This amazing glass sealer is permanently elastic and will not crack or wither under UV rays; it is resistant to water, caustic washing solutions and atmospheric influences. Use between rubber profiles and body joints when fitting front and rear windscreens. The Black Windscreen Sealer is also perfect for fitting sunroofs. Will not attack chrome, paint or rubber. Tack Free Time at 20º C/65 % RH: 24 hours Arbomast Autograde forms a skin after approximately 14 days depending upon atmospheric conditions. A  Caulking Gun  is required to apply.