Can Waterproof Sealant be applied to Styrofoam? Yes, all the products are water based containing no solvents or VOC's. It can be applied to Styrofoam. Related articles Can Waterproof Sealant be put on tarred surfaces? What is Liquid Rubber MetalSafe Sealant used for? How do I cover gaps and cracks? Can the Earlex Sprayer spray the Original Black Waterproof Sealant? Will sun have an effect on the Liquid Rubber Waterproof Sealant? Comments 0 comments Please sign in to leave a comment.