Liquid RTV Silicone Rubber for Mold Making Plaster/Cement/Concrete Molds

This is often due to adding too much silicone oil, which destroys molecular weight, or adding too much catalyst (more than 2%), which reduces tension and tear strength. Also, using high-hardness silicone for small intricate designs or low-hardness for large simple designs can cause issues.

Burnout occurs when using unsaturated resin without demolding the product within 3 minutes, as the resin generates significant heat. Our silicone rubber contains special materials to resist high temperatures and help avoid this problem.

Condensation silicone rubber solidifies by absorbing moisture from the air. To ensure shelf life, we dry out the water in the rubber. Solution: Add 0.05% water and stir briefly at low speed before use.

Weak tear strength is caused by adding too much silicone oil to reduce viscosity, adding excessive catalyst (more than 5%, we recommend 2%), or using the mold prematurely. We recommend waiting 24 hours after mold completion and using an outer protective mold.

Poor tension results from adding too much silicone oil to make the rubber easy to operate, which makes it too soft. This reduces tensile and tear strength, leading to short service life and fewer mold turnovers.