what the sam hill ???

[tackit]

I am just starting to spray arc so I'm trying to read all I can about the spray transfer method. I got to Ed Craig's Welding Reality site now I'm more confused than helped, I guess it's to much information for me to grasp at one reading.

One thing he' says is that when making welds >3/16 over mill scale, any mixture containing oxygen is bad because the oxygen will produce porosity (oxidization) and a low strength weld. He went on to say a mixture of argon and 10-20 % CO2 is the best mixture when using the spray transfer method on the above. I'm guessing this does not pertain to clean steel. What do you guys think?

What than, is 98/2 good for. I was hoping to spray 3/4"-1" long welds on clean 1 1/2" X .125 mild steel sq.tube with 035 wire. Will 98/2 be to hot?... Should I stay with short circuit?... What volts and wire speed should I start with using the 98/2 for spraying 1/8 tubing?

And now I forget what the **** the 2% is, is it oxygen or CO2, I was thinking it was oxygen right?

Thanks for any help putting me straight guys.

[Alex]

tackit,
Personally, I've never seen a 98/2 Ar/CO2 mix anywhere. 95/5 is the lowest CO2 percentage I know of. However, 98/2 Ar/O2 is pretty common. Be advised that when using any O2 mix, the arc is going to be hotter and brighter than with a CO2 mix.

Y'all be cool,
Alex

[tackit]

Thanks Alex, I appreciate your input,at least one question is answered, I feel better already.

[Teeps]

98/2 C02 is used for stainless
Especially the thin stuff.

Otherwise tri-mix is best.

errr, I'm thinking short-circuit though, not sure if that differs on spray-transfer.

[joebass]

I have never heard of 98/2 CO2, but you can spray stainless with 98/2 AR/O2. You can also spray mild steel with it or use 90/10 CO2 or 92/8 CO2. I have only used 98/2 AR/O2 to spray, I use C-25 for short arc, and Tri-mix for stainless. Maybe Hawk, Andy, or Dan or somebody else could chime in and tell the differences in the other spray gases.

[tackit]

Sorry guys, I did a search and found all my answers, I am ashamed, I was so confused from all the reading I didn't even think about search, lesson learned, from now on I will go to search first.

http://www.millermotorsports.com/mboard/search.php?searchid=5234

[dyn88]

not to be off subject but stainless should be welded with-90he/8ar/2co2. this works very well as i just found out yesterday and it is what miller recomends!

[paulrbrown]

"not to be off subject but stainless should be welded with-90he/8ar/2co2. this works very well as i just found out yesterday and it is what miller recomends!"

dyn88, but not if you are spray arcing, Miller also recommends that for spray arcing stainless, AR98%/02% is what you need, you need a high percentage of argon to get the spray transfer. Note, you probably don't want to use spray arc on thin material, as it is hot,hot,hot.....but for 3/16 and above, it makes for short work,smooth beads, and better penetration, and it sounds great....
Hope this is clear, Paul

[HAWK]

Paul,

I had a 2 year contract involving 1/16", 1/8" and 1/4" mild steel. I ran spray arc on all. Granted a non pulsed spray gets wicked in 1/16", but should not be a problem for 1/8" mild steel. I ran a 92%Ar/8%CO2 for shield. I did find the 98%Ar/2%O2 too hot for 1/8" and down.

[cope]

Paul,

I had a 2 year contract involving 1/16", 1/8" and 1/4" mild steel. I ran spray arc on all. Granted a non pulsed spray gets wicked in 1/16", but should not be a problem for 1/8" mild steel. I ran a 92%Ar/8%CO2 for shield. I did find the 98%Ar/2%O2 too hot for 1/8" and down.

Hawk,

Please tell me which brand and model glove you prefer for Mig. I am using a heavy duty generic leather work glove now but I would prefer a good Mig type glove.

[paulrbrown]

cope, I like the Tillman 750 ,it is unlined Elk skin, which shrinks less than cow when exposed to heat. The amp ranges I usually are in are 110 to 180 short circuit. For lots of Spray, it can get hot, so you mignt want to get an aluminum reflector for your non trigger hand. These look like big and clumsey gloves, but are quite supple, they work great for lower amperage SMAW below 200, also. Hope this helps, Paul

[paulrbrown]

Hawk, I spray arced for over a year every day on 1/8 sheet to 3/16 angle A36 steel with 95ar/5o2 and it was great, it saved at least 75% in time, and no splatter to clean, pluse the welds looked like a bead of toothpaste, never any doubt about the integrety of the weld. And you never had anyone hanging over your shoulder watching because of the brightness. Paul

[cope]

cope, I like the Tillman 750 ,it is unlined Elk skin, which shrinks less than cow when exposed to heat. The amp ranges I usually are in are 110 to 180 short circuit. For lots of Spray, it can get hot, so you mignt want to get an aluminum reflector for your non trigger hand. These look like big and clumsey gloves, but are quite supple, they work great for lower amperage SMAW below 200, also. Hope this helps, Paul

PAul,

That's the range I will be in also. Thanks for the information.