Dryout Instructions

General Dry Out Instructions for WAM® Castables, Gun Mixes and Shotcrete Mixes. This Method is Also Applicable to WAM® AL II and Variants as Noted

 

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Prior to beginning any dry out process, calcium aluminate cement bonded products must be properly cured. Ambient temperatures during curing must be above 50 °F. Surfaces must be sealed to prevent water loss during the curing process. An appropriate amount of time must be allowed for the curing process to develop bond strength. 24 hours is common, although stripping of forms may be allowable after a shorter period of time.

 

Dry out should proceed from ambient temperatures at a steady rate of temperature increase dependent upon lining thickness. In the event that multi layer linings are being dried, the total lining thickness will guide the rate of increase. No hold periods are recommended.

 

Linings intended for contact with molten metal must be dried to a minimum temperature of 800 °F all the way through to the cold face of the working lining. For multi layer linings, this means the interface of the first and second layer of the installation. Note: To avoid uneven heating that may result from these products’ insulating properties the maximum recommended dry out temperature for WAM® AL II and micro-porous variants is 1300 °F.

 

As a guideline, calcium aluminate cements will release about 75% of the water contained in the hydraulic bond upon exposure to 800 °F, and will release 100% of the water that is part of the bond after exposure to 1150 °F. Because refractory linings have an insulating quality, cold face temperatures will always lag hot face temperatures, and the water release at the cold face will therefore lag the water release at the hot face.