Light-weight, fumed silica. Used as a thickener
for polyester and epoxy resins. The most effective additive
for thickening resins, thixotropic powder thickens putties
and glues and, most importantly, helps prevent them from running
and sagging on vertical and overhead surfaces. Always added
to System Three Epoxy Resin (to about a ketchup consistency)
when making epoxy glue to prevent running from joints.