In article ,
says...
2 parts by weight Alumina Hydrate.
1 PBW Kaolin.
Mix with water to a thin cream and stir very frequently; it settles at the
speed of light!

Steve


you can also add 4 table spoons of gum arabic per gallon (one per quart)
or 1/2 PBW ground clay (bentonite(fullers earth)) Cat litter to slow
the settling