[daguirre79]

Hi, I have seen Jody using a Y connector to mix Argon and helium but, can I using the same method to mix Argon and co2 without using a expansive mixer? Also, what if was to use a Copper in line filter to help mix the gases as they run through the hose.

[Mike]

Welcome to the forum 79.

[Otto Nobedder]

Hi, I have seen Jody using a Y connector to mix Argon and helium but, can I using the same method to mix Argon and co2 without using a expansive mixer? Also, what if was to use a Copper in line filter to help mix the gases as they run through the hose.

Welcome!

Actually, mixing Ar and CO2 with a wye connector is easier than Ar/He. Why? Helium flow is hard to gauge accurately at the low flow rates used in TIG without a specialized flow-meter. The CO2 is much closer in density to argon, and getting a fairly accurate mix becomes simpler.

Adding an inline filter won't hurt, but moving gasses tend to mix very quickly due to turbulence in the hose, fittings, and torch lead.

Short-circuit MIG on carbon steel works with almost any combination from 100% CO2 to about 85% argon/15% CO2. Above that 85% you're looking at globular transfer and spray-arc.

Steve S

[daguirre79]

Otto,
Thanks for the reply, Would it be a waist of my time to try to get a 90% ar 10% co2 for spray transfer? Should I just get a mix bottle?

[Otto Nobedder]

If you already have the bottles and flow-meters, I'd sure try it. Spray transfer likes a lot of gas anyway, and it wouldn't be hard to get real close to 90/10. Setting flow at 45 Ar and 5 CO2 will get you started, then you can experiment with dialing them back a bit to save gas if needed. The few WPSs I've read on spray-arc call for 40-50 cfh, though, so that initial setting puts you in the ballpark.

Steve S

[soutthpaw]

Otto,
Thanks for the reply, Would it be a waist of my time to try to get a 90% ar 10% co2 for spray transfer? Should I just get a mix bottle?

This is what I keep in my 80cf mobile bottle. You might have to special order it depending on your LWS. But you can spray and short circuit with it.

[xryan]

I just keep a separate bottle full of 88/12 for spray pulse. No need to screw with 2 regulators.

Sent from my SCH-I605 using Tapatalk

[Otto Nobedder]

I suppose the question is;

Are you planning tons of spray-arc? In which case you should get a dedicated bottle. Do you have a small batch to do? In which case, already having the two bottles and appropriate flow-meters, mixing as you use it is perfectly fine. Are you simply wishing to experiment with spray-arc? This could go either way... A mix-gas bottle can be certified for the mix so you're confident of what you're welding with each time. If you're just wanting to examine the characteristics of spray, precision is less critical.

By the way, there's no reason to buy a wye fitting... A tee will do just fine, and even accelerate mixing as the two flows interfere with each other at the tee.

Steve S

[daguirre79]

This came up for a project, I am building some guard rail for a hospital and the project specifies D1.1 for all welding.
When writing the WPS I found Spray transfer is the only pre-qualified processes for GMAW and Lincoln L-56 Operating procure list 90% ar 10% Co2 for the process.
I do not have a bottle of 90/10 and did not want to get one just for this, so I thought I would make my own mix.
The tubing sizes are .188 wall and the pickets are 14GA. and 1/8" fillet.
I think this will go together just fine with Short Circuit but, depending on the deputy inspector I get I may have to use spray transfer.
I ended up getting a Y and all connecting parts for it, I was using it today and it worked well, I have a small bottle of 75/25, I did some welding with it then switch over to my blend with the two bottles and I was able to get what I thought was the same or similar result.
I may just get a bottle and have it on hand just in case I get a try hard inspector.

[Artie F. Emm]

I'd love to buy a co2 and mix my own co2-argon, if it could be done well, but I thought I had read that this type of mixing could not be done without expensive blending equipment. What's the true story?

[daguirre79]

Im sure the mixers are a lot more accurate than just adjusting two flow meters to get a blend of gas but, it seams to work well.
I dont think there is anything magical happening in the expansive mixer other than an accurate blend ratio but, Im no expert, Im looking for some information on it too.
Also, I do know when they fill the mix bottles they do not run the gases through a mixer they just fill the bottle to wherever the ration is 75/25, 90/10, one gas goes in first then the other, I got that from talking to a local suppler.

[Artie F. Emm]

Interesting idea, I may try transfilling from a co2 and then from an argon into an 80 cf cylinder. But it would have to be smart and safe.