I find it interesting that some are having such poor luck with PC and others have 500G tanks that are perfect. I am starting to lean towards either tecnique or process. as has been said Acetone DOES Leave a residue behind. when I spoke witht the guys at Liquid Rubber in Calgary they suggested using Butyl Rubber to seal the glass as it doesn't effect the PC. I haven't looked into it yet as to weather it is fish safe but if the glass is sealed in before the PC is applied then the PC will be over the Butyl Rubber therefore eliminating the need for it to be fish safe it would be like a added seal with a barrier between. Pete what you said about it bonding well where its thicker I find interesting. I am hoping to get ahold of the guys tomorrow and ask a few questions. maybe they can clue us into the answers