Silicone rock wall

[Miller Aquatic]

I am looking to create a side rock wall and was wondering if I could put a big glob of silicone and push the dry rock pieces in. I’m thinking a whole sheet of silicone, push the rock in and while still (wet) sprinkle sand over. It wouldn’t be fighting gravity while drying because I’ll have it on its side. This is an empty 135g btw. I was wondering if it would work or not because of the pourus rocks. The rocks aren’t very heavy. I was thinking like the egg crate foam wall builds but I already have aquarium silicone.

 

[twentyleagues]

I’ve heard good things about jb water weld would you think that would be strong enough?

I dont know for sure as I have not used it to adhere something to glass. My thought on it would be it will fail eventually but not sure. I have created many backgrounds over the years. Longest running one is the one in my 75g I used spray foam cut pieces of foam to make tree/root structures then painted them with a thin layer of cement then painted with drylock tinted with cement coloring then coated in a thin layer of pond shield. It has been in the tank for over 10 years I use silicon to stick it to the glass and it has held.

I used pond foam to attach the black lava rocks in my tanganyika tank. I find pieces of black pond foam floating around every week this has been continual since I put it together 5 years ago. I dont know if its the fish or natural decomposition.

Silicone works best on two flat nonporous surfaces. Most of the backgrounds I have made get a coat or two of the clear pond shield on all the surfaces and that is then attached to the glass using silcone. Those have never failed and I have taken a couple off and its not easy.

I have made backgrounds for a lot of tanks. Most of them are carved insulating foam coated in drylock tinted to achieve the colors of natural stone or wood typically I used egg crate as the back and spray foam to hold the carved foam to it. The back is typically coated in the clear or black pond shield and siliconed into place. I have made pieces for locals that have been in tanks for years. My agracrete structures are also siliconed in place I dont coat them but the back is typically smooth at least one is still in use in a 120g reef that has been running since 2008.
What I have found out is silicone glass to rock the silicone bearing the weight will eventually fail. Black pond foam works well and will adhere to rock and glass may eventually fail, definitely will flake off from time to time. Silicone to smooth will last. Silicone used to hold a large structure where weight is resting on the bottom of tank seems to last pretty well.

 

[vlangel]

Check out @Chasmodes Potomac River biotope tank. He made an amazing wall that looks like river rock. That build might be at the beginning of his Chesapeake Oyster biotope build. Anyway his tanks are a work of art! Maybe he will jump in and share where you can find how he made the wall.

 

[Miller Aquatic]

Ok so I have the same idea but with jb epoxy and e Marco 400 should I use both or which one should I use? Will this cement be a good bond with rock to glass?

 

[rsp919]

I did something similar. I bought 2 pieces of blue acrylic. Then I laid out the rocks where I wanted them and scuffed the acrylic with an angle grinder so the silicone would have a rough surface to hold on to. Been up and running about a year now and still very strong. I tried pulling a piece the other day and no dice.

 

[Holgersson]

I did something similar. I bought 2 pieces of blue acrylic. Then I laid out the rocks where I wanted them and scuffed the acrylic with an angle grinder so the silicone would have a rough surface to hold on to. Been up and running about a year now and still very strong. I tried pulling a piece the other day and no dice.

Did you just put them in the tank, or are they sealed with silicone to keep dirt and things from getting in between the acrylic and the glass?