Gorilla Waterproof Caulk & Seal 100% Silicone Sealant* seals out water, air and moisture and is great for kitchen, bath, window, doors, auto, marine plumbing, gutters and more! Ready for water exposure in just 30 minutes, this waterproof sealant is mold & mildew resistant. This silicone sealant won't yellow, shrink or crack over time! **Note: Do not use on wet, damp, frozen or contaminated surfaces. Not paintable. Not for use in underwater applications, aquariums, on brick, masonry, cementitious materials or on metals sensitive to corrosion including brass & galvanized metals. For general auto/marine applications – not for under hood or direct gasoline exposure. TO OPEN: Cut nozzle at 45° angle to desired bead size. Puncture inner foil seal. TO USE: All surfaces should be clean and free of dirt, grease, oil and old sealant. For gaps larger than ½ inch use backer rod. Best if applied above 40°F (5°C). 1) Insert into cartridge gun. 2) Apply sealant, pushing bead ahead of nozzle. 3) Smooth bead immediately after application, before skin forms. 30 MINUTE RAIN/SHOWER READY: Can be exposed to water in as little as 30 minutes based on a 3/16” bead at 70°F (21°C) and 50% humidity. Otherwise, wait 24 hrs. STORAGE: Replace cap tightly to prevent material from curing. Store in cool, dry location. To re-use nozzle, remove sealant from nozzle once cured. CLEAN-UP: Wipe wet sealant off project immediately with a dry cloth. Isopropyl alcohol may be used according to solvent manufacturer’s instructions. Click on the Gorilla link at the top of the page to see more Gorilla Tough products.