Have you seem Khaosinc's thread on RC?(if you havnt I highly recommend reading it...by far one of the most entertaining threads Ive ever read)
http://www.reefcentral.com/forums/sh...readid=1650383 He used spray foam to bond his structures together....I never really looked into it, as far as how many others have used it, is it reef safe etc...might be worth checking out.
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260g mixed reef, 105g sump, water blaster 7000 return, Bubble King SM 300 skimmer, Aqua Controller Jr, 4 radions, 3 Tunze 6055s,1 tunze 6065, 2 Vortech MP40s, Vortech MP20, Tunze ATO, GHL SA2 doser, 2 TLF reactors (1 carbon, 1 rowa).
http://www.canreef.com/vbulletin/showthread.php?t=50034 . Tank Video here
http://www.vimeo.com/2304609 and here
http://www.vimeo.com/16591694