I've been researching this for ages and have yet to start any experiments of my own, though I would like to soon. My concern has always been durability and longevity. I've noticed a lot of users here have done some very nice work with their enclosures and I wonder if anybody could share tips or techniques that have proven to work well? Building up the form is no problem, as I'm pretty familiar with these methods but what do you use for the surface and for colour/texture? I'm hesitant to use fibreglass resin, but that may be my only option. I've tried contacting the folks at Zoopoxy for ages with no response, so I'm running out of ideas and I think it's time to just try putting something together.
Thank you in advance for any responses!

JonK

check out this link. the post is 28 pages long and i do suggest going through all 28 pages as there is some VERY useful information about making amazing fake rocks.

http://www.dendroboard.com/forum/parts-construction/16605-making-fake-rocks.html

Hi Jon,
I bet there will be some words completely wrong. Sorry about the english.
I use PU-foam or styropor (the white queecki stuff) but not togheter, otherwise i get cracks.
Cover it with cement whitch is used to glue bath tiles, here you can already ad the colour.
Maybe you will even find something like liquid rubber, makes it waterproof already on the base.
Make several layers and the cement not too thik. At the end paint it with epoxy resin,
in this you can ad some colour as well, and sprinkel the wet epoxy with sand, stones or what
will serve you. I hope you find epoxy, do not use polyester it could poisoning your animals.
I had a rocky pool almos 6 months outdoor and it still was smelling strong.
Hope it will help a little
Geetings
Rene