Probably the biggest investment you will make when starting airbrushing is the compressor. When I started out I was told to buy the biggest I could afford, and I think this is good advice.
A quick overview of the way compressors function is that at the heart of the machine is a compressor pump. The pump sucks in air through an inlet valve and compresses it through an outlet valve. If you have an air tank/receiver with the compressor, it can be stored. Depending on the size of the tank and the amount of air used by your airbrush, spray gun, air tool etc will determine when the compressor pump automatically cuts in to replenish the air used. If you have a small pump, it will obviously have to work harder, which will cause it to heat up quicker. This is when it becomes a problem as the heated air passes through, it condenses to water, which means it will end up being expelled through the airbrush with the paint. Also if you have an air tank, the tank will start to fill with water and again you will find water coming through your airlines. How do you overcome or reduce this problem? By buying a compressor with a bigger pump. It means less work, thus less heat generated.
Ok, it’s time to buy a compressor, what next? First of all if you are in the beauty make up industry or food industry then you will require an ‘Oil less compressor,’ Which means the air leaving the compressor has no oil residue in it, the air is ‘clean air.’ If you do a Google search for oil less compressors, you should be able to find a selection for your country.
An example shown above of oil less compressors suitable for cake and food decorating. We would also recommend a compressor like this for airbrush make up. Try and go for the one with the biggest air output which you will find measured in CFM or L/Min.
Now for the rest of us. We have a choice of two types of compressors, a silent or a standard. A silent compressor sounds a bit like the refrigerator compressor you have in the house, it won’t drown out the TV or conversation. If you live in an apartment block then this is something I would recommend. The down side is that they are a lot more costlier than a standard. We use a silent compressor in the studio plus a back up. Also when we do exhibition work, we have a smaller one for demoing.
Above is an image of the type of silent compressor we use for everyday airbrushing. It’s produces 3.5 cfm (100 l/min) air output with a 50 litre tank and can sit in the studio without any problems.
Above is our demo silent compressor. It’s portable, has a 24 litre air tank and 1.77 cfm air output. For large air volume requirements we use a standard compressor, very useful when using HVLP spray guns..
The standard compressor is much cheaper than a silent compressor but is a lot noisier and any sound in the local vicinity will be drowned out as soon as the compressor starts up. If you have an out house or aren’t too concerned about the noise then this is a good choice as you can have a much more powerful compressor for the price of a smaller silent compressor. Remember the compressor only starts up when the tank is almost empty so depending on the size of tank and the amount of air used, you may only have to listen to it starting up a few times a day.
CFM CFM CFM, this is what we look for when we buy a compressor. This is the amount of air volume that your compressor produces abbreviated as CFM (Cubic feet per minute) Or L/min (litres per min) The bigger the volume the stronger the compressor pump and the ability of the compressor to replenish the air.
Example 1: I am in my studio airbrushing and the compressor fires up while I’m spraying. After the air tank is full, the compressor automatically turns off, while I am still spraying. This means that the compressor has the ability to replenish the air while I am using the airbrush.
Example 2: Now I decide to spray a panel with my spray gun. The compressor fires up and keeps working. Now instead of a nice clean spray pattern, the spray gun starts to splutter and the paint is intermittent. This is because the compressor can not replenish the air in time because the motor is not strong enough. The problems this creates are obvious, a bad spray job, build up of moisture in the air lines and a burnt out compressor.
An airbrush uses about .5 cfm
A HVLP spray gun can use 10cfm upwards
Bear this in mind if you intend using a spray gun for larger areas or finishing.
Compressors should come with a combined pressure regulator and moisture trap as shown below.
Compressor maintenance
The moisture trap also has a filter which helps reduce moisture and oil deposits from entering the airline. Once every couple of months we clean it with a brush and by soaking in thinners.
After long periods of use, the air tank starts to build up with moisture which needs draining. At the underside of the tank is a drain valve which enable us to remove any water which has built up in there. We usually do this once a week.
Airlines and adapters
There are a few ways to connect the airbrush to the compressor. This is how we do ours. We use quick fit connectors throughout, it’s quick and simple and gives us flexibility to add and subtract airlines.
Fig 1
Fig 1 shows our airbrush hook up. The manifold contains six female and one male quick release connectors. It connects to the main airline on the right which goes back to the compressor. There are many ways to lay out your air system. This is a simple one that suits us.