October 2016 Flyer Page 5 Basics of Airbrushing

5 Prep work and priming Before you paint a model, clean it to remove any impurities that might affect paint adhesion or detract from the overall finish. The easiest way to clean a model is to wash it in warm, soapy water. Keep an old toothbrush handy to clean any hard-to-reach areas. After the model is clean, shake off the excess water, put it on a lint-free towel, and set it in a dust-free place such as a cabinet. Plastic, metal, and some resin models can be cleaned with this technique. Commercial cleaners are also available for the various modeling mediums. Alcohol-based cleaners help remove mold release, silicone, and grease from plastic. Tarnished brass models can be cleaned with powdered copper cleaner, available at most grocery stores, and an old toothbrush. With the prep work done, you should spray the model with an undercoat, which ensures that the final color or colors are even throughout the model. Light gray is a good, all-purpose undercoat color. Painting and masking Before you start spraying a model, test the paint on a similar material. This way, if the paint mix is too thin or not thinned enough, you won't ruin Fig. 6 Sharp separation lines. A favorite modeler's trick is to put masking tape on a piece of glass, lay a steel straightedge over it, and cut a strip using a hobby knife with a fresh no. 11 blade. Use the cut edge to mask the separation line between colors. Fig. 7 Removing the mask. Even though the paint is dry, it can still peel off if you're not careful. Slowly pull the masking tape up and away at an acute angle from the last color applied. Don't leave the tape on the model too long, or it will leave residue on the model. To make sure your paint is clean (and stays that way), never shake the jar. When shaken, paint gets onto the lip of the jar and dries into clumps. These clumps can fall into the paint and clog your airbrush. Putting a screen filter on the siphon tube will help keep clumps out of the airbrush. Straining paint is an additional way to keep out foreign matter. After the paint is remixed, find a thinner that's clean (free of lint and dust) and compatible with the paint you're using. Any impurities in the thinner will get in your paint and on your model. Acrylic and organic- solvent-based thinners can't be used interchangeably. In a separate jar, thin the paint until it reaches the consistency of milk. After your airbrushing session, empty the thinned paint into a waste-paint container. Never dump it back into the original jar. Most manufacturers print the recommended thinner-to-paint ratio on the side of each jar, but consider that a starting point. Different colors (and bottles of paint) react differently. Thin the paint, spray it, and adjust as necessary. Weathering mixes must be thinned more than regular airbrush mixes. However, pigments settle fast in paint thinned for weathering, so stir it regularly or add a few drops of flow enhancer. your model. Once you're satisfied with the paint flow, start spraying. Hold the airbrush between 3" and 4" from the model and apply the paint with a smooth, even stroke, as shown in fig. 4 . Start spraying beyond one end of the model, smoothly move the airbrush across the model, and stop spraying beyond the other end. Apply the paint in light coats, overlapping the edge of each stroke until the model is evenly covered. The paint should go on wet and shiny but dry quickly. If you apply the paint too heavily or don't let it dry completely between coats, it'll get thick and develop runs. If it goes on dry, you'll have a rough finish. You may need to rotate the model while airbrushing to get paint into hard-to-reach areas, and that's where a paint handle proves helpful, such as the handle shown in fig. 5 , but you could also use a wood block. To gain experience with the airbrush, start with models that require only one color, such as a boxcar. When you feel more confident, try painting models with multiple colors. To prevent the second color from getting onto the first, the model will have to be masked. Regular 3M masking tape or the firm's blue painter's tape work well. However, masking tape doesn't have a perfectly straight edge, so you'll need to put a

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