Able Plastics
The satisfactory service life of any plastic refractory product is
determined, in part, by proper installation procedures, and by carefully
following correct curing and firing schedules. The following are suggested
steps to be taken into consideration.
Storage
Store in a location protected from the weather. Keep out of direct
sunlight. Keep in a cool location during the summer. Avoid freezing in the
winter. Rotate stock.
Installation
Installation by the air-ramming method is recommended, to achieve higher
density, and to eliminate laminations. A rammer with a flat-type head is
recommended.
Use rigid forms for arches. Forms for walls and special contours are
optional.
Proper anchoring and support of monolithic sections is very important.
Immediately after installation and prior to firing, we recommend covering
all surfaces with a thin layer of plastic (any type) to prevent surface
drying and cracking. This layer of plastic should be removed just prior to
firing.
In patching, clean surface thoroughly, and, for best results, apply a
coating of high temperature bonding mortar before installing the plastic
refractories.
Control joints are essential to prevent necessary random cracking.
Forced drying air-setting plastic refractories is desirable to prevent
formation of an outer skin that can seal in the moisture. Maintain a
temperature not over 2500F until all free moisture is completely
removed.
Drying and curing should be started as soon as possible after the
installation is completed. The following curing procedures are recommended
for best results. Bring the temperature to 2250F and hold for
twenty-four (24) hours. Then at a rate of 250F per hour, raise
the temperature to 6000F and hold for twelve (12) hours. Then at
a rate of 500F per hour, raise the temperature to 12000F
and hold for twelve ('2) hours. Then at a rate of 500F per hour,
raise to operating temperature. (minimum 16000F). Hold at this
temperature until the heat balance through the material is established to
obtain the ultimate ceramic bond. If excessive steaming occurs anytime
during the procedure, hold firing rate until steaming subsides. Heat-up is
to be continuous and uninterrupted. All temperatures are to be measured at
the surface face of the refractory. Cooling should not exceed a rate of 1000F
per hour.
