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