Getting a Smooth Finish from a Spray Can

The rough, dusty coat from a spray can usually starts before the paint reaches the model. The can is cold, the paint is not mixed, the spray starts on the part, or the coat is put on too wet. Each problem has a bench habit that prevents it.

Spray cans work well for primer, clear coats, and single-color finishes. GSI Creos Mr. Hobby B515 Mr Surfacer 1200 Gray Spray Can can prime a kit without setting up an airbrush. GSI Creos Mr. Hobby B513 Mr. Super Clear Gloss 170 ml Spray Can can prepare a surface for decals or seal work already done.

Warm, Shake, Test, and Spray in Light Passes

• Warm the can in warm water. Put the closed can in a container of warm tap water for a few minutes. Warm paint atomizes better than cold paint. Wipe the can dry before spraying so water does not drip on the model or the bench.
• Shake it longer than seems necessary. The pigment and carrier need to be mixed before the nozzle can do its job. Shake the can after warming it, and shake it again during a long spraying session.
• Test spray away from the model. Spray onto scrap plastic, cardboard, or the inside of an old kit box. This clears any heavy first spit from the nozzle and shows whether the spray pattern is even.
• Hold the can at a steady distance. Most spray-can work is done with the nozzle several inches from the surface. Too close floods the surface. Too far leaves dry paint grains before they can level. Use the can directions as the first guide, then judge by the way the paint lands.
• Start each pass off the model. Press the nozzle before the spray reaches the part. Move across the model at a steady pace. Release the nozzle after the spray has passed the far edge. This keeps the heavy start and stop points off the surface.
• Use several light coats. A light first coat gives the next coat something to grip. Add more light passes after the previous coat has set according to the can directions. One wet coat is the common route to runs, soft detail, and uneven sheen.

Dusty Coats, Runs, and Humid Air

A dusty finish usually means the paint dried before it reached the surface. Move the can a little closer, slow the pass slightly, or work in a warmer space. Do not bury the rough coat under one heavy coat. Let it dry, smooth it if needed, and return with light passes.

Runs come from too much paint in one spot. The usual causes are spraying too close, moving too slowly, or pausing at an edge. Keep the can moving before, during, and after the pass.

Humidity is hard on spray work, especially clear coats. Damp air can leave a milky or pebbled finish. If the air feels wet, wait for a drier day or spray in a controlled space with good ventilation. Follow the directions on the can for drying and recoating.