Dart Den

I recently built my first background and am having a problem with my Great Stuff. I used the red-can kind and for some reason about a week after I built it it is showing signs of receding from around my drift wood. What could be the cause of this ? Has anyone had this problem ? Am I using the right kind of Great Stuff ? I siliconed the back of the tank before I used it and then let it harden over night (both the silicone and the great stuff).

Its not uncommon for greatstuff to shrink a bit for the first few weeks.

When I work on a cage, I usually let it sit for at least a week and watch for shrinkage before I cover with silicone.

Frank

Thank you much for the insight. Am I using the right kind of Great Stuff ?

Yep, the "Red Can" works well, but the black can will expand more,but is a little harder to work with in my opinion, but is great for filling big holes.