Making moulds for grill parts. Anyone do it?

[bull]

Typically the lower corners that almost always get snapped off. I've heard of a few people using some sort of moulding clay to make moulds of commonly damaged portions of good headlight surrounds and filling them with (I assume) epoxy to make corners to repair others that have missing corners. Has anyone here done this? If so my main question is what type of moulding material do you use and what type of material do you use to fill it?

[areibel]

I've messed around with RTV rubber molds and urethane casting plastics from here-
http://www.smooth-on.com/

There are different grades of mold rubber (basically how "squishy it is), but the harder ones have their own problems.  Same with the plastics, the basics are just a 50/50 mix and cure pretty rapidly, but the strength might not be there fo an exterior piece.  The better plastics are pretty sturdy but a lot harder to use.  There's a lot of info on their website, or this place has an excellent DVD of the process-
http://www.freemansupply.com/

They sell supplies too, but I haven't used theirs.  I've wondered if the grille could be done like this, but it would be a huge mold!  A plug for a repair though, that might work, even if you have to reinforce the repair plastic with a little fiberglass mesh.

[bull]

Yeah, I doubt something like this would work on such a large scale but small castings of the commonly broken plastic pieces would be nice to have.

Thanks for the info.

[bill440rt]

I've just made a backing out of metal foil tape applied on the top side, and applying a plastic repair material such as SEM on the back side. Once hardened, peel off the tape, scuff, and apply more filler material to the top side. Sand both sides to shape and smooth. Prime, paint. Done.

[bull]

  I guess the best thing would be to have a couple of good surrounds on hand to use as templates. I sort of wanted to rebuild these things on the side after I get mine done.