Zircoat should be applied on clean surfaces only. Old refractory surfaces must be thoroughly cleaned with a scraper or wire brush, removing all loose pieces and particles. Any glossy surface should be thoroughly roughened with an abrasive disc. Cracks and holes should be cleaned and then filled with a thick Zircoat paste. Before applying Zircoat, the surfaces of refractories, castables etc. may be dampened with water.
Mixing : Thoroughly dry mix the Zircoat powder, add clean tap water to it to form a smooth paste of toothpaste like consistency. Add required quantity of water to adjust the consistency of the mix to suit brushing, trowelling or spraying applications.
Excess water will lead to high shrinkage, crack development & loss in mechanical strength.
The pot life of the good mix is for around 8-10 hours at room temperature. Therefore consume the mix during this period.
Application : Coat the surface by brush, spray or troweling to a thickness of 1-3 mm.
If required, further coats can be repeated to increase the coating thickness. Zircoat is also used as a cementing mortar for building and laying of new refractory brick lining.
Drying : Allow each coat to dry thoroughly at ambient temperature. (For 1-3 mm thick coats 24 hour; for thicker coats & mortar masses 24-72 hours).
Initial Firing : Raise temperature slowly at the rate of 20OC - 25OC / hour up to 600OC. Thereafter at usual rate to bonding temperature.
MINIMUM BONDING TEMPERATURE |
Zircoat - HT : 1500OC |
Zircoat - M : 750OC |