Bostik Sealant All Weather Black is a versatile repair mastic suitable for sealing small joints and cracks between stone, concrete, and metal. It's also great for sealing leaks in gutters and can be used as a steel construction mastic for joint constructions in aluminium. This sealant can be used as a roofing sealant to bond and seal as an emergency repair, and it's effective in rain or puddles, sealing leaks immediately. It can be used on various materials such as lead, glass, wood, metals, and stone. Once dry, it can be painted over after 24 hours. For external use only, this sealant comes in a 300ml size.