The key factors in properly spraying an airbrush are operating air pressure, amount of material being released by the airbrush, and the distance the airbrush is being held from the surface being sprayed.
For fine lines the airbrush should be held as close as possible to the surface with a small amount of material being released, for broader spray coverage the airbrush should be held 4 ” to 6” from the surface being sprayed with a larger volume of material being released.
NOTE: The airbrush will produce overspray. This is the “fuzz” of dots that sprays outside of or around the spray’s desired focal point. If a sharp edge is desired, a masking medium (stencil, frisket, low-tac masking tape, spray shield, etc.) must be utilized when airbrushing.
There are some simple learning exercises that can be practiced to help develop skill, comfort, and confidence in using the airbrush: creating a grid of dots (on a blank sheet) with your airbrush – then going back and connecting the dots, drawing figure eights, and/or simply writing your name with the airbrush. These are all basic, but effective, airbrushing exercises. Using your airbrush to color in coloring books is also a very helpful, skill developing, method of airbrush practice. To practice airbrush technique on three dimensional objects, paint items such as scratch plastic/metal, pop cans, shampoo bottles, or other contoured items that are of little or no value.
Step one: The key to keeping an airbrush clean is to not let material set up (dry) in it. This can be done by simply spraying the appropriate cleaning agent through the airbrush with reasonable frequency (when changing color and when setting the airbrush to rest for any period of time). Three important things to remember: 1. Your cleaning agent should be determined based on the material you are using, not the airbrush you are using 2. Material dries as fast in an airbrush as it does on the surface it is being sprayed on to. 3. Anything you think will take 2 seconds will take 2 minutes, and anything you think will take 2 minutes will usually take at least 20 – so spray the cleaner.
Step two: Should material set up (dry) in the airbrush, it may be necessary to back flush the airbrush. This is done by suffocating the air flow of the airbrush at the nozzle by carefully “pinching” a soft cloth or paper towel over the nozzle’s end. This will deflect the air back into the airbrush chamber and loosen any dried material, sending it into the cleaning bottle. If done correctly, the cleaner will bubble during back flushing. It is advisable to spray fresh cleaner through the airbrush after you have back flushed it.
Step three: On what should be rare occasions it may be necessary to disassemble some parts of the airbrush for more thorough cleaning. This should only be done if the user has neglected to do step one of regularly spraying cleaner through the airbrush, and/or step two of back flushing is unsuccessful in getting the airbrush to spray properly again. If disassembly is required, it should be only of parts that come in contact with the sprayed material; from the material’s point of entry into the airbrush and forward. The included parts for disassembly are the nozzle assembly and the needle. To thoroughly clean the nozzle assembly, use an ultrasonic cleaner or denture cleaner (yes, denture cleaner – follow the directions on the package). The needle should simply be wiped down with a soft cloth saturated with the appropriate cleaning agent. If residue on the needle is still apparent it may be removed by gently rubbing a fine steel wool over the residual deposit area. While the needle and nozzle are removed from the airbrush it is OK to run a pipe cleaner saturated with cleaning agent through the chamber of the airbrush, following the same path as sprayed material, and out the airbrush front. For bottom feed airbrushes that is up the stem and out the front, for gravity feed airbrushes it is down the color cup and out the front. Only do this when the needle and nozzle are removed as forcing anything through the nozzle will damage it. After using the pipe cleaner, blow out the airbrush to remove any pipe cleaner “fuzz”. After all nozzle/needle cleaning steps are complete the airbrush can be reassembled and will be ready for use. This disassembly process should be rarely necessary if steps one and two are followed, but it is recommended if storing your airbrush for an extended period of time.
1) Bubbling in color reservoir (color cup or jar). When this occurs it is the result of air incorrectly being deflected into the paint channel. This concern can have several causes; the most common are tip dry, incorrect spray regulator/air cap alignment, or a split paint tip.
If tip dry is the cause, remove the dried paint from the needle/nozzle tip by either picking it off with your finger tips/nails or spraying cleaner through the airbrush. If tip dry occurs frequently in your application it may be helpful to keep a paint brush and small container of water nearby to wet the nozzle and get your airbrush spraying properly again when necessary. Tip dry will usually occur more frequently in detail airbrushing applications.
If you think the bubbling may be occurring due to incorrect spray regulator/air cap alignment tighten or loosen your spray regulator/air cap in ¼ turn or lesser increments to determine if that is the certain cause of the problem. If it is, your airbrush will stop bubbling and resume spraying once you hit the spray regulator/air cap’s “sweet spot”.
If a split paint tip is the cause of the bubbling, the only corrective measure is to replace the paint tip.
2) Off-center spray. This is caused by a bent needle tip. As media exits the airbrush it “rolls” off of the needle. If the needle is bent it will cause the spray to “lean” to one side or the other. To correct this problem carefully attempt to straighten the needle tip. A grooved sharpening stone is an effective device for trying to straighten airbrush needle tips. If you are unable to straighten the needle tip, a replacement needle will need to be installed to correct the off-center spray concern.
3) Spray will not shut off and/or occurs without sliding the trigger back. This concern can have several causes; the most common are improper seating of the needle in the paint tip, a “flared” pain tip, or partial tip dry.
If the needle is not seated properly in the paint tip, it is necessary to re-seat it. To do so access and loosen the needle chuck, slide the needle forward until it stops and seats in the paint tip, and re-tighten the needle chuck. DO NOT USE FORCE when seating the needle in the paint tip, when it stops it should be seated properly.
If the spray will not shut off due to a flared tip, it is necessary to replace the paint tip.
If the spray will not shut off because of partial tip dry/clogging remove the dried paint from the needle/nozzle tip by either picking it off with your finger tips/nails or spraying cleaner through the airbrush.
4) Spray pattern pulsation. This concern can have several causes; the most common are a bad seal (usually one that cannot be trained to properly play well with other seals, LOL, just kidding – we do have a sense of humor though), inconsistent media viscosity (usually paint being too thick), or an inadequate or improperly performing air compressor.
A bad seal can occur anywhere air could potentially leak from in its path from the air source through the airbrush. If you are experiencing a pulsation in your airbrush spray it is advisable to check all threaded parts to make sure there is no air leakage at the threads. This includes the hose connections at the airbrush and the air source. If an air leakage is found it should be sealed. This can usually be done effectively with the wrapping of Teflon “plumber’s” tape around the male threaded part. Many airbrushes also have inner seals that the needle passes through. These seals are designed to make sure paint is properly directed to the airbrush nozzle and does not flow to the rear of the airbrush. If the airbrush’s inner seal is not correct it can also cause a pulsating spray. To fix a bad inner seal it is necessary to replace it. In many instances this seal replacement is best done at the factory by the airbrush’s manufacturer. (This is a lifetime warranted part on Badger airbrushes).
If spray pulsation is caused by an inconsistent paint viscosity, the paint should be adjusted to proper spraying viscosity. It is also important to make sure that paint is properly blended so that pigment is evenly distributed through the paint to ensure spray consistency. The rule of thumb for preparing paints (or other materials) for airbrushing is to reduce them to the approximate visual viscosity of 2% milk. As starting paint viscosities often vary from color to color, even within a specific paint brand, it is best to avoid fixed thinning ratios. It is also best to vigorously mix/stir paint, rather than shaking it, before use. Mixing/stirring paint better blends pigment and base creating a more consistent paint from the top to the bottom of the bottle. Mixing/stirring paint also causes pigment to re-settle slower.
If paint pulsation is caused by an inadequate or improperly performing air compressor, it may be necessary to have the compressor repaired or replaced. Over time air compressors can incur diminished performance that can adversely affect their performance efficiency. This is especially noticeable with small “tankless” diaphragm compressors that can present pulsation of the diaphragm action in an airbrushes spray pattern if the compressor operates inefficiently.
5) Grainy spray. This is caused by paint (or other media) not being properly reduced, meaning it is too thick to atomize properly, or not operating the airbrush at a high enough pressure.
Paint (or other media) should be the viscosity equivalent of 2% milk to spray properly through an airbrush. Sparingly add the appropriate thinner to the paint (or other media) until it is the proper sprayable viscosity. Also check the needle tip and nozzle tip to make sure no tip dry has formed on the nozzle.
A bottom feed airbrush should have at least 16 PSI (higher for heavier media) while spraying to operate properly. A gravity feed airbrush can be operated at spray pressures as low as 8 PSI. Check the pressure you are spraying at to be sure it is high enough for the type of airbrush you are using, and the type of media you are spraying.
6) Buckling surface. This is caused if paint (or other media) is too thin or “runny” or applied too heavily on a thin porous substrate (usually a rag type paper). If working close to the surface take care not slide the airbrush trigger back too far releasing more paint than desired and over saturating the surface you’re spraying. You should only work close to the surface when wanting to do fine lines, and only sliding the trigger back a little bit. If working with an extremely thin media apply it in fine coats, letting one coat dry before applying another. This will prevent over saturating your surface and give you greater control in developing your artwork to your desired end.
7) Paint blobs at the ends of the stroke or barbell patterns. This is caused by sliding the trigger back before beginning your hand movement and stopping your hand movement before and not sliding your trigger forward to shut off paint flow before stopping your hand movement. This can only be remedied by being aware of your triggering and practicing proper triggering techniques. Practice, practice, practice. Creating a grid of dots (on a blank sheet) with your airbrush – then going back and connecting the dots, drawing figure eights, and/or simply writing your name with the airbrush all airbrushing exercises. Using your airbrush to color in coloring books is also a very helpful, skill developing, method of airbrush practice. Practice, practice, practice.
8) Flared ends or curved stroke. This is caused by turning the wrist at the end of the airbrush stroke or arcing closer to the surface during the airbrush stroke. Unless these spray pattern effects are desired, it is important to maintain consistent parallel distance from the surface you are spraying through your entire airbrush stroke. This again is best corrected by practicing and developing your skill level and a comfort with how the airbrush works. Creating a grid of dots (on a blank sheet) with your airbrush – then going back and connecting the dots, drawing figure eights, and/or simply writing your name with the airbrush are all good airbrushing practice exercises. Coloring in a coloring book with your airbrush is also a helpful, skill developing, method of airbrush practice. To practice airbrush technique on three dimensional objects, paint items such as scratch plastic/metal, pop cans, empty plastic bottles, or other contoured items that are of little or no value.
9) Centipede or spidering spray patterns. This is caused if paint (or other media) is too thin or “runny” or applied too heavily on a non-porous substrate (metals, plastics, etc.). If working close to the surface take care not slide the airbrush trigger back too far - releasing more paint than desired. On hard surfaces excess paint cannot be absorbed and will scatter over the surface in a centipede or spidering pattern. When wanting to do fine lines and working close to the surface you should only slide the trigger back a little bit to release a small amount of media. If working with an extremely thin media apply it in fine coats and let one coat dry before applying another to avoid a “scattering” effect when air (and additional paint) passes back through still wet paint. The probability of this undesired effect is increased if spraying your airbrush at too high of an air pressure, so check to make sure your air pressure is properly set for the type of airbrush you are using, the media you are spraying, and the type of surface you are finishing.
10) Dot blotching or splattering at the start of end of spraying. This is caused by an incorrect triggering technique of stopping air flow (releasing downward trigger pressure) before turning off paint flow (sliding trigger/needle forward to close off paint tip). By turning air flow off before paint flow, paint goes around the needle and “floods” the nozzle. The result of this “flooding” is either one of two things. 1. As the needle returns forward upon releasing the trigger, it pushes the paint that has flooded the paint tip out in a burst or splatter of blotched dots. 2. If possibility 1 does not occur the “flooded” paint remains in the nozzle and is blown out in a burst or splatter of blotched dots when the trigger is depressed to resume airbrushing. This is another technique issue that can be prevented by learning and developing proper triggering technique. Remember to carefully slide the trigger back forward to stop paint flow, don’t let it “snap” back.
The only thing that you cannot be taught is practice. The more you practice your airbrushing the greater your airbrush skills will become and the more your airbrushing confidence and enjoyment will increase. (See tip #8 above for a few recommended triggering practice techniques)