ACC Silicones RTV MM918 : MM922 : MM928 Silicone Rubber. The new 900 series, giving maximum mould life and ease of use. A Condensation cure silicone with 2 stock catalysts, fast and slow, allowing for varied demould times. Compatible with Polyester, Epoxy and Polyurethane Resin as well as all British Gypsum Plasters and Jesmonite. Shelf life of the base silicone is at least 6 months from purchase and up to one year.

This quality silicone has a variation of tensile strengths of  and excellent elongation at break . There are a large variety of  Shore A Hardnesses availble from 16° to 27°, all with excellent tear strengths. This is an excellent all round moulding rubber for many difficult jobs. Select the soft grade if you require better viscosity and are dealing with deep undercuts or difficult pultrusions. Soft also makes a good skin mould supported via a jacket.

Medium is a good all rounder and if unsure of hardness to take, is the best first choice. It is marginally harder than soft but resists mould slump more. This is our biggest selling rubber!

Think about going for the hard compound if you have very deep undercuts or large pultrusions and are making a sectional mould, this will help eliminate slump. The Hard grade also makes a good non slumping skin mould.

Kit contains 4760g of Silicone Base and 240g of  Catalyst forming a complete 5kg kit. For fastor slow catalyst select the option for the small additional charge (extra charge only on 21kg kit).

Please view the Techincal Table on the category main page for technical information : RTV Mouldmaking Silicone