Mould Maker Silicone Rubber 2x 500 gram tubs to create moulds

Two tubs of 500 grams of silicone rubber that gets combined to make 1 kg of silicone rubber. Manufactured March 2025.

Room temperature curing silicone rubber. Suitable for white metal and resin casting. Shore hardness 60 which much harder than usual silicone rubber, so your model does not get distorted, when you are clamping the mould, while pouring the metal or resin.  Mixing ratio 1 :1 for easy and accurate mixing. 
Working time 30-50minutes. Curing time 10h.

The silicone rubber and modelling clay is NON-toxic.

Material Safety Data Sheet for Silicone Rubber Tub A and Tub B. (PDFs)

Download a short tutorial in a PDF on making a mould using this material.

We made a series of videos to explain the entire process in detail. 

Short summery of use:

• After preparing the modelling clay base with a wall of more modelling clay properly (see videos), measure the mould to find out the amount of silicone needed.
• Increase the amount by at least 15% to account for not being able to remove 100% of the silicone from the tub when pouring.
• Mix for 2 minutes per 100 grams approximately. 50% per tub. Do not contaminate either tub with the other tub contents, so avoid using the same knife.
• Allow the mix to stand for 10 to 15 minutes to allow air bubbles to escape.
• Pour the rubber at one end of the walled base only and allow the flow of silicone to naturally travel over the entire surface of the base.
• After the entire base is covered you can empty the remaining rubber in your mix into the base to top it up.
• Leave overnight to cure at room temperature (20 degrees Celsius). Put in a fridge for 2 hours to harden the modelling clay to aid removal.
• Remove the modelling clay wall carefully then peel the base from the new mould half.
• Transfer the tool and ingate to the new mould half and prepare for the second half pouring the same way you did the first.
• After pouring the second half, leave overnight again to cure. Put in fridge again to harden modelling clay. Remove the walls and separate the moulds. Remove the master and ingate.
• Clean the moulds of all modelling clay and trim the moulds up, as seen in the videos provided.