How Long Does RTV Silicone Rubber Take to Cure?

Typical Curing Times for RTV Silicone Rubber

Cure times vary by product and formulation. Fast-cure options, such as “Pure Mould” Translucent Liquid Silicone Rubber, can be ready in 3–8 hours, making them ideal when time is of the essence. Most bi-component RTV silicones, which require mixing of two parts, will typically cure in about 10–12 hours. It’s essential to follow the manufacturer’s guidelines for best results, as temperature, humidity and mixing accuracy can all influence curing time.

Practical Tips for Faster or Reliable Cures

• For urgent or same-day projects, consider fast-curing silicone rubbers specifically designed to set in under 8 hours.
• Ensure a precise 1:1 mix ratio when using platinum-based quick-curing formulas to promote even curing.
• Bi-component systems need careful mixing and accurate catalyst addition for full strength after the recommended time.
• Avoid disruptions during the curing phase—moving or demoulding too soon can compromise edge detail and longevity.

When Cure Time Really Matters

Shorter curing times are especially useful for high-turnover or professional mould-making environments, as well as craft projects with deadlines. In contrast, slower-curing systems may be preferable when working with large or thick moulds to reduce the risk of bubbles or shrinkage.