what kind of epoxy?

[HypnoticCure 10+ year member]

Exactly, westsystem is quite expensive but its also top of the line stuff. I use it on boat and pwc repair. I use it for glassing, fillers and many other applications. Just be sure to mix it correctly and use gloves. It isnt toxic smelling or anything. Use a mask if mixing a filler into it though. For what your talking about doing the low density filler(red powder) would be just fine. West marine often offers a free video with purchase of #105. If they have the video it is a good watch if you plan on future repair or modification of plastics, fiberglass or smc projects.