experienced with 3D puzzles?

[Luv2Roam]

I have one of Cindy's Castle coming.
I have never assembled a 3D puzzle, but sounds like fun.
Now the question -- I would like to leave it assembled. Are the 3D puzzles stable once together, or are they fragile?
Can that puzzle goop be used to hold it together? Anyone here use that or something similar?

 

[tigger2esq]

I got the Cindy's castle 3D one off of Ebay a few years ago. DH and I spent aout 3 days trying to put it together (the directions were just pictures--nothing written) we DID eventually get it done and it looked cool. it is pretty stable--the pieces were backed with a foam board type to make them thicker and sturdier than regualr puzzle pieces. I imagine the puzzle goop stuff would work but it would be hard to get it on the inside portion since completed! We left ours up for about a week on the dininr room table and then took it apart and I havent seen it since... hmmmmm.