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135
Powering your Airbrush - A Propellant Source Primer

Propellant
I don’t want to use the term Air as there’s several methods of Powering an airbrush. The major requirements for propellant are:
  1. The propellant must be in the Pressure range of the airbrush (or other tool).
  2. Sufficient Volume. Volume is related to pressure although not the same. Think of it like a water hose, the volume is controlled by the Nozzle on the end, in this case the regulator. (more on them later)
  3. The moisture content of the propellant. You need you’re propellant to be “dry” or it can and will affect the quality of the paint job. Air contains Moisture. Carbon Dioxide and Nitrogen can be used and they don’t contain any moisture.
Based on the list above, here are the most common Choices.
Propellant Can
Image 1 The propellant can is just that; a Can of propellant. It’s made by several companies that make Airbrushes. It’s basically a can of spray paint without the paint.
Advantages
  • Inert gas (no moisture)
  • Disadvantages
  • Limited amount of propellant
  • When used they get extremely cold, causing a pressure drop.
  • Expensive over time. At about $10-15 each, several will pay for a compressor
  • Compressed Gas
    Carbon Dioxide and Nitrogen are the most commonly used gases. You can get the bottles or cylinders in a variety of sizes. These are generally used for Welding gas and soft drink dispensing equipment. The 20 cuft is probably the easiest to deal with. Cylinders can be expensive to purchase but leasing is available from most gas suppliers. The Regulator can be a bit expensive as well. The cylinders can last 6 months or more depending on how much airbrushing you do.
    Advantages
  • Silent - need I say more?
  • Completely dry
  • Consistent pressure until the very end of the tank.
  • Relatively inexpensive $12-15 per fill (20 cuft)
  • Disadvantages
  • can be heavy (depending on the size of the tank)
  • must be secured to prevent a tip over (Have you seen the Mythbusters Episode?)
  • air tanks
    Image 2
    Most people who have one don’t have the space for a compressor. They’re great for filling tires.
    When it gets empty you can take it to the local service station for a refill.
    Advantages
  • Silent
  • Disadvantages
  • Limited amount of pressure (dictated by the equipment filling it)
  • You’ll need a moisture trap as it is compressed air
  • You’ll need to do some plumbing on the tank to make it useable for airbrushing
  • Air Compressors
    I’m going to divide this section up into a few sub sections as there are a few different types of air compressors (there are actually more than listed here but the remaining ones are industrial types well above the needs for hobbyists / homeowners.) Images 3 through 9 show various types.
    Hobby compressors
    Image 4
    Generally some of the small diaphragm type compressor falls under this category. They’re design for occasional use. The smaller ones from Testors and others.
    Advantages
  • Relatively inexpensive
  • Relatively quiet
  • Disadvantages
  • Heavier use will do damage to the internal parts.
  • Airbrush compressors
    Images 5 and 6
    These are specifically designed to moderate to heavy use airbrushing. Generally used buy T-Shirt artists, nail salons and anybody who airbrushes hours at a time. Several models to choose from that range from completely silent in operation to some that are slightly noisy.
    Advantages
  • Relatively quiet
  • Fairly long lasting
  • Disadvantages
  • Expensive
  • General Purpose Air Compressors
    Generally used by the homeowner for air powered tools. They come in a wide range of shapes and sizes. There are two general types: the oil lubricated and a non oil lubricated type. The oil lubricated ones have two different types: single stage and double stage cylinders. They will all have tanks ranging from 1 to 80 or more gallons.
    Types of “General Purpose” Compressors
    Oil-less Pump have coatings on the cylinder parts to lower friction. They are the Noisiest of the large compressors. Images 7 and 8
    Single stage Reciprocating compresses the air in one cylinder, usually a cast iron or iron sleeved aluminum cylinder. From there it is fed into the tool/airbrush. Image 9
    Two Stage Reciprocating compresses the air in two successive cylinders, usually a cast iron or iron sleeved aluminum cylinders. Image 10
    Advantages
  • Depending on the size, large volume and higher pressures require compressor to run less.
  • Disadvantages
  • Size (of larger models)
  • Moisture you’ll need a moisture trap for all Air compressors.
  • Other items needed
    You may need to have some of these other items for a successful airbrush setup.
    Regulators: anything in a tank will need some kind of a regulator to limit the pressure coming out of the tank. This is a 2 stage regulator for compressed gas cylinders. Image 11
    This is a single stage regulator for compressed gas cylinders. Image 12
    This is a regulator for an air tank or compressor that doesn’t already have one installed. Image 15
    Moisture trap These are to collect any moisture that was compressed along with the air by the compressor. The most ideal location for a moisture trap is as far as possible from the compressor itself. This allows the air to cool, releasing the moisture. Image 13
    Air filters - Tanks tend to rust on the inside from the moisture in the compressed air. Be sure to drain the tank periodically based on the manufacturers’ instructions. Image 14
    You can get Filter/Regulator/Moisture trap combinations. Image 15
    Noise
    Air compressors can be noisy. Some of the quieter Hobby and Airbrush models start about 30 db (about the same as a refrigerator). The larger General Purpose compressors average 60-100 plus db.
    The oil-less models tend to be louder than the oil lubed type. There are some hobby compressors that are lower in db but you will pay more for the “Silent” models.
    See the chart
    OK, now you’re thinking; “What should I get?”
    Well you’re the only one that can answer that. I have a small rebuilt (approx 60 yr old) Dental compressor (Thanks Dave!!!), A 20cuft CO2 tank that I use for Airbrushing, As well as a 33 gallon compressor out in the garage for air tools. If you want the ultimate in Silence I’d opt for the Airtank or Compressed Gas. They can run the same cost as a small compressor. If a compressor is what you’re thinking take the time to do the research. Look for online reviews of the particular models you’re thinking about. If you use an air nailer or other air tools get a compressor sized for them. A compressor can never be too big for an airbrush. The only real limit is where the compressor itself can go and that may also determine where you can spray as well.
    • 1_propellant
    • 2_tanks
    • 3_airtank
    • 4_testors
    • 5_diaphragm
    • 6_tankeddiaph
    • 7_minicomp
    • 8_minioiless
    • 9_oiless
    • 10_2stagecomp
    • 11_2stagereg
    • 12_singlereg
    • 13_moisture_trap
    • 14_filter
    • 15_Regulatore-filter_moisture_trap
    • 16_noise1

    About the Author

    About Matt Leese (matt)
    FROM: NEW YORK, UNITED STATES

    Design Drafter By trade.............Modeler and Woodworker for Fun. Got into modeling I don't remember exactly when..........


    Comments

    Nice feature, Gents! Lotsa good info and photos...good job, Matt! ~Gunny
    MAR 07, 2007 - 12:00 AM
    Nice feature. Thanks Matt and Scott. This is why I love KitMaker... I learn something new every day! I never knew about the compressed gas and tank options in so far as airbrush/spray gun propellant. Thanks again guys
    MAR 07, 2007 - 12:53 AM
    It was actually a Fun one to Write. I do need to take a updated pic of Grumpy's "Old Faithful" that A gave another life too!!! Now, I know some might be asking.... Paintball tanks.......... I didn't cover them in the article as they're not Widely used. However I'd be weilling to say that they can be used as a Power source as well. it'd just be a matter of getting the Correct fittings and a Regulator for the CO2 or Nitrogen. I honestly don't have an Idea as to the "life" a 7,9 or 20 oz Paintball tank. I tried to cover the Most commonly used "propellents" Obviously I didn't cover any of the "industrial" type compressors like the Rotary Screw, Centrifugal & Axial varietys (they kind my employer builds on a very LARGE scale) Any other Questions... feel free to ask.
    MAR 07, 2007 - 01:22 AM
    Nice article Matt.
    MAR 07, 2007 - 02:14 AM
    Nice article, and very informative. Thanks Matt.
    MAR 07, 2007 - 05:05 AM
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