http://www.sailrite.com/Trimmable-Butyl-Tape-3-4-Bedding-Deck-Hardware-Sealant Butyl Tape is an off-white, non-hardening elastic butyl based material which is great for bedding applications on boats. Use this #180 Trimmable Butyl Tape to seal out water when drilling screw holes for bimini and dodger frame fittings, snaps, awning track installation, stanchions and much more. Butyl tape provides excellent sealing adhesion to any type of metal, wood, concrete, glass, plastics, fiberglass and porous surfaces. Can be used under moldings; around windows, doors and vents, butyl can be trimmed easily with any stiff, pointed non-scratching object. #180 butyl tape increases in adhesion with age after it is applied. It can be pressed and formed to obtain a water and air tight seal. Recommended temperatures for application are between -30F and 200F (for best results apply at room temperature on dry materials).