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 Is this product good for adhering to wood. I'm looking to waterproof a 1/2 whiskey barrel for ponding ? How long does Liquid Rubber Waterproof Sealant take to cure? How come it feels tacky? Is it cured? Can Waterproof Sealant be put on tarred surfaces? How do I cover gaps and cracks? Comments 0 comments Article is closed for comments.