I work at a board game cafe, and we have just about every one of the Lego board games in our collection. However they're basically never playable, as kids will open several of them and sack them for parts to build insane rainbow warrior creations (an instinct I admire, but it doesn't help the next folks who want to play the game). So I'm looking at gluing them together (except, of course, where required by gameplay). But what glue is best for a truly permanent bond between bricks?