Yep, same stuff. Also sold as Cab-o-Sil or Cabosil. It is a thixotropic (non-sag) agent that you can add to epoxy to make it thicker and resistant to running out of a joint. It can also help make an epoxied joint stronger because it keeps the joint halves separated slightly so they're not "resin-starved".

Works great. It's super fine stuff--you probably don't want to breathe the stuff in, though.

Does anyone know if silica fume would cause silicosis?

Shawn

> While looking over literature from our fiberglass supplier at work, I came
> across the item "fumed silica." Does anybody know if this is the
> same as colloidal silica? Does anybody know its use? Thanks, Tom