Flow regulator for airbrushing with CO2?

[Marc_G]

Hi folks,

I've been having fun learning to airbrush with acrylic paints, using my 5 pound CO2 cylinder with a traditional pressure regulator, running the Paasche brush with H5 tip in the low 40's PSI.

Eventually ran out of CO2 and bought from Craigslist a 20 lb tank nearly full, and it came with a regulator calibrated for flow in like liters/min and cu ft / hr.

Is the flow-based regulator any different from the pressure-based regulator? In other words, is it the same works with just different units on the dial? Or is there a fundamental difference in how it works?

In the meantime I just moved my pressure regulator to the new cylinder, but I was wondering if the flow regulator would work just as well as the pressure regulator at some particular flow setting.

I bought the larger cylinder because the cost per pound of CO2 is much lower when getting a 20 lb cylinder filled versus the smaller 5 lb one.

The new regulator was kind of a bonus. Craigslist rocks.

 

[luke strawwalker]

A flow type regulator is used for MIG welding where the pressure of the gas is virtually nil, but there has to be sufficient gas flow to keep the weld isolated from the atmosphere. I don't think it's gonna work worth a rip for airbrushing... you really want a steady reliable regulated PRESSURE not VOLUME for airbrushing.

Can you not swap the regulators out?? It should just be screwed onto the valve body of the cylinder. Make sure the bottle valve is closed tightly and loosen the flow regulator with a wrench, and screw the pressure regulator on and snug it up a bit with the wrench (don't make it EXTREMELY tight-- snug is good enough.) Open the bottle valve and check for leaks with soapy water. Snug a bit if necessary.

If the threads or fitting size is different, you should be able to get an adapter at any welding shop...

Later! OL JR

 

[Marc_G]

Thanks JR I've already moved the pressure regulator to the new cylinder but was wondering if the flow regulator might be good to use.

The flow regulator will likely be paired with the old 5 lb cylinder and used for aquarium purposes next year.

Craigslist rocks. A 20 lb cylinder full of gas plus a regulator for about a hundred bucks. :headbang:

 

[luke strawwalker]

Thanks JR I've already moved the pressure regulator to the new cylinder but was wondering if the flow regulator might be good to use.

The flow regulator will likely be paired with the old 5 lb cylinder and used for aquarium purposes next year.

Craigslist rocks. A 20 lb cylinder full of gas plus a regulator for about a hundred bucks. :headbang:

Umm... ok...maybe I'm missing something, but WHY would you want to put CO2 in your fish tank?? Seems like a quick way to kill your fish...

You could probably just craigslist the flow regulator and make a good chunk of your money back that you spent on the tank and regulator combo...

Those regulators are used for MIG welding and aren't exactly cheap... you should be able to pawn it off pretty quickly for a decent amount...

Later! OL JR

 

[Marc_G]

Umm... ok...maybe I'm missing something, but WHY would you want to put CO2 in your fish tank?? Seems like a quick way to kill your fish...

You could probably just craigslist the flow regulator and make a good chunk of your money back that you spent on the tank and regulator combo...

Those regulators are used for MIG welding and aren't exactly cheap... you should be able to pawn it off pretty quickly for a decent amount...

Later! OL JR

My favorite fish tanks are big planted freshwater aquaria. The plants suck up a lot of CO2 and actually cause the water to become pretty alkaline if the CO2 isn't supplemented. If you supplement with a bit of excess CO2 (a bubble or two per minute, into the filter, let's say) and it gets absorbed into the water, the plants just about explode with growth (and the fish like it too...). Salt water tanks also often use CO2 buffering.

Granted, excess CO2 could drop the pH and kill 'em off, but most water has enough CA/MG 2+ ions to buffer the CO2 and hold things at a good pH.

I used the pressure regulator for this purpose but had to add a needle valve to get down to the low flow I wanted. Maybe with the flow regulator I can have a better solution... will test it out, after I get the tank going next year. It's been dormant 6 years.

Marc

 

[luke strawwalker]

My favorite fish tanks are big planted freshwater aquaria. The plants suck up a lot of CO2 and actually cause the water to become pretty alkaline if the CO2 isn't supplemented. If you supplement with a bit of excess CO2 (a bubble or two per minute, into the filter, let's say) and it gets absorbed into the water, the plants just about explode with growth (and the fish like it too...). Salt water tanks also often use CO2 buffering.

Granted, excess CO2 could drop the pH and kill 'em off, but most water has enough CA/MG 2+ ions to buffer the CO2 and hold things at a good pH.

I used the pressure regulator for this purpose but had to add a needle valve to get down to the low flow I wanted. Maybe with the flow regulator I can have a better solution... will test it out, after I get the tank going next year. It's been dormant 6 years.

Marc

Learn something new every day... Thanks!

Yes, the flow regulator is probably EXACTLY what you need for this application then... it's made to run at very low output pressures (MIG welding uses a nozzle about the size of a dime that the welding wire emerges from surrounded by a bath of gas, which "submerges" the weld and protects it from atmospheric oxygen and nitrogen when the metal is a liquid and as it cools and becomes solid at the back of the weld puddle-- contact with atmospheric oxygen or nitrogen or water vapor (containing hydrogen) can embrittle the weld and cause all sorts of problems... hence the flow regulator which is set depending on how much gas flow is needed for the thickness of metal being welded and the amperage the welder is operating at, which together with the thickness of the metal and rate the wire is fed into the weld puddle determines the size of the puddle, and therefore the size of the area that needs to be 'submerged' in the welding gas...

You SHOULD be able to dial the flow regulator down to practically nothing, unlike a pressure regulator...

Later and good luck! OL JR

 

[Marc_G]

Thanks!

Great to know.

The guy I bought it from said he was experimenting with "home carbonation."

The great thing is he told me where to get gas cheaper than the place I had been using before.