PLATINUM ASF 20SH 1 kg silicone for mold making

Product detailed description

Platinum silicone ASF 20SH for stronger resin molds

ASF 20SH is a platinum (addition) cured silicone for making molds that need to withstand a bit more – larger castings, wider coasters, thicker mold walls, or more frequent use. Compared to softer silicones (e.g., 10SH), it offers higher hardness and better dimensional stability, yet the molds remain flexible enough for easy demolding.

The silicone is mainly intended for casting epoxy resin, or other materials compatible with platinum silicone (selected polyester or polyurethane systems). Thanks to its low shrinkage during curing, it maintains dimensions and transfers surface texture very well.

What is ASF 20SH ideal for?

• Molds for coasters and small trays – round, square, hexagonal, or organic shapes,
• Molds for decorations and panels – relief plates, decorative tiles, flat motifs,
• Reusable molds – where you'll appreciate higher strength and longer mold life,
• Molds for casting from epoxy resin and other suitable materials.

A hardness of approx. 20 Shore A means the silicone is still flexible, but less 'rubbery' than soft variants – this helps maintain straight edges, a flat mold bottom, and overall shape even during handling or when pouring a larger volume of resin.

How is ASF 20SH used?

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

For very clean molds and minimal bubbles, it is ideal to use a vacuum chamber or pressure pot, but for most hobby and craft projects, you can work without them.

Important notice – material compatibility

• platinum (addition) silicones are sensitive to contact with certain materials (e.g. sulfur rubbers, some plasticines, fresh acrylates), which can slow down or completely stop curing,
• for unknown substrates, we always recommend doing a small test on a piece of material,
• let the new mold "rest" for a few hours to "rest" after removing it from the molding frame before the first resin casting.

Silicone for mold making PLATINUM ASF 20SH is an excellent choice for anyone who wants more robust and durable molds for epoxy resin – for example, for coasters, decorative panels, or repeated serial production of their own products.