Question about fake rocks and rock hides

[ladyjustice33]

Okay......I went to an expo and one table was selling rock backgrounds, rock hides, and rock water bowls, etc. When you pick them up you realize they are fake, they are feather light. Anyone have any idea what they might be made of? Hubby said plastic probably, but I don't know. I'd like to make my own and have been looking online for ideas. Anyone on here make their own, I would appreciate any tips and ideas!!

Thanks,
Kat

[Quack]

They could've been made from some kind of foam and mortar, such as this:
my method of building fake / faux rocks - Vivarium Forums (http://www.vivariumforum.com/community/terra-construction/3621-my-method-building-fake-faux-rocks.html) They wouldn't be extremely light, but much lighter than an actual rock, as long as he didn't put too much concrete on it.

[ladyjustice33]

Wow thanks!! That waterfall looked amazing!

[knox]

They are probably some type of polymer resin, poured into molds to make the rocks and caves.

[Quack]

i didn't think of polymer:)

and that link isn't mine, so i didn't make that, just to clarify because i didn't think about any confusions that would cause when i posted it.:yes: I've made things using method similar to that, but not anything that good:no:

[ladyjustice33]

Thanks guys! I think I'm gonna try the styrofoam and grout method......we'll see how it turns out!!