... nature and curious property of swelling in water.Characters1 Good waterproof capacity, sodium bentonite can form a gel layer which does ... well.3. Good water-keeping and self-fix capacity4. Permanent waterproof capacity, sodium bentonite is natural inorganic mineral material, there is ... for ground tank farms, dams, canals, ponds, rivers and lakes. waterproof material (waterproof blanket) GCL