How do I mix silicone correctly for mould making?

Choosing Your Silicone and Understanding Ratios

Silicone for mould making is typically sold as a two-part system, labelled as Part A and Part B (or base and catalyst). Most easy-to-use products, like “Pure Mould” – Translucent Liquid Silicone Rubber for Mould Making and silicone putties, require a straightforward 1:1 ratio by volume. Always check the specific product instructions, as some specialist silicones may differ.

Mixing Technique: Tips for Consistency and Bubble Reduction

Once you’ve measured equal amounts of both components, combine them in a clean, dry container. Stir thoroughly but gently, scraping the sides and bottom repeatedly to ensure full integration. Stirring too quickly or vigorously can introduce excess air, leading to unwanted bubbles in your finished mould. When using liquid silicone, tapping the container lightly on a surface after mixing can help bubbles rise and pop. Some makers use a vacuum or pressure pot, but careful manual mixing still delivers excellent results for most projects.

Practical Guidance for Better Moulds

• Work in a dust-free environment to avoid trapped debris.
• Use a flat stick or spatula for mixing and avoid whisks or drills unless specified.
• Once mixed, pour the silicone from one side of your mould box, letting the material flow around your model—this also helps bubbles escape.