Supporting Vacuum Formed Terrain Pieces?

[The Gonk]

I'm current working on GW's moonscape and blastscape pieces.  They're not too flimsy, but if there's some easy way to support them, I want to do it before I spend the time painting them.  I thought about filling them with plaster of paris, but worried about shrinkage or it dropping loose and rattling around once it's finished.  Anybody done this before, or have any other ideas?  Thanks!

[Supercollider]

How about that expanding insulation foam?  Would be much lighter than plaster?

[kidterminal]

You could strenghten the model its self by coating it with wood glue or super glue.

[Ramshackle_Curtis]

Resin. Use some cheap resin(polyester, fiberglass resin), mixed with cooking flour. That will make it sticky and thick, so just coat the underside of the terrain and it will be light and strong.

Either that or pva mixed with sand. Actually, this would be a far easier way of doing it, plus pva/sand mix has a good amount of flex in it. Dont fill the back of the piece, just give it a good thick pasting of the stuff.

[Aaron]

How about that expanding insulation foam?  Would be much lighter than plaster?

The staff at the local game shop did exactly that. It made them plenty strong, but still light. An added bonus is that they don't slide around at all on the tables now.

[HerbyF]

I just cover mine with several thick coats of latex paint. Just slather it on real thick on the underside. You can also add a little sand or sawdust to help thicken it up more.

[The Gonk]

I've got some pictures of my Moonscape pieces up, plus a link to Drunken Samurai's blog and how he used insulating foam on his.