Sanding Plastic Models: Smooth Prep for Painting and Detailing

Plastic model kits—cars, airplanes, ships—look best when surfaces are perfectly smooth before painting. Sanding removes mold lines, fills imperfections, and prepares the plastic for primer and paint. With the right sandpaper grits, your models will look professional and detailed.

Why Sand Plastic Models?

Plastic parts often come with seam lines or sprue marks from the molding process. Sanding smooths these flaws, helping primer and paint adhere evenly. Without sanding, imperfections remain visible and paint may peel or look uneven.

Essential Tools

• Wet/dry silicon carbide sandpaper
• Sanding sticks or files for fine work
• Sanding sponges for curved surfaces
• Magnifying lamp for precision
• Tack cloth and microfiber rags

Best Sandpaper Grits for Plastic Models

• 400 grit: Remove mold lines and sprue marks (400 Grit (100-pack)).
• 800 grit: Refine scratches and prep for primer (800 Grit (25-pack)).
• 1500 grit: Smooth primer coats before painting (1500 Grit (50-pack)).
• 2000–3000 grit: Final wet sanding for glossy finishes.

Step-by-Step: Sanding Plastic Models

1. Inspect parts. Look for mold lines, sprue marks, or rough edges.
2. Start with 400 grit. Sand gently to remove imperfections.
3. Switch to 800 grit. Smooth scratches and prep for primer.
4. Prime. Apply primer, then lightly sand with 1500 grit for an even base.
5. Paint. Use thin coats, sanding lightly with 2000–3000 grit if needed between layers.
6. Polish (optional). For high-gloss models, finish with ultra-fine sanding and polish compound.

Special Cases

Clear plastic parts (like canopies) require very fine sanding (2000–3000 grit) followed by polishing to avoid cloudiness. For small details, fold sandpaper into strips or use sanding sticks.

Pro Tips

• Always wet sand plastic to prevent melting and dust buildup.
• Use light pressure—plastic scratches easily.
• Check progress under good lighting to catch flaws early.

Aftercare

• Handle sanded parts with clean hands to avoid oils before painting.
• Store leftover sandpaper flat to prevent curling.
• Polish finished models occasionally to maintain shine.

FAQs

• Do I need to sand new model parts? Yes, light sanding removes mold lines and improves paint adhesion.
• What grit is best for primer sanding? 1500 grit ensures smooth, even coverage.
• Can I sand painted models? Yes, use 2000–3000 grit for polishing between coats.

Watch & Learn

Sanding makes plastic models look professional and realistic. Stock up on ultra-fine sanding sheets to take your model-building projects to the next level.