How to Seal All Gaps and Edges for Resin Table Moulds

How to Seal All Gaps and Edges When Making a Resin Table

Sealing all gaps and edges when building your mould is an essential step in making a successful resin table. Proper sealing prevents resin leaks and ensures a clean casting.

Why Sealing Is Important

Even the smallest gap in your mould can lead to resin escaping, which not only wastes material but can also ruin the shape and finish of your table. A well-sealed mould helps you achieve tidy edges, minimises mess, and ensures the resin sets exactly where you want it to.

How to Effectively Seal Your Mould

After assembling your formwork, carefully inspect each joint and corner for small gaps. Silicone sealant is widely used for this job and is included in some starter kits like the “River-Table” Complete Kit. Apply a generous bead of silicone along every inner edge, smoothing it with a finger or tool for a snug seal. Allow the sealant to cure fully before pouring resin. For extra security, many makers use a special release film beneath the project to help remove the finished table and further prevent leaks.

Tips for Reliable Results

Always use a stable, flat base, like an MDF board, for your mould.
Double-check every seam before pouring.
Make sure sealant is fully cured—uncured filler can affect your finished edge.
Test your mould with a small amount of water if you’re unsure about the seal.

When This Matters Most

If you’re pouring thick layers of epoxy or designing a complex tabletop shape, perfect sealing is even more critical. Large volumes of resin under pressure will find any weakness in your mould.

Related guides

How To Make A Resin Table

By carefully sealing every gap and edge, you avoid leaks and ensure your resin table project goes smoothly from start to finish. For more detailed guidance on the complete building process, see our main How to Make a Resin Table guide.