BN Cera Patch is now sold in a metal 32 oz. can. It is a ceramic patching material that can be filled into any fissure, crack or defect in refractory materials to achieve non-wetting with molten aluminum. This premium repair product is based on Boron Nitride and is completely free of Refractory Ceramic Fiber (RCF). BN Cera Patch is engineered to expand to fill damaged areas and does not sinter, shrink or crack with use.