250 for 15 years this way. Can spray at the medium high setting with 60% wire feed speed...whatever that is. .035" wire.

BukitCase · Jun 17, 2016

Even though I don't have a 350P I got curious and downloaded the manual - even THAT doesn't say anything else about spray transfer, so I checked out miller's online mig calculator

MIG Solid-Core Welding Calculator - MillerWelds

For 1/8" and up, it lists both short circuit AND spray parameters...

After seeing/using the gun my mm252 came with, I wouldn't be surprised if that "oversight" is aimed toward NOT having to explain to customers why their mig gun melted

...Steve

Arc weld · Jun 17, 2016

Miller lists 98/2 for spray. I had a guy tell me that less than that you don't get a true spray transfer but a modified spray/globular transfer.

xryan · Jun 17, 2016

To use pulse mode in spray transfer you need 90/10 (ish) blend of gas, personally I usually use an 88/12 blend. DO NOT use 80/20 or 82/18 as stated above by Everlast and Airgas, pretty much all you need to know there...:thumbdown: For Spray transfer you need a higher percentage of argon and typically higher voltage then you would normally use in short circuit. Voltage is to electricity as pressure is to water, the voltage is what is pushing the puddle down into the base metal.

If you have only been using short circuit transfer with your 350P then honestly you have seriously overpaid and are not even beginning to use the full potential of the machine. Once you go pulse you'll never go back, seriously! Penetration almost like stick, smooth spatter free welds, what more could you ask for!

The "MIG" mode chart is telling you to use spray transfer for the thicker materials because spray has more penetration. As is often the case with unskilled weldors, they can lay down a "pretty" bead that is doing nothing more than sticking to the surface of the base metal and can easily be broken off. It's actually quite shocking to them when you show how poor their "weld" is when you hit it with a hammer and peel off their bead.

Arc weld · Jun 17, 2016

xryan said:
To use pulse mode in spray transfer you need 90/10 (ish) blend of gas, personally I usually use an 88/12 blend. DO NOT use 80/20 or 82/18 as stated above by Everlast and Airgas, pretty much all you need to know there...:thumbdown: For Spray transfer you need a higher percentage of argon and typically higher voltage then you would normally use in short circuit. Voltage is to electricity as pressure is to water, the voltage is what is pushing the puddle down into the base metal.

If you have only been using short circuit transfer with your 350P then honestly you have seriously overpaid and are not even beginning to use the full potential of the machine. Once you go pulse you'll never go back, seriously! Penetration almost like stick, smooth spatter free welds, what more could you ask for!

The "MIG" mode chart is telling you to use spray transfer for the thicker materials because spray has more penetration. As is often the case with unskilled weldors, they can lay down a "pretty" bead that is doing nothing more than sticking to the surface of the base metal and can easily be broken off. It's actually quite shocking to them when you show how poor their "weld" is when you hit it with a hammer and peel off their bead.

As a new member you're not off to a very good start. Spray transfer depends on more than volts and shielding gas mix. Wire size and amps play a role too. Sometimes globular transfer can be confused with spray. Here's a good article on MIG transfer modes and by golly 80/20 can spray at high amps.

Understanding transfer modes for GMAW - TheFabricator.com

Mysfyt · Jun 18, 2016

Last time I did spray transfer was back in the late 90's. I thought they had a couple percent oxygen in the mix. Whatever happened with that? Not an expert here, just asking.

Shield Arc · Jun 18, 2016

I wasn't all that impressed with spray. The metal has to be way to clean for me!:thumbdown:
I really liked metal core.

yomax4 · Jun 29, 2016

As long as you have Pulse, You don't need Spray. If you really want to try spray, Turn off the pulse, Set volts at about 23 and start a bead. Keep turning your wire speed down until you just get a hiss and a red hot flat no spatter weld. Argon 90 CO2 10 is the min. Like stated above, If you only have 75/25 you can still get the idea by turning up the volts while welding until you get the hiss or turning down the wire til you get the hiss. If Miller says 98/2 ( Argon/ Co2 ) that would be more of a Pulse Stainless mix. Lastly, The newer Digital High Def equipment from Europe can weld with Straight CO2 with No spatter and flat Spray / Pulse looking welds. They only use CO2 in Europe and they are wayyy ahead of the USA in the welding world. ( See Fronius, Lorch or OTC from Japan ) I like the Miller 350P machine ok but it's analog where the Lincoln equivalent is Digital. Not HD but close. Have fun with all the transfers and you will find uses for most of them.. It's all awesome.

BukitCase · Jun 29, 2016

Actually Miller's calculator recommends 98 Ar, 2% O2 -

MIG Solid-Core Welding Calculator - MillerWelds

Choose steel, 1/4" for an example... Steve

Mark @ Everlast · Jun 30, 2016

Yeah, Millers charts are known for being wrong...or lets just say what they want you to do so their equipment shines. Not necessarily what can be done, or is done.

TORQUIN · Jul 13, 2016

Thanks for all the opinions and info. I'm going to have to get a different mix to try this stuff out because when I tried spray with my 75/25 mix I got a lot of spatter. I do not know if this was because of the gas mix, but it is my prime suspect.
The only other gas I have right now is 100 Arg on the TIG.

Thanks,
Chris