Oatey 25410 Hercules 1-Gallon Roof and Flashing Sealant Long-lasting sealant. No separation; no stirring time; no objectionable odor. Forms durable, flexible, weatherproof coating. Can be applied on cold or wet surfaces. Long-lasting sealant Forms durable, flexible, weatherproof coating Can be applied on cold or wet surfaces. No separation; no stirring time; no objectionable odor