SikaflexÂ® Crystal Clear is a 1-component, solvent-free, multipurpose adhesive and sealant with a crystal clear appearance. It may be used in architectural applications and DIY projects, including both interior and exterior sealing and bonding jobs. This product is 100% crystal clear / transparent and will create a durable and waterproof seal. It may be painted after full cure and has an excellent workability. It is ideal for areas exposed to high moisture levels, such as bathrooms, kitchens, etc.