PLATINUM ASF 40SH 1 kg silicone for mold making

Product detailed description

Platinum silicone ASF 40SH for strong and durable molds

ASF 40SH is a platinum (addition) cured silicone designed for the production of stronger molds with high dimensional stability. A hardness of around 40 Shore A means the mold is significantly stiffer than with softer silicones – it holds planes, edges, and angles excellently, which is useful for larger flat castings or frequent use.

The silicone is primarily designed for casting epoxy resin, but after testing compatibility, it can also be used with other systems suitable for platinum silicones (selected polyester or polyurethane resins). The silicone has low shrinkage and transfers model details well.

When to choose ASF 40SH?

• Molds for coasters and panels – round and square coasters, decorative plates, tiles, panels, slabs,
• Molds for flat and larger castings – where you don't want the mold to flex or sag,
• Molds for frequent and repeated use – serial production of the same items,
• applications where strength and precise shape are prioritized over extreme flexibility.

ASF 40SH is still partially flexible, but significantly stiffer than softer variants (10SH, 20SH). Therefore, it is not ideal for very deep undercuts or extremely intricate models where the mold needs to be significantly "twisted" out.

How to work with ASF 40SH?

• prepare your model (master) – clean, dry, degreased, dust-free,
• measure components A and B in a ratio of 100 : 100 by weight,
• mix thoroughly, including the sides and bottom of the container, to ensure a homogeneous mixture,
• pour slowly and from a height in a thin stream, which limits the formation of bubbles,
• allow to cure at room temperature (approx. 23 °C) – usually 6–12 hours depending on the layer thickness.

For maximum clean molds (especially for thicker blocks), it is ideal to use a vacuum chamber or pressure pot. For regular hobby use and smaller molds, it is possible to work without them, just with careful mixing and pouring.

Compatibility and practical tips

• platinum (addition) silicones are sensitive to contact with certain materials (e.g. sulfur rubbers, some plasticines, fresh acrylates) – they can slow down or stop curing,
• for unknown substrates, we always recommend doing a small test on a piece of material,
• after demolding, let the newly made mold 'rest' for several hours.

Platinum ASF 40SH mold making silicone is the ideal choice if you are looking for a strong, stable, and durable mold for casting epoxy resin – for example, for coasters, decorative panels, flat boards, or molds used more frequently in the workshop.