• An airbrush is equivalent to a miniature spray gun.
• Air blows over the paint nozzle, creating a suction that draws the paint up.
• The paint then flows out into the air stream, breaks into fine droplets, and flies in the direction the air/airbrush is pointed.

• Two basic variations: single-action and double-action.
• Single-action brush: The trigger button controls the air-flow through the airbrush. Paint flow is controlled by a nozzle, typically in-line with the paint line.
• Double-action brush: The trigger button controls both the airflow and the paint supply. Pushing the trigger button down increases the airflow, and pulling back the trigger allows for more paint flow.
• Big difference: The mixing of air and paint significantly differs between the two types. Typically in a single-action airbrushes the paint nozzle meets the the airflow at an angle. The air travels out of the brush and across the tip of the adjustable paint nozzle. On most double-action airbrushes the paint nozzle and air nozzle are parallel. The air flows around the end of the paint nozzle, where the paint needle controls the amount of paint released.

• Try to dilute your paint so it is the consistency of milk.
• Always add/pour the thinning agent into the paint, not the other way around.
• I've had good success using wind shield fluid (the blue window cleaner stuff) as a diluting agent for Gunze Aqueous Hobby Color paint.
• Remember, flat paint dries much more quickly the glossy paint, watch those fingerprints!

Cleanup:
   Some of the info below paraphrased from Aztek's site.

• ACRYLICS and LACQUERS.

  When working with Gunze Sangyo Aqueous Hobby Color I typically use generic windshield washer fluid or drinking water (not name brand but the dispensed stuff) for both cleanup and thinning. Works pretty good.

  If you used: Boyd, Model Master Car Colors, Model Master FS colors, Model Master II, Testor, Racing Colors

  If paint is wet...
  	#1789 Model Master Airbrush Thinner, #1799 Model Master Airbrush Thinner # 8824 Testor Airbrush Thinner, #8825 Testor Airbrush Thinner, #1148 Testor Thinner, #1156 Testor Brush Cleaner (Not for spray through)
  If paint has dried... Solvents are not effective so don't let acrylics and lacquers dry in your brush. However, some cleaners will soften the paint, try:
  	#5098 Acrylic Enamel Cleaning Solution RC Thinner, #2018 Model Master Lacquer Thinner, #1419 Model Master Lacquer Thinner, #1159 Lacquer Thinner, #522142 Floquil ELO Remover 2 oz.,#542143 Floquil ELO Remover 8 oz., #552144 Floquil ELO Remover 16 oz.

  I normally use the Model Master Airbrush Thinner when I work with the Testor Model Master acrylics. Most of the Model Master acrylics are thinned pretty well right out of the bottle. I just add a little of the thinner and it sprays well and drys fast. I also use Model Master Airbrush Thinner thinner for clean up while working with this brand.

  As for lacquers, I usually use Testor Dullcote. I thin it with generic turpentine and clean up with generic paint thinner, both of which are the strong stuff you'd find in a local hardware store.

• ENAMELS.

  Because there are no commonly available solvents for enamels, it is very risky to use them in an airbrush. If at all possible, enamels should be avoided. If they are used, wash them thoroughly and immediately with thinner. This will stop them from setting up. If enamel paint does dry in your airbrush, soak the components in oven cleaner for as long as possible (preferably 24 hours) and then flush. Where possible, use acrylics or lacquers instead of enamels.

Operation:

• Cleaning - When spraying acrylics, cleaning the model is very important. Unlike enamel paints, water-based acrylic does not contain enough solvent to cut through oil including greasy finger prints. Before proceeding, proper care should be taken to remove these oils.
• Paint Viscosity Air Pressure - There are two basic paint viscosities, gloss and flat. The thinner the paint the better it sprays. Flat paint generally spays better than gloss. When spraying thicker gloss paints, compensate by increasing the air pressure if possible. Flat paints spray well at 20 to 25 lbs., while gloss may require 10lbs more. This will vary from color to color. Please keep in mind that a propellant can will instantly give pressure of 50 to 70 psi. This pressure will soon drop.
• Keeping a Wet Edge for Gloss Coats - To spray a good gloss coat, always keep a wet edge. To adopt a wet edge, spray covering the complete surface as you paint. Don't spray lightly. If you spray lightly, you will build up spray from one side to the other and all the small granules of paint will dry and a grainy finish may result. Try not to over coat the finished paint while it is still wet. Doing this may also result in a matte grain finish in certain areas.
• Keeping the Sprayer Clean - Never let buildup occur on the front of the spray nozzles. This will cause spiting and as a result debris will be sprayed onto the model. Stop Blockages in Pouch Paint As the pouch is sprayed the paint siphon may not work well. To increase the siphon effect, attach a paper clip to the bottom of the pouch. This will force the paint level to rise in the pouch making the siphon more efficient.

An Acrylics Primer:

• Acrylics dry extremely fast in comparison to enamels. When sprayed, flat acrylic dries in seconds. A gloss dries in minutes and reaches full cure in only hours. This high speed drying allows for a fast work pace. A cockpit can be painted, detailed and finished in less than an hour because you don't have to wait for parts to dry.

• Good Adhesive - While not having the adhesion of enamels, acrylic still bonds well to most surfaces, including styrene, resin, and brass. It can also be used on surfaces that enamels won't adhere to, such as vinyl.

• High Gloss The new acrylic finish is equal to enamel in gloss (reflectance) but is more durable. Acrylic is essentially plastic, so when it dries, a plastic film forms. This film is impervious to most solvents, so it stands up to solvents in polishing compounds.

• Hard Wearing - In addition to being very hard and solvent resistant, the acrylic finish can be sanded, polished and buffed very easily without damage.

• No Crazing of Clear Parts - There are no solvents in acrylic that will react with styrene. If paint gets onto clear styrene, it can be removed without damaging the clear styrene.

• Ideal for Washes - Acrylics are inert to solvent-based paints, which make them the ideal base for enamel washes. Using a gloss coat as the base (flat coats act as a collector, not letting the enamel run off the surface), brush your thinned enamel onto the acrylic and let it settle into the cracks and crevices. Once the enamel is dry, coat again with clear gloss acrylic and repeat the process until you are satisfied with the finish.

• Tips - Generally acrylic is a poor surface for glue. Always clean off the dry paint before you glue to a surface.

  Always wash your model thoroughly in soap and warm water before you start your modeling to achieve the best adhesion possible especially if you intend to mask your model.

  Do not thin acrylics too much because they loose the cohesion as a formula and will have a tendency to scratch easily.

  If the finish color is not even and you find gloss and flat next to each other on the same color, simply gloss coat or flat coat the entire surface.

One of these days. . .
Air Sources
Ventilation