G4 Damp Seal is a polyurethane that hardens with moisture. It is browny tranclucent in colour. G4 provides a tough, highly durable non-porous seal on most porous materials.
Since G4 is hardened by moisture it can be applied to surfaces that contain some moisture although any surface onto which G4 is applied must be dry enough to be porous. This enables the first coat to penetrate and obtain a mechanical grip. G4 can be used in poor application conditions with temperatures down to 0°C and in areas of relative high humidity.
G4 seals damp out of concrete, brick, stone and wood. The coating is hard wearing but flexible and resistant to many acids and alkalis in normal concentrations. It withstands boiling water. While G4 is an excellent sealant it does not have any filling or bridging properties. It will not fill cracks or holes.
Sealing with G4 is easy and quick, three coats can be applied in a day. G4 is browny translucent in colour and is effected by UV light. Therefore it is for internal use unless top coated to protect it from UV light
G4 is recommended by all the major polyester resin manufactures as a bonding primer between polyester resin (G.R.P.) and materials such as wood, metal and concrete. It is widely used by roofing contractors when applying glassfibre roofs. Brush on a coat of G4 to the clean base substrate. As soon as it is finger tacky but within 2 hours apply the polyester resin and glassfibre (G.R.P) laminate.