<a href=showthread.php?s=&postid=15580450#post15580450 target=_blank>Originally posted</a> by der_wille_zur_macht
Just to be clear, if someone was building a sump totally out of acrylic, then the ONLY acceptable method is to use acrylic solvents to bond the parts together. If someone were using acrylic to make baffles in a glass tank to build a sump, then using silicone is OK. Cut the baffles so they fit loose (acrylic isn't very stable and can expand enough to crack a glass tank), and rough the edges up with coarse sandpaper, then use plenty of silicone - it doesn't stick to the plastic well.