Welding Tips and Tricks

I posted this on another forum, so I thought I'd post it here in case others need to reference it.

This is my method of Y-mixing together pure Argon and C25 to achieve my desired mixture of Cxx mixed gas that I need for spray and/or pulse spray MIG.

Here is my set-up for my C10 mix:



I use this Western valve, and other fittings that I purchased from my LWS, about $32 in it all:








Here are the formulas:

To know the mixture's Argon %:



To know the mixture's CO2 % (easier since it's only coming from one tank):



Formula notes:

• Ar_FlowRate is the flowrate coming from only the argon tank regulator/flowmeter.
• C25_FlowRate is the flowrate coming from only the C25 tank regulator/flowmeter.
• Total FlowRate is the combined (summed) flowrate as seen at the regulators/flowmeters on the Argon and C25 tanks (aka just add them together).

The question then becomes, what individual flowrates does one need to get in the ball-park for a typical C10 (90% Argon/10% CO2) mix?

Turns out, for a ~25 CFH final mix flowrate, a 15-16 CFH flowrate of Ar, and about 9 CFH of C25 will net approximately C10:

► Here is an online graphing calculator that I use, that has sliders to easily see mixture percentages◄




Tried it out with my HTP ProPulse 300 with full manual double-pulse settings, and it easily get MIG like TIG without dialing down the heat and worrying about cold-lap/lack of fusion. This double-pulse sprays HOT! Turned my aluminized backer pad on my guide hand to dust in one pass flat, lol.




This one I think I did with the ProPulse 200.



Anyhow, hopefully people find this useful.

Quite clearly that works, and you are a very smart person. Not in my league, that's for sure.

Thanks. We're all smart in our own ways. I just like to crunch numbers and work with equations.

Lucky you. My brain implodes at the mere notion of maths higher that elementary school. But luckily I can remember every single unpleasant thing that has ever happened to me. So that's a bonus. If I were to do a set up like yours, I think I would just gently fiddle with the dials until I got the desired result.

Best regards, mick

Oscar, thanks for the information and the time spent in the figuring. I am only wondering ... does one tank overcome the pressure of the other at any point in the use of the gases? OR is it possible to insert one way (anti back pressure) valves in the set up?

As long as both regulators are putting out the same pressure, likely about 50 psi. Then you wouldn’t need check valves until the tank pressure drops low enough to cause pressure variations on the output of the regulators. By the time that happens you are almost out of gas and in need of a tank change. Flow rates and tank size would increase the need to monitor tank pressure but that’s easy enough.

Poland308 wrote:As long as both regulators are putting out the same pressure, likely about 50 psi. Then you wouldn’t need check valves until the tank pressure drops low enough to cause pressure variations on the output of the regulators. By the time that happens you are almost out of gas and in need of a tank change. Flow rates and tank size would increase the need to monitor tank pressure but that’s easy enough.

Exactly, no need to worry about tank pressures because there are regulators installed that are usually/typically equalized in pressures.

Thank you for that information. I suppose I'm too far outside the box and worried about equalization. Being retired fly boy and using too much right aileron.

It’s a legitimate concern. Because not all regulators are set for the same pressure. Some of the fixed / non adjustable ones I’ve seen are set as low as 15 psi or as high as 75psi. If you miss matched then then it would definitely throw off the mix.

I'm actually considering installing some downstream regulators to drop down the pressure from 50psi down to 20-25psi, as I only use a 10-12ft mig whip. It would reduce the high-flow surge at the beginning and save gas in the long run when doing a lot of short beads/tacks. A couple of small 1/4" NPT regulators with low-scale should provide for better resolution of lower delivery pressures, and I'm going to possibly invest on some lower-scale argon/helium flowmeters from Dakota Instruments:

I'm totally doing this. I already have an argon and C25 tank. Plus since I was going to get a "y" adapter to connect both tanks to my MIG welder anyway why not try a little chemistry to see if I can get that thing to spray arc without out getting another tank?

Waggs63 wrote:I'm totally doing this. I already have an argon and C25 tank. Plus since I was going to get a "y" adapter to connect both tanks to my MIG welder anyway why not try a little chemistry to see if I can get that thing to spray arc without out getting another tank?

Glad I could help. Since then I have created my own gas mixing station for less than the thousands of dollars it would have cost me to get dedicated gas mixers. I've even created a spreadsheet that anyone can use (by downloading it) to calculate their own mixtures.

AMY0qnM3jdg


►Gas Mixing Google Sheet (can download as an Excel .xlxs)◄


Let me know if you need any help setting this up. Oh, word of advice, use teflon tape on all the threads, even though they are not pipe threads that seal. I had some imperfect fitting fittings, and it would bleed down on it's own (after I shut down the tanks) and not hold pressure. Some teflon tape and it sealed it all up perfectly. YMMV, so take my advice for what it's worth.

I remember sending you a PM about this a while back, how would you go about creating an Argon/O2 mix seeing as argon regulator's typically read CFH and O2 regulators read PSI? Seeing as I actually have an O2 and pure argon tank now It has me curious.

sbaker56 wrote:I remember sending you a PM about this a while back, how would you go about creating an Argon/O2 mix seeing as argon regulator's typically read CFH and O2 regulators read PSI? Seeing as I actually have an O2 and pure argon tank now It has me curious.

The way you do it is like how I did it, shown in the video. Using an O2 flowmeter being fed from the oxygen regulator, which would be set at 50psi. Then just add one of those Dakota flowmeters so you can precisely regulate low flow-rates of O2 into the mix. Keep in mind that using O2 does "dull" the bead, and it pretty much uses up all the deoxidizers in the filler metal, so your base metal has to be very clean. No millscale/rust/crud/etc.

Oscar wrote:

sbaker56 wrote:I remember sending you a PM about this a while back, how would you go about creating an Argon/O2 mix seeing as argon regulator's typically read CFH and O2 regulators read PSI? Seeing as I actually have an O2 and pure argon tank now It has me curious.

The way you do it is like how I did it, shown in the video. Using an O2 flowmeter being fed from the oxygen regulator, which would be set at 50psi. Then just add one of those Dakota flowmeters so you can precisely regulate low flow-rates of O2 into the mix. Keep in mind that using O2 does "dull" the bead, and it pretty much uses up all the deoxidizers in the filler metal, so your base metal has to be very clean. No millscale/rust/crud/etc.

Might be worth it spraying with a CC compatible suitcase and an ar/C02 mix than trying to get max heat out of my little 210 then.