Rayston Flex 3040 Mastic

This is a superb low modulus polyurethane mastic sealant which adheres to glass, masonry, and wood etc. It is great for filling in cracks in Koi Fish Ponds where the cement/screed has shrunk with the curing process. It is light grey in colour.

It is applied using a typical extrusion gun available from every Builders Merchant.