Should You Sand Between Epoxy Layers? Practical Guide

Building up your epoxy resin project in multiple layers can create depth and strength, but proper adhesion between layers is vital. You may wonder if sanding is necessary to ensure the best result.

Why Sand Between Epoxy Layers?

When working with thick or multi-layer epoxy projects, sanding the cured surface before adding a new layer helps new resin grip and bond more effectively. This gentle abrasion gives the next layer a slightly roughened surface to anchor to, reducing the risk of layer separation or visible boundaries. Skipping this step can sometimes lead to imperfections or weaker adhesion, particularly if much time has passed between pours or you are working with deep layers as found in table casting.

How to Sand and Prepare Between Layers

Once the previous layer is fully set, lightly sand the surface with fine-grit sandpaper—just enough to dull the smooth, glossy finish. After sanding, ensure you clean away all dust and any residue using a soft, damp cloth or suitable solvent before applying the new layer. For thick castings such as those made with deep pour resins, sanding also helps maintain clarity by minimising trapped bubbles or imperfections.

When This Matters Most

For multi-pour tables, river tables, or deep castings: sanding improves adhesion between each thick layer.
If more than 24 hours has passed between layers, sanding becomes even more beneficial.
For thin, fresh coats poured soon after each other, sanding may not be essential but can still add value for a flawless finish.

Related guides

How To Dry Epoxy Resin

Taking the time to gently sand between epoxy layers is a simple but crucial step for sturdy, professional results—especially on large or deep projects. For more epoxy layering tips and troubleshooting, visit our main guide on how to dry epoxy resin.