Masking and Acrylic Model Paints

Acrylic paints are great. No volatile compounds, less smell and easier cleanup. But if you have ever tried to mask over acrylic model paints, you've probably experienced the frustration of pulling the masking away and half the paint with it. Even a fingernail can remove the paint if accidentally dragged over it. Acrylic paint just cannot stick to bare styrene which has no 'tooth' to cling to. But you can use tape to mask over acrylic paint with proper preparation.

The answer is to use an enamel primer. Enamel paint creates a chemical reaction with the plastic allowing it to cling to the smooth styrene surface. In turn, the surface of an enamel primer creates 'tooth' to which the acrylic topcoat can stick.

 

Priming your models is fairly easy to do and less hassle then top coating with enamel paints. I use a Testors rattle can of gray primer (No. 28137). This can usually lasts for two or three projects. Do not use automotive primers as these are very thick and can quickly obliterate surface detail.

Keep the spray can at least 8" (20cm) from the model surface

Hold the can at least 8" away from the object to be sprayed (to avoid flooding panel lines and surface details) and give it a good all-around coating. Always begin the spray stroke behind or in front of the model and sweep over the model with an even motion. Paint can accumulate in the spray nozzle and cause splattering when the nozzle is first depressed or released, and you don't want that splatter to end up on your model. Allow to cure according to the manufacturer's directions and you are ready to apply an acrylic top coat capable of being masked.

Begin the sweep away from the model

Sweep all the way over the model and then release the spray nozzle

Regular masking tape has too much adhesive for use in model work. You can use tapes specifically made for model masking, which come in narrow widths and have a lighter adhesive, or you can use blue painter's tape which is available at most home centers. This can be cut into thinner strips with a hobby knife.

Whatever kind of tape you use while working over acylics, it helps to stick the tape down to something other than your model first and then peel it way before applying it to your model. This removes small amounts of the adhesive from the tape, making it even less likely to remove your acrylic topcoat.