What Ratio of Paraffin Wax Should I Use with Polyester Resin?

Recommended Ratio for Polyester Resin

For a tack-free finishing coat, add paraffin wax at 1–2% by weight to your polyester resin mixture. This addition helps prevent the surface of the resin from remaining sticky after curing, ensuring a dry and sandable finish. Carefully weigh out the wax: for every 100g of polyester resin, use 1g to 2g of paraffin wax, blending thoroughly for an even result.

Mixing and Application Tips

• Melt the paraffin wax gently before mixing with your liquid polyester resin if required, ensuring the wax is well dissolved and evenly dispersed.
• Add your hardener only after the wax and resin are properly combined.
• Apply the mixture as your final layer to seal the surface and promote proper cure.

For reliable paraffin wax, consider Paraffin Wax – for Craft Candles, 500g Granulated Wax which is suitable for use in craft and resin-related applications.

When the Paraffin Wax Ratio Matters Most

The precise wax-to-resin ratio is particularly important when you require a sandable, glossy finish—such as with the outer layer of fibreglass work or clear, smooth projects. Too little wax can leave the surface tacky; too much may affect clarity or bonding, so sticking within the 1–2% guideline is best.