What temperature can I apply Liquid Rubber MetalSafe Sealant? Liquid Rubber Waterproof MetalSafe should be applied above 5°C (41°F). Avoid hot, direct sunlight applications as well. Related articles What if I don't want black as my final color? What should I use to clean up? How long does Liquid Rubber MetalSafe Sealant take to cure? Can I use RV Roof Coating on a Metal Trailer Roof? Comments 0 comments Please sign in to leave a comment.