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 How long does Liquid Rubber Waterproof Sealant take to cure? Is this product good for adhering to wood. I'm looking to waterproof a 1/2 whiskey barrel for ponding ? What if I see blisters? How come it feels tacky? Is it cured? Comments 0 comments Article is closed for comments.