Master Bond MASTERSIL 800 and 801 compounds are ready-to-use one component high performance non-corrosive silicone elastomer compounds for bonding, sealing, protective coatings and formed-in-place gaskets with outstanding heat resistance up to 300°C (572°F). They are black non-corrosive compounds which cure readily at ambient temperatures to flexible rubbery solids with excellent resistance to thermal shock as well as mechanical shocks and vibrations. MASTER SIL 800 and is a self leveling, free flowing, low viscosity material that allows filling minute crevices and voids in sealing and potting applications. It becomes tack free in approximately 20 minutes at ambient temperatures. MASTER SIL 800 and MASTER SIL 801 employ a novel non-corrosive cure system which permits their employment in applications in section thicknesses up to 6mm (1/4 inch). used in thicknesses greater than this they may never cure fully. Master Bond recommends the use of two (2) component silicones for applications with section thicknesses greater than 6mm (1/4 inch).

The cured Master Bond MASTER SIL 800 and 801 compounds have excellent adhesion to most common substrates including many metals, glass, ceramics, most woods and plastics without the aid of a primer. For maximum adhesion Master Bond recommends the employment of specific silicone primers. Consult Master Bond for details regarding problem substrates. All surfaces to be bonded or sealed should be thoroughly cleaned with a suitable solvent such as naphta, MEK or 1,1,1 trichloroethane to remove dirt, oil or grease. The surfaces should be wiped dry before applying the silicone adhesive sealants. All solvents should be considered toxic an should only be sued in well ventilated areas. Exposure to high solvent vapor concentrations must be avoided. Where flammable solvents are used, storage, mixing and use must be in ventilated areas away from heat, sparks, open flames and other sources of ignition.

The curing process commences with the formation of a skin on the exposed surface of the material and proceeds inward through the material. At 75°F and 50% RH, a tack free film of MASTER SIL 800 is formed within 20 minutes or so. All tooling should be completed within the first 5 to 10 minutes and is no longer practical once a tack free skin has formed. Should masking tape be sued to mask off an area, it too should be removed before such skin formation occurs. High temperatures and high humidity accelerates this curing process. usually sufficient bond strength will be obtained within 12-24 hours at ambient temperatures. When fully cured the adhesive strength of the bond will exceed the cohesive strength of the silicone rubber itself. Clean up and removal should be effected before curing with solvents such as naphta, MEK or 1,1,1 trichloroethane. Refer to the solvent use warnings in the previous paragraph. The cured MASTER SIL 800 and 801 products feature excellent retention of the physical strength properties even after prolonged exposure to temperatures as high as 300°C (572°F) and resist weathering, moisture, ozone an temperature extremes. Shelf life of uncured materials is 6 months from date of manufacture.