Sanding Resin Projects: Smooth and Glossy Finishes (400–3000 Grit Guide)

Resin crafts—such as jewelry, coasters, and tabletops—often cure with uneven edges, drips, or surface imperfections. Sanding is the key to transforming rough resin into a flawless, glass-like finish. This guide covers the grit sequence, tools, and steps for professional-quality results.

Why Sand Resin?

Resin hardens into a durable surface, but it can trap bubbles, dust, or ridges. Sanding levels out imperfections and prepares the surface for polishing. Without sanding, resin projects may appear dull or cloudy.

Best Tools for Resin Sanding

• 9x11 in silicon carbide wet/dry sandpaper sheets
• Sanding block or foam pad
• Bowl of water with a drop of dish soap
• Microfiber cloths
• Polishing compound

Recommended Grit Sequence

• 400 grit: Flatten uneven edges or drips.
• 800 grit: Smooth surface after coarse sanding.
• 1200 grit: Remove fine scratches.
• 2000 grit: Pre-polish refinement.
• 3000 grit: Final sanding for a glassy finish.

Step-by-Step: Sanding Resin

1. Start with 400 grit. Wet sand uneven areas until flat. Use 400 Grit (25-pack).
2. Move to 800 grit. Smooth scratches left by coarse sanding. Try 800 Grit (50-pack).
3. Refine with 1200 grit. Create a satin-like surface. Stock up on 1200 Grit (100-pack).
4. Polish with 2000 grit. Light sanding prepares for final shine.
5. Finish with 3000 grit. Achieve a crystal-clear, pre-polished surface.
6. Polish. Apply resin-safe polishing compound with a microfiber cloth or buffer.
7. Seal. Optionally apply a thin resin topcoat for maximum gloss.

Special Cases

For deep casting imperfections, start with 220 grit before progressing through the sequence. Always wet sand resin to reduce heat and dust.

Pro Tips

• Use plenty of water while sanding—resin dust is harmful if inhaled.
• Sand in alternating directions with each grit for uniform results.
• Keep light pressure; let the sandpaper do the work.
• Polish in stages for the clearest finish.

Aftercare

• Clean resin projects with mild soap and water only.
• Store sandpaper flat and dry for reuse.
• Apply UV protectant to resin pieces exposed to sunlight.

FAQs

• Can I dry sand resin? Wet sanding is strongly recommended to avoid dust and melting.
• Do I need to sand all the way to 3000 grit? For maximum clarity, yes—but 1200–2000 grit may be enough for matte finishes.
• What polish should I use? Use a plastic or resin-specific polishing compound for best results.

Watch & Learn

For crystal-clear resin finishes, shop our full range of wet/dry sheets in the Super Fine Sandpaper Collection.