Material Notes:
ZRCI AL-HARD Rigidizer/Hardener is used to increase the hardness of ZRCI Refractory Sheet products. AL-HARD is comprised of Aluminum Oxide and Phosphoric Acid in a water base. Refractory Sheet products treated with AL-HARD are ready for use after drying. When a chemical bond forms it hardens the fibrous material. The degree of hardening depends on the amount of AL-HARD used. AL-HARD is non-flammable and is not affected by freezing. It can be applied by immersing, spraying, brushing or sponging on many of ZRCI`s Refractory Sheet products.Information provided by ZIRCAR Refractory Composites, Inc. (ZRCI)