Platinum Cured Silicone Rubber (R15 / R25 / R35)

Description

Platinum Cured Silicone Rubber: Two-Part Mould-Making Silicone

Make flexible, detailed moulds in one easy step. This two-part, platinum-cured (addition-cure) silicone mixes 1A : 1B, cures to a translucent rubber and copies fine surface detail with very low shrinkage, so your moulds stay accurate and last through many castings.

Choose your grade

What can you make with it?

Photos: Feliphe Schiarolli, Pavel Subbotin, Eric Prouzet, Jose Antonio Rodriguez Davia and Azeez Maree on Unsplash. Examples of the uses shown, not products made with this item.

Key features

• Easy 1:1 mix by weight, with no small catalyst quantity to measure
• Translucent: see the master inside the mould, cut a clean parting line and spot trapped air
• Low shrinkage, high detail: reproduces fine textures and layer lines faithfully
• Durable and reusable: platinum cure gives a clean, stable rubber with no by-products
• Three grades so you can match the softness to the part

How to use

1. Prepare a clean, dry master and build a mould box around it. Seal porous masters first.
2. Weigh and mix equal parts of A and B and stir for 2 to 3 minutes, scraping the sides and bottom of the container.
3. Remove air in a vacuum chamber if you have one, or pour in a thin stream from a height to limit bubbles.
4. For over the master, let it cure fully, then demould and cast.

Important: avoid cure inhibition

Platinum silicone can fail to cure if it touches sulphur, tin-cure silicone, latex, some modelling clays or some 3D-printing resins. Always test a small area first, and fully wash and UV post-cure resin prints before moulding them. Use clean, dedicated mixing tools and nitrile gloves, not latex.

Frequently asked questions

Which grade should I pick?
Choose R15 for intricate parts with undercuts, R25 if you are unsure, and R35 when you need a firmer mould for larger or flatter shapes.

What is the mix ratio?
1A : 1B by weight. Always follow the supplied technical information for your batch.

Can I make food moulds?
Platinum silicone is the usual choice for food moulds, but please contact us to confirm the food-grade status of your batch before food contact.

Can I use it with 3D-printed parts?
Yes. FDM and resin prints both work as masters. Wash and fully cure resin prints, and test for inhibition first.

Which sizes are available?
2 kg kit and 10 kg kit (Part A + Part B), in R15, R25 and R35.