How to Use Spray Paints for Smooth and Even Coats on Plastic Models from Diorama kit's blog

Spray painting plastic models is one of the best ways to achieve a smooth, even finish that enhances the realism of your builds. However, mastering the art of spray painting can be challenging for beginners. Whether you’re painting a military vehicle, a robot, or a figure, getting those perfect coats without drips, orange peel effects, or uneven surfaces requires practice, patience, and the right techniques.

In this guide, we’ll walk you through the process of using spray paints effectively on plastic models, covering everything from surface preparation to final top coats.

Spray paints offer a few distinct advantages over hand brushing or airbrushing:

• Smooth, Even Coverage: Spray best paint for plastic modelsapply thin layers that distribute evenly across the model, minimizing brush strokes and inconsistencies.

• Quick Application: Spraying covers large surfaces faster, making it ideal for vehicles, armor, or any model with extensive surface area.

• Great for Base Coats and Primers: Spray paints are often used for priming or applying a base coat, creating an even foundation for detail work or weathering effects.

Not all spray paints are created equal, and choosing the right one for plastic models is essential for getting smooth, professional results.

1. Acrylic Spray Paints

• Water-based and typically non-toxic.

• Dries quickly and is easy to clean up.

• Works well for most model types and surfaces.

2. Enamel Spray Paints

• Oil-based and more durable than acrylics.

• Slower drying time, which may allow for better flow and leveling.

• Ideal for models that will be handled frequently, as they resist chipping and wear.

3. Lacquer Spray Paints

• Solvent-based and extremely durable.

• Offers the smoothest finish but can be more challenging to work with due to quick drying times.

• Requires proper ventilation and sometimes a protective top coat to avoid reactions with other paint types.

Some popular brands for spray paints tailored to plastic models include:

• Testors: Offers enamel spray paints in a variety of historical colors.

• Rust-Oleum: Suitable for larger projects but often requires more practice to achieve fine finishes.

• Krylon: Often used for priming, with options that bond well to plastic surfaces.

Before you even think about spraying your model, thorough preparation is crucial. Without proper prep, even the best spray paint can lead to subpar results.

• Plastic models are often coated with mold-release agents that prevent paint from adhering properly. Wash your model with warm soapy water and a soft brush to remove these agents.

• Let the model dry completely before moving to the next step.

• Use fine-grit sandpaper (around 800-1000 grit) to smooth out any imperfections, seams, or flash from the molding process.

• Sanding ensures the surface is even and ready to accept paint, which helps prevent lumps or uneven patches.

• For intricate models, use masking tape or liquid masking solutions to cover parts that should not be painted.

• This is especially important when working with multi-colored models or sections requiring separate painting steps.

• Priming the model is essential for achieving a smooth and durable finish. It helps the paint adhere better and creates a uniform surface.

• Choose a primer that is compatible with your type of spray paint (acrylic, enamel, lacquer). Spray primers are often available in neutral shades like white, grey, or black.

Shaking the can is more important than most people realize. It ensures the paint is mixed evenly, which helps prevent clumps or inconsistent coverage.

• Shake the spray paint can for at least 1-2 minutes to thoroughly mix the paint.

• For best results, shake periodically throughout the painting process, especially if the can sits unused for more than a few minutes.

Before you spray directly onto your model, test the paint on a piece of scrap material or cardboard.

• This allows you to check the spray pattern, paint flow, and color intensity.

• Make any necessary adjustments, like holding the can farther away or closer depending on the coverage you’re aiming for.

One of the most important rules of spray painting models is to apply thin, light coats.

• Hold the spray can approximately 6-12 inches from the model.

• Begin spraying off the model, then sweep across in a smooth, even motion, stopping only after you’ve passed the model.

• Avoid staying in one spot for too long—this causes excess paint buildup, leading to drips or uneven surfaces.

• Let each coat dry fully before applying the next. This could take anywhere from 10 minutes to an hour, depending on the type of paint.

Pro Tip: Don’t aim to cover the model completely in one go. Multiple thin layers will build up color smoothly without overwhelming the surface.

Once you’ve applied your final coat, allow the paint to cure fully. Curing times can vary based on paint type and environmental conditions (humidity, temperature), but typically it takes around 24 to 48 hours.

• Rushing this step can result in fingerprints, smudges, or a tacky finish that ruins all your hard work.

A clear coat adds durability and enhances the look of your model. You can choose from gloss, satin, or matte finishes depending on your desired final effect.

• Clear coats are particularly useful when using decals or weathering techniques, as they help seal in the paint and protect it from wear and tear.

• Apply clear coats just like your base paint: thin, even layers with adequate drying time in between.

Holding the can too close to the model can result in excess paint buildup, leading to runs or drips. Aim to maintain a consistent distance (6-12 inches) to prevent this.

Always shake the can thoroughly before starting. Inadequate mixing can lead to uneven paint flow, resulting in splatter or inconsistent color.

Applying too much paint at once is a common mistake. Thick coats can obscure details and cause a rough or bubbly texture. Instead, focus on building up color gradually with multiple light layers.

Patience is key when spray painting. Allowing each coat to dry properly prevents the paint from smudging, cracking, or peeling.

Spray painting is best done in controlled environments. High humidity can cause the paint to dry unevenly, while cold temperatures can lead to poor adhesion and a dull finish. Aim for a workspace that’s around 65-85°F with low humidity.

Spray painting plastic models can deliver a smooth, professional finish that is difficult to achieve with a brush. By selecting the right spray paint, properly preparing your model, and using the correct technique, you can transform your models with flawless, even coats of paint. Remember that practice makes perfect, so don’t be afraid to experiment with different spray paints and finishes to find what works best for your projects.