Getting Paint to "Stick" - Paint Brushing basics

Non-sticking paint is usually caused by surface contamination, so cleaning is the first thing to try. Sidsnook, you may want to be sure that you are using the proper thinner in the right proportions. Practice on a piece of plastic sheet or an old model to see what works best, then make a record. If you are using a cleaner with a detergent or debonder to thin paint, such as window cleaner or Acryl cleaner, these will destroy the ability of the paint to bond to the surface. Also, if your airbrushing location is too cold, this may affect the ability of the paint to stick.

Well i dont know what the best primer is, i dont have my offhand to tell you i just finished it. Go to your hobby store. I think i actually used primer from a around-the-house project i did, it wasnt even for models but it did the job. acrylic paint clogs up and dries in airbrushes sometimes so your trouble may be that not the plastic. Maybe you thin it too much or with the wrong thing (isopropryl alcohol for acrylic+s, mineral spirits for enamels). If you mean fine details like a ridge etc. mask it off just on the feature, airbrush around it and then paint teh feature carefully by hand with a single stroke direction to make it blend in with the airburhsed part. I dont actully model aircraft often, but i hope that helps.

I just bought a new airbrush system and have used it for my first 2 airplane projects. I too have difficulty getting acrylic piaint to stick to either plastic or resin models. I have tried washing the parts with soap, and then denatured alcohol but the problem persists. A suggestion is to use a primer.

1. What type of primer works best?
2. How do you keep multiple layers of piant from "washing-out" the fine details of a models surface?

if its a fu=igure, assemble the figure and use primer to give paint something to stick to and also to identify seems. Vehicles should also be primed, anything should. Airbrushing doesnt always require priming.

You didn't specify whether you were using flat or gloss, enamel or acrylic. In general, the plastic surface needs to be clean of mold release. Washing in warm soapy water helps. I often use Windex cloths. Usually, flat paints have a higher ration of pigment to binder, and will often cover better. Paint has to be mixed thoroughly to cover well. Stirring with a stick or piece of sprue works. Most enamel paints can be shaken to complete mixing, but some acrylics will get bubbles in the paint if shaken. Certain colors also may not cover as well as others because of their chemical composition and cost leading the manufacturer to use only the minimum amount of pigment. Reds and yellows use expensive pigment. It also helps to use quality brushes. For a gloss finish, you might try Acryl gloss coat. For propeller blade tips, an old trick is to paint the blades in the main color, usually black, and them dip the tip of the blade in the yellow paint up to the right depth. This works well in 1/72 scale. Additionally, you may find that a second coat may be needed to get a good finish with white, yellow or red.