The black surface turns brown when wet? This is normal on the surface, the waterproofing is not affected. Related articles Will sun have an effect on the Liquid Rubber Waterproof Sealant? What if I don't want black as my final color? How do I cover gaps and cracks? What if I see blisters? Is Liquid Rubber Waterproof Sealant environmentally friendly? Comments 0 comments Please sign in to leave a comment.