Welding Tips and Tricks

If I have a cylinder of Argon and a cylinder of CO2 can I use the flow meters to mix them for MIG? e.g. 9 Ar + 1 CO2 = 10 mixed gas.

If I drill completely through a 1" block of metal then drill another hole perpendicular to the first but stop as soon as I hit the other hole, I form a T inside the block. On the leg of the T I put the output hose. On the remaining openings I connect the cylinders. The gases will be pointing at each other for mixing and then go out the exit to the welder. Would this work?

It might work as long as you have regulators on cylinders which will prevent back flow. You might consider another downstream mixing chamber like a capped piece of 3" pipe before sending the mix to the torch. This will break up any stratification that might be going on or maybe fit a swirl to the mix tube.


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I wondered about back flow. I have no idea if these regulators have back flow prevention, but common sense tells me they wouldn't. They are expecting flow only in one direction, so why engineer another 99.99999% useless valve into the device.

I suppose I could get some electronic valves and tap into the signal line of the welder to trigger them. It would then take 3 valves for flow to happen. Cumbersome but doable.

The main question still is would my idea actually work. Would the flow meters produce their gas streams in the ratios I'm expecting using my simple example? Would the 9 flow from the Argon cylinder overpower the 1 flow of CO2? I have to believe the need to mix gases as I've described - on the fly - has come up before. I'm wondering if anyone has experimented with this.

easiest and more common to use a Y connection that's backflow prevention built-in

I didn't know such a thing as you mention existed.

Can you list a source for where I could purchase a Y with back flow prevention? If this exists, then it exists for a reason - namely to mix gases from two sources. I can't think of any other possible reason and therefore my idea must have merit. A description of the device would possibly tell me if I'm correct.

Just Y them together. I use this setup all the time, works fine. Since the pressure from the regulators are so far below that of the tanks, I dont see how gas can back flow into a tank.
I use a valved Y after my argon flowmeter that I can choose to send argon straight to my tig, or turn that off and open the other valve to a Y to the hose from my Co2 flowmeter for mig. Or if I turn both off I have straight Co2.
I've been doing some spray transfer with my 8vs, and its a hoot. I just float the ball on the Co2 and run about 20-25 cfh argon.
There are several discussions on it on weldingweb. Irishfixit had a couple good ones.

Thanks for the mention for weldingweb.

What's an 8vs?

It's a suitcase welder from Miller

http://store.cyberweld.com/weingasyco.html

Poleframer wrote:Just Y them together. I use this setup all the time, works fine. Since the pressure from the regulators are so far below that of the tanks, I dont see how gas can back flow into a tank.
I use a valved Y after my argon flowmeter that I can choose to send argon straight to my tig, or turn that off and open the other valve to a Y to the hose from my Co2 flowmeter for mig. Or if I turn both off I have straight Co2.
I've been doing some spray transfer with my 8vs, and its a hoot. I just float the ball on the Co2 and run about 20-25 cfh argon.
There are several discussions on it on weldingweb. Irishfixit had a couple good ones.

That is good to read that you mix co2 and argon with success. I asked a similar question in France and was shown specific mixing equipment, very expensive, with I think a warmed chamber for the co2.

I need to look at the answers but I was told about specific problems when mixing directly from the bottles.

olek wrote:I need to look at the answers but I was told about specific problems when mixing directly from the bottles.

I use a premixed bottle which has its own potential problems. If left too long, the different gases will separate (stratify) within the bottle and change the gas mix coming out of the Regulator. So, it's either expensive or shelf life issues.

I would suppose inert gasses like argon and helium readily mix, people have been doing the Y connection for them for a long time, as does jody in one vid. Even argon Co2. I dont think an exact ratio is that important, to make C25 at exactly a 25-75 percent ratio is so important, if doing non code work is at hand. Anywhere from there to 50/50 works about the same.
I wouldnt venture to do a 98-2 percent argon oxy mix tho, or tri mix, I dont think you can get the pressures and flow rates that exacting.
For ME tho, only dealing with bottles of Co2 and argon for doing tig and mig, and being able to run an argon rich enough steel mix for spray transfer saves me from having to change regulators and bottles all around.
I'd sure like to know if there is a better Co2 regulator I can use, I dont need the high end of mine much, but under 5 cfh is just guesswork, one that would read down to 2 cfh would be handy.

I made a simple manifold of fittings, a tee, two valves and a couple of check valves as a precaution against gases intermingling where I did not want them to. With this set up, I have one bottle of argon and one of CO2 so I can have either or both for my MIG or TIG machines depending on which I'm using. I used these check valves:

https://www.mcmaster.com/#check-valves/=18j8jam

I set both regulators to the specified 50 psi and adjust the flows as necessary to get the mix I need. I'm doing only hobby grade stuff, so exact mixtures are not crucial to what I am doing. I set this up when I got my TIG machine as I share tanks between my welders and this let me add Argon to my MIG gas. The addition of Argon over straight CO2 for MIG was a revelation for me, It runs so much nicer.

The manifold is simple and effective. It did not cost much to make and has been really handy.

The valves are small ball valves, the yellow is CO2, black is Ar. The hoses on the bottom go to the reg/flowmeters on the bottles. So gas flows through the valve, then the check valves directly above then the tee. The black hose on top goes to whichever welding machine I happen to be using. I've been planning to add valves to swithc between machines as well, but am too lazy thus far. Anyhow, Here it is.

Get yourself a Western Quick Connect for the Hose to Machine. Simple and incorporates a check valve. I use them on all my machines and tanks. Allows immediate disconnect and swapping of tanks/gas between processes and machines.

Here's an example:
http://www.advancedtools.com/western-en ... gJDKvD_BwE

cj737 wrote:Get yourself a Western Quick Connect for the Hose to Machine. Simple and incorporates a check valve. I use them on all my machines and tanks. Allows immediate disconnect and swapping of tanks/gas between processes and machines.

Here's an example:
http://www.advancedtools.com/western-en ... gJDKvD_BwE

This is an excellent solution. Thanks!