Recently, I switched over to CO2 to power my airbrush. I really like the quiet and the “clean air” but I sure didn’t get much “mileage” out of my 20lb. bottle. I will be really lucky if I can finish the 1/48 Shinden I’m painting now. The gauge that displays tank pressure started around 1000psi, it’s now down to 100 after about 5 spraying sessions. Does anyone have any experience with these? Is that rate of use about right? If it is, then it’s gonna get kinda expensive refilling for each project. Thanks for your help, Gary.
Gary,
I can’t discern your spraying habits, but I can give you the basic math to help you figure out approximate spray time. Most full size gas bottles (the ones you see in oxyacetylene torching setups, for example) have a maximum volume of about 6 cubic feet. Making an assumption that your bottle is about half that size, then the volume should be around 3 to 3.5 cubic feet. If you multiply 3.5 cu.ft. times the pressure on your regulator (1,000 psi) and then divide by 14.7psi at sea level to adjust for standard pressure, you get 238 standard cubic feet. If your airbrush is being powered at, let’s say, 10 cfm, then your total (continuous) spray time is only going to be about 24 minutes before you’re going to need a refill.
I hope this helps you answer your question.
Depending on how long and how often you spray, the cost of refills, and the trouble you have to go through (traffic, distance, gas, etc.) to get your refills, you may want to consider a small compressor, or a compressor with an attached tank, if noise is an issue.
Also, keep in mind that your cylinder is required to be hydrostatically tested every 5 years. Unless you have a maintenance agreement with your CO2 supplier, that would, I assume, be an additional expense.
Gip Winecoff
Whoa, are you a math wiz or something syrene?![:O] You about blew me away! But I think all those calculations deserves reconition! Good job on the calculations![tup][8D]
it last’s long enough to get a compressor [:p]
Gary,
Something is definitely wrong there. A 20 lb CO2 tank should last about 8-10 hours at 60 psi! I know T-shirt artists who spray all day at 60 psi with one 20 lb tank, so at maybe 20 psi for airbrushing models you should get several more hours than that by far.
Is it possible you have a leak or the tank was not filled properly?
Mike
how much did you turn the valve? i know from personal experience that a 50 pound tank will last for about 3 monthes, at least on the mig welder
thanks for the replies. MikeV, my thoughts exactly. That’s why i’m puzzled about this. How could I check the tank for leaks? I’m leasing it for a year and the guy at the welding supply place just brought the bottle out to my car; i guess it could have been "short’ to start with…?
1337, how much should i turn the valve? i’m a beginner with co2 and i welcome any advice.
styrene, thanks for the math. that stuff was hard for me in school! Thanks for the advice.
Gary
Gary,
The easiest way to check for leaks is to spray some soapy water on the fittings with a spray bottle. You will see bubbling where the CO2 is leaking, if it is.
I would call the place you got it from and tell them about it.
Mike
Tex: i dont know about how much the co2 tank should be turned, but for an inert mix of co2 and argon (45:65) for a millermatic MiG welder, valve is turned 2 times. not wayyyyyyyy to much… i never had a co2, cause i started out w/ 1 can of gas and a compressor.
sorry for the double post, but too lazy to edit.
those arn’t your 20 pound co2’s, they are about 6 and a half feet tall, a foot wide, and weigh about 50-75 pounds.