Strengthens weak ,thin nails Rebuild helps weak, thin, soft, or peeling nails. This unique protein formulation seals the layers of the nail together. What it does: Easy to apply; Crack resistant; Dries quickly; Exciting, solid, clean color with a semi-gloss finish.; What else you need to know: With each application, Rebuild reinforces and thickens nails providing durability while promoting strength and flexibility.