My great stuff did some weird stuff.

[hyla23]

I was in the process of making a 10 gallon tank and I stood it up vertically and went and siliconed egg crate on the back wall to make ledges then I sprayed great stuff all over it to make the background and I let the tank sit for 2 days to totally dry in my reptile room and the great stuff shrunk and pulled all the siliconed egg crate off the glass and eventually it popped off the wall. I am thinking about siliconing the background back on and just fill around it with great stuff but I have made many tanks like this and the great stuff has never done this. Does anybody know why or how I can prevent this from happening? Also where can I get some plastic hinges and U channels for my front glass door I'm building?

[NathalieB]

spraying your windows with a little bit of water before you apply the GS will make it stick better to your background.

[rjmarchisi]

If you also sprayed on the greatstuff too thick, this will also cause the "expanding" foam to contract a bit after curing. If you work up thinner layers there will be alot less of the contraction.