Question regarding epoxy

[tazdevil]

Ok, this may be a dumb question, but, I am building a sump out of a 20 gallon Long for my 75. I am wondering if standard aquarium epoxy will hold glass and acrylic together.

 

[reefland]

Nope, it's not a glue and its not even sticky (except to your fingers).

 

[dsb1829]

I am gonna have to dissagree here. It will hold the dividers in place if used correctly. Richard is correct in stating the nature of the 2-part epoxy. However it does bond well to most surfaces. If you used it to construct a channel and then slide the acrylic dividers into the channel it would work fine. Best if done while the tank is dry.

However it would work far better to have a local glass shop cut a few peices of glass to fit the sump as dividers and then silicone these in place. Silicone adheres to glass far better than anything does to acrylic. About the only thing acrylic bonds to is other cyanoacrylates like polycarbonate, lexan, and acrylic.

 

[reefland]

I would think the differences in water pressure on each side of the baffle would be more than enough to break the weak bond epoxy would have to glass and acrylic.

As you said silicone would be better and yet siliconed baffles often fail from the pressure difference. I don't see how something with a weaker bond could hold.

 

[tazdevil]

Update: It held just fine, was able to lift the tank with it (used the ge aquarium silicone epoxy) bonded one side, cured for 24 hours, bonded opposite side, cured for 48 hours, filled with water. The water is about equal height on both sides, creating an almost equal pressure on both sides. When filling, however, only filled the one side (pre-skimmer) as a test, and no bowing was appreciable. This is a small sump (20gallon long).

 

[reefland]

When doing a water change would one side get lower than the other?

I'm thinking the epoxy is porus. It gets colonized and boring organism will find it sooner or later. Be interesting to see how it holds up.