Does two-part resin (for DIY rock wall) need to cure?

[squatchaquarist]

I'd like to make a 3D background for a 125g. I'm thinking to go the egg crate, pond foam, and crushed coral/sand route with pieces of rock. I've read about using a two-part resin over everything -- does this need cure time like cement? Or will it be safe for use as soon as it dries?

Could I use pond foam with sand pressed into it without a resin covering? I have some two-part on hand, but not sure if it is enough for a large-fish surface area (and it is rather expensive).

 

[sp1187]

first option
I used the first to make my aquascape.

second option

 

[squatchaquarist]

first option
I used the first to make my aquascape.

second option

Wow, I love the first one. So after 16 hours it is completely safe for critters?

 

[sp1187]

Wow, I love the first one. So after 16 hours it is completely safe for critters?

yep.
skip the paint. coraline grows on it.
corals attach/encrust on it.