SealBoss ® 1570 Water-Stop-Foam is a very flexible hydrophobic water / hydro activated water cut-off grout and foam seal grout based on a MDI (methylene-diphenylisocyanate) polyurethane. The resin is 100% solvent free and 100% solids. The gel-time of the product is adjustable by the mandatory adding of a certain percentage of 15x Accelerator. Upon contact with water 1570 Water-Stop-Foam reacts to a very flexible foam while expanding its volume 6 to 25 times. The cured material is flexible in its elongation and compression properties, and is of a constant volume. Since water is not a component of the foam structure, the cured material is essentially not effected by water or dryness. The reacted material does not shrink or swell.