The perfect mold
every time with silicones for concrete casting
Concrete casting stone materials allows you to reproduce detailed designs to create stone columns, wall sidings or other decorative pieces to make accurate copies of a specific design. To ensure that your design is reproduced accurately each time, it is important to have a mold made from the right material.
In many cases, polyurethane and latex materials are used in concrete casting processes. These materials have high and inconsistent levels of shrinkage. High shrinkage of materials does not provide the level of dimensional stability needed to produce high quality faux stone molds or stone veneer molds. Silicone has low shrinkage, excellent release characteristics, and provides the dimensional stability required to produce highly accurate part geometries for modern aesthetics and precision.
The polyurethane and latex material not only shrink during the manufacturing process, but they also do not hold color pigmentation. The color of manufacturing stone is very important as the first stone produced should match the thousandth stone produced perfectly. When using concrete to manufacture artificial stone, silicone is a great solution for color pigmentation because it is hydrophobic. Pigments used in concretes are water-based, so the pigments are easily disbursed in the silicone mold. The consistency of color from part to part is very important for both architectural and landscaping color matching of stones.
Benefits of silicone for concrete casting:
- Fast cure – makes a ready-to-use mold in 8 hours or less
- Easy mold release
- Detailed reproduction
- Accurate part geometry
- High color fidelity due to pigment retention
- Low scrap rate
Elkem Silicones’ Bluesil™ RTV products are the materials of choice for creating high fidelity reproductions.
Bluesil™ RTV 3433 is a two component, silicone elastomer which produces flexible molds with excellent detail reproduction and outstanding mechanical performance.
Bluesil™ RTV 3420 is a two component, silicone system which cures at room temperature by a polyaddition reaction (10:1 ratio) resulting in a low modulus soft silicone elastomer that is perfect for corner mold applications.