[BobP]

Joshua, water vapor under high pressure in your compressor tank condenses into water as it is released into lower pressure inside your airbrush hose, then is pushed through the airbrush and onto your crankbait, splattering the surface. The same principle applies to oil if you use a compressor that has to be oiled. So the ideal setup is to have an oil filter (if needed) and a moisture trap connected to the compressor. They are inexpensive and sold at most home centers that carry compressors and air tools.

You also want a regulator to control air pressure. Maybe your compressor already has one. You only really need one regulator somewhere in the system so you can run your airbrush at between 30-50 psi. But the finer control you have over air pressure, the better you can control the airbrush spray pattern. Finer lines and shading work best at lower pressure. That's why a MAC valve on an airbrush is handy. Compact in-line regulators that attach between the airbrush and its air hose are also available, as are pressure regulators that attach to the compressor outlet and have a twist knob and a psi gauge. It's about control + convenience + cost. Airbrushes with MAC valves are the most expensive option but perhaps the handiest. An in-line regulator is also handy but may be a little unwieldy connected to the airbrush. The regulator on the compressor is the cheapest but is not handy if you are running a big compressor over in the corner, 6 ft away from your airbrush. All of them work. You need at least one of them. You can mix and match them as you choose for convenience.