Two tubs of 500 grams of silicone rubber that gets combined to make 1 kg of silicone rubber.
Room temperature curing silicone rubber RTV. Suitable for white metal casting. Shore hardness 60. Mixing ratio 1:1.
Operating time 30-50m. Curing time 12 hours.
UPDATE: Feb 2024 NEW Silicone Rubber is even better and smoother than previous silicone.
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.
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.
