Cab-o-sil - Colloidal Silica Epoxy Filler - 8 OuncenThicken epoxy mixtures to create a non-sagging mixture that hardens to a strong joint filler.nThis is a 8 liquid ounce maximum container of ready to use powder.nPre-mix epoxy then mix in powder as needed to desired consistency.nCab-o-sil, or Colloidal Silica is used to thicken epoxy mixtures to create a non-sagging mixture that hardens to a strong joint filler. This is a 8 liquid ounce maximum container of ready to use powder.