Editor's Note: While foraging around the web one day looking for parts for my Iwata, I stumbled across Jay's website. Since I have a profound respect for anyone who can draw and airbrush, I spent some time on his site...and his work is incredible, even if it's not ships :-) Although these articles are written for aspiring airbrush artists, modelers can learn alot from folks like Jay. I'd like to thank Jay for allowing us to use his articles to help out modelers who are intimidated by airbrushes, and to those who are just getting started. Thanks Jay!
The airbrush is an air tool, and requires compressed air to operate. In most cases, the best source of compressed air is an electric air compressor. There are many choices to the beginning artist to choose from when buying a compressor. Almost too many; the selection can be a bit overwhelming.
But do not despair! With a few helpful pointers, I hope to make the selection process much easier.
First thing to consider is how much air your airbrush needs. Most models will get by with .5 CFM at 20 PSI. What does that mean in English? Well, CFM stands for cubic feet per minute, and refers to the volume of air that a compressor generates. PSI stands for pounds per square inch, which refers to the actual pressure that the air is built up to. .5 CFM at 20 PSI is actually a very small amount of air, and all but the cheapest of compressors will be able to pump out this much air. Does that mean that you can just buy the second cheapest compressor on the market? Yes and no. .5 CFM at 20 PSI is the absolute MINIMUM that your airbrush will work at. It will give you no room to play with at all. It's best to get a compressor that will give you a bit more than the minimum to accommodate some experimentation on your part with PSI settings. Also, you will want a compressor that can keep up with your airbrush sessions. The cheaper compressors tend to overheat quickly, leaving you without an air source.
There are compressors especially made for the airbrush, and there are models that are general purpose compressors that will power a variety of air tools including the airbrush. General purpose compressors usually have much larger motors, but are also much louder. You'll have to decide if noise is going to be a factor in your work environment. Just how loud compressors are is something that varies from one model to another. It pays to shop around a bit. In general, it is best to avoid models that have plastic covers on the motors, and opt for models made entirely out of metal.
The next big distinction in compressors is whether or not it has a storage tank. Some models are just electric motors attached to pumps which feed air directly into your airbrush. The better quality models will have either an auto shut off feature, or a bleeder valve, which will prevent air from backing up into the motor and causing it to strain and overheat. The advantage to these compressors is that they are small and lightweight, making them very portable and appropriate for a small studio where space in an issue. They are also less expensive that tank models. It is also fairly easy to upgrade a tankless model to a tank model, if you have a bit of skill with tools.
The compressor with an air tank is simply the same electric motor and pump described above, only it is attached to an air tank. When the tank is full, the auto shut off turns off the compressor. When the air drops down to a certain level, the compressor is turned back on. These models are much better for long painting sessions, but are much larger and heavier than tankless models.
Some models of tank compressor are oil lubricated. You will have to check the oil level and add oil once in a while to make sure it continues to run properly, just like a car. Other models are 'oil free' and don't require any such maintenance. On all tank models, you will have to drain the tank at the end of every painting session to prevent rust from forming inside the tank.
No matter what type of compressor you get, there are two things you will need to add on, if it does not already have them. The first is an air regulator with a gauge. This will allow you to set the exact amount of air that you are spraying at. The second is a moisture trap. This will prevent moisture from building up inside the air line and blowing out your airbrush, causing unexpected bursts of water from spitting out the tip while you're working. Some types of moisture traps fit right onto the airbrush hose, other types are screwed onto the compressor's air port. You can also buy a regulator moisture trap combo that does both jobs. Those are a bit expensive, but very nice. Whether you buy a regulator and moisture trap separately, or an all in one unit, you should make sure that the fittings match the compressor and your airbrush hose. Most compressors and air brush hoses have 1/4" fittings, but regulators and moisture traps come in 3/8" fittings and 1/4" fittings. Make sure you get the right ones. Also, make sure you have all male to female connections. You don't want to try to attach your airbrush hose to the regulator and find out that they are both female fittings.
Also, if you are airbrushing with flammable paints like enamels and urethanes, it is a good idea to keep the compressor at least 20 feet away from the painting area to avoid fire hazards. So buy a long hose!
There are other options for compressed air besides the electric compressor. One good option is compressed gas. CO2 is the most common choice. CO2 tanks can be purchased from welding supply shops, and restaurant supply companies (CO2 is used to carbonate drinks in soda fountains and beer on tap.) The only advantages to CO2 over compressors is that there is no noise at all, and no need for electricity. The disadvantage is that you have to keep bringing it back to the supply shop for refills. A ten pound tank will last about ten hours of continuous airbrushing. In the long run CO2 is much more expensive than a compressor. Also, if you use too much of a volume of air at once (like if you had two airbrushers hooked up to the same tank) the regulator can freeze, causing the air pressure to go way up unexpectedly. But if you are going to be airbrushing outside, it is nice to not have to worry about an extension cord. Because CO2 displaces oxygen, it is not a good idea to airbrush indoors with CO2 without fresh air ventilation. A respirator or spray booth without outside exhaust wont cut it. Without fresh air ventilation, the CO2 content will rise, at fist making breathing difficult and making you very tired. Eventually you could pass out.
The only other choice for air is the can of airbrush propellant. This is a small can of aerosol, which you can hook up to your airbrush hose with an adapter. They only last about an hour at best, so in the long run they are your least economic option. Also the aerosol fumes are toxic. The only advantage at all is that the initial cost is low, and they are very portable. I strongly recommend not wasting money on airbrush propellant.
Over the years I've used the Badger 180-11, the Paasche D, and now I'm using a Badger 180-22. All three are nice tankless compressors, and all three have special qualities. The Badger 180-11 was the most quiet. The Paasche would run for hours without overheating, and had the least vibration. And the Badger 180-22 has the greatest output. I've sold the fist two compressors, and as far as I know they both are still running fine.
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