370 Silicone Rubber is a soft moulding rubber from Sylmasta which has good flexibility and high tear strength for creating moulds with deep undercuts

Moulding Rubber

Sylmasta Silicone Moulding Rubbers are used to create flexible, highly detailed, reusable rubber moulds for resin casting by model makers, kit builders and industrial users.

All Sylmasta Moulding Rubbers have extremely high tear strength. They are made to the highest standards to produce moulds of all sizes and have been trusted by professional kit builders and industrial users for years for their high detail and repeatability.

Once a mould has been taken from the master, it can be used again and again to pour multiple castings using Sylmasta PU Casting Resins.

Three grades of standard Sylmasta Moulding Rubber are available. Graade 370 is the softest grade which is used for creating moulds when there are deep undercuts.

Grade 380 is slightly stiffer for greater dimensional stability. Grade 390 is the stiffest grade and is used for larger moulds.

There are two additional grades of Sylmasta Moulding Rubber. Grade 400 which is for the casting of clear polyurethane resins and is certified as food safe, allowing it to be used to cast chocolate, icing, ice cubes and many other foods.

Grade 375 is a high temperature grade of Sylmasta Moulding Rubber used for the casting of white metals. It has a service temperature of 250°C and high chemical resistance.

For the making of split moulds, Sylmasta Mould Release Agent prevents the silicone moulding rubber from sticking to itself.

You can purchase both Moulding Rubber and Casting Resin together in a Sylmasta Casting Kit, containing all the products and equipment needed to begin resin casting.


Sylmasta Silicone Moulding Rubbers and Release Agent
Grade 370 is the softest grade of Sylmasta Silicone Moulding Rubber used for creating moulds with deep undercuts
Grade 380 is the medium, all-purpose grade of Sylmasta Silicone Rubber. It is stiffer than Grade 370 for better dimensional stability
Grade 390 is the stiffest grade of Sylmasta Silicone Moulding Rubber with its high dimensional stability making it ideal for larger moulds
Grade 375 is a high temperature grade of moulding rubber suitable for the casting of white metals
Grade 400 is for the casting of clear polyurethane resins to create water clear casts. It is certified food safe
Mould Release Agent is used to prevent the silicone moulding rubber from sticking to itself during the making of split moulds

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