Is a Catalyst Needed for Liquid Mould Silicone?

Why Use a Catalyst with Liquid Mould Silicone?

Liquid Mould silicone rubbers are designed as bi-component systems, meaning they consist of two parts that must be combined to set and cure. The catalyst, also known as the curing agent or hardener, is always required. It triggers the chemical reaction that transforms the liquid silicone into a flexible, solid rubber, making it possible to demould your finished piece with all the fine details intact.

How to Mix and Apply the Catalyst

For best results, always follow the manufacturer’s recommended mixing ratio, usually provided in the instructions. Begin by weighing the base silicone and catalyst accurately according to these guidelines. Mix thoroughly, ensuring no unmixed material is left on the sides or bottom of your mixing container, as incomplete blending can result in soft spots or areas that simply won’t cure. Once combined, pour the mixture into your prepared mould box and allow it to cure undisturbed. Liquid Mould silicone typically has a working (pot) life to allow careful handling before it begins to set.

When This Matters Most

• If the catalyst is omitted or measured incorrectly, the silicone will not cure, resulting in wasted materials and time.
• Catalyst is especially vital for reproducing complex details or casting multiple moulds, where consistent results are essential.