CABOSIL THICKENING AGENT – Fumed Silica (aka Cabosil) is an extremely fine powder used to thicken virtually every liquid material. It is typically used to thicken resin, paint, dyes, and even water. It is great for making fillet putty, thickening epoxy for a better glue consistency, and for use below the waterline. Resin mixed with Fumed Silica (Cabosil) is an ideal product for repairing the blisters that are so common on fiberglass boats. For a given weight or volume of Cabosil, it has an extremely large amount of surface area. Resin, being a petrochemical with an oily feel, tends to drain off a vertical surface; by adding Fumed Silica, the resin can be made to stay in place on a vertical surface. Fumed silica is also mixed with Milled Fiber for structural putty and or microspheres (Q-Cells) for sandable putty.
It is used in approximately a 1:1 ratio to the mixed resin by volume. This will provide a consistency similar to vaseline. You may use more or less to suit your application. It adds a milky white color to the resin. Product is sold by the quart and gallon.
To view the SDS for Fumed Silica: CLICK HERE