An improved method and apparatus for imparting a smooth surface to a gypsum
fiber panels. The method involves imparting energy to the surface of the
slurry as the slurry is dewatered just prior to rehydration. The apparatus
used to impart the energy is an air lance including an air source such as
a blower, a distribution manifold and a plurality of nozzles to direct the
flow of air at the surface of the slurry. In operation, the air lance
directs a flow of air against the surface of the slurry. The flow disrupts
the slurry to a fraction of its total depth, thus dispersing clumps or
flocs of crystals in the depth that would give the surface of the finished
panel a rough surface if they were allowed to remain.
