What is the official word on adhering acrylic to glass w/ silicone?

[LiquidLunch]

I've STFA's and found many contradictions. The more I search, the more I just want to piss away $200-$300 on a custom acrylic sump. Ideally, I would like to buy a 30gal glass tank and silicone in (4) acrylic baffles. I have heard that the silicone will work, but won't hold under pressure. I want to do it right the first time and not have to worry about something breaking loose when I'm on vacation.

[chlskt]

Not sure on an official word, but for sealing acrylic to glass, your best bet would be to use "Weld-on". I found it at a Plastics store. Home Depot and Lowe's looked at me like I was a girl and had no clue what I was talking about. If you go to www.Melevsreef.com he explains in the, tools needed for a sump, that the Weld-on actually somewhat melts the acrylic to the glass to get a good seal on it. Hope that helps.


Jeni

[the_colonel]

I have three acrylic baffles in my glass sump, and used regular silicone. You just need to use alot. Keep in mind there should not be much pressure on the baffels since you have water on both sides of the baffles. When I took out my old baffels (also acrylic siliconed to glass) I could not break them loose, had to use a razor blade to cut away the silicone first.

Just my $0.02

[yardboy]

Yep, one of my first sump designs I had an acrylic box in one corner and when I realized it wouldn't work well, I had a heck of a time removing it from the grip of silicone. My present tank's acrylic overflows are all put on with silicone, as are 100% of the one's I've seen at lfs's.

[Whale4]

I just made my sump this week and used silicone. like somebody said before there should be no pressure building on the plexiglass. I have a couple freinds who have had their tanks up now for about 2 years and i copied their set up. if done right i wouldnt worry

[jbplay]

I built my sump from a 29g AGA and put in 4 acrylic baffles using DAP Aquarium silicone from Home Depot. It's been working great since I put it in about six weeks ago.

[wharyat]

For short term, 3-5 years it's great.

[craigGP]

the right version of weld-on would be ideal. silicone is commonly used so it must work. two issues to think about: 1. make sure to use thick enough acrylic that it won't bow from the pressure and pull out of the silicone, and 2. remember that acrylic slightly expands when it absorbs water. too tight of a fit and you could shatter the glass tank.

hope that helps

craig

[RWD]

Check out this thread:
http://www.thereeftank.com/forums/sh...highlight=sump