Milled Fiber, I am not having it handy but I spoke to West Marine in local and they said, they have "Marine Structural Filler" and the description is as follows,

Great for fiberglass and sheet metal ding repairs
Fiberglass filler with long strand reinforcing fibers for fiberglass and sheet metal repairs. Water-resistant. Hardener included. Great for quick and easy ding repair on fibergalss surfboards, sailboards, canoes and runabouts.

Formulation: Polyester putty
Recommended Usage: Fiberglass and sheet metal repairs
Color: White
Quantity: Quart

Is this something I can use in place of milled fiber??