Cabosil M5 (formally Aerosil 200) is used to thicken up resins and is commonly called glue powder. Typically used in the marine industry for projects that are below or above the waterline due to providing excellent watertight properties. It is made from hydrophilic fumed silica with a surface area of 200m2/g. Also has anti-sagging properties that can help keep shape while the project is hardening.
