: John,

: . . What if you wiped it
: up in thickened epoxy, and maybe some glass fibers added for strength,...

I think this might be a better idea than Bondo. Mixing up a thickend epoxy should give you something more durable and compatible. If you can get microballoons you'll have a lightweight filler material. Otherwise, try mixing a sample of epoxy with finely chopped foamed styrene (the insulating boards sold under the name of Styrofoam would be suitable, as would similar products) How you would turn this stuff into a fine powder may be a problem, but one you should be able to solve. One ides: feed the edge of a sheet of foamed plastic against a belt sander loaded with coarse grit sanding belt.

Add some glass cloth threads to the mix for strength and to resist cracking. Cut a strip of glass cloth an inch wide and pull out the long pieces so you get a pile of 1 inch pieces of glass fibers.

You want a material that is mostly light weight filler and that is held together with a minimum of resin. When you get the shape right, cover the thing with layers of glss cloth and resin for added strength.

PGJ