Zircar Refractory Composites
The AL-HARD rigidizer/hardener is used to increase the hardness of Zircar refractory sheet products. It consists of aluminum oxide and phosphoric acid in a water base. Refractory sheet products treated with AL-HARD are ready to 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. It is nonflammable and is not affected by freezing. It can be applied by immersing, spraying, brushing or sponging on many of the refractory sheet products.
September 10, 2002