? on tank building

[GeeTee]

I was just wondering whether when building your own tank do you glue to the top of the base, or the side of the base.

I built my first tank and glued to the top,but since building it noticed a lot in the shops were glued to the sides.

My tank dimensions are 80x40x40(at the time I had no idea about standard tank sizes)and haven't had any leaks so it probably does matter but I would be interested in your reasons or preference on which way to go.

This is my tank

This is a more recent pic.The fish have changed a bit since this was taken.

[Robert Smith]

I built my own tank (from zero knowldge) and siliconed the walls on top of the base. My logic was that it takes more force to shear (sidways) than to stretch (outwards).

I don't like those black strips cheap tanks have down their edges, so mine is just silicone. But I got a bit nervous about the weight of water and lack of my experience, so I put metal corner reinforcing on the outside of the bottom corners to strengthen agains 'creep' over time. My tank is free-standing, so there is no base to provide resistance against creep.

It may be easier to rest the glass walls on the worktop, but I thought that if you did it that way you'll glue the base to the workbench! I put all 4 walls in place with a matchstick under/between at each end as a spacer and used masking tape to hold the walls in place. I then just siliconed into the space (slowly and with excess squeezed towards the inside of the tank to ensure no air bubbles in the silicone). Once it was dry I removed the match sticks and then siliconed those spaces. The excess on the inside was cut away with a razor blade.

[alanmin4304]

In my observation and experience most tanks are built with the sides and ends sitting on the base. The main reason is that the glass does not have to be cut as accurately. With larger tanks I usually glue the front and back to the edge of the base and the ends sitting on top, the theory being that the bond has less strength in shear. I also scratch the face edges to be glued with sand paper to give a better bond but only on very large tanks. E.g. I made a tank once out of three doors in toughened glass from a commercial building and built it that way but also added 50mm straps to increase the bond area.

[Cyberfin]

I've had success placing the sides on top of the base with the two ends placed inside the front and back pane. I also clean the surface to be siliconed with acetone or methylated spirits on a paper towel. 24hrs after assembling (some wait 48hrs) I filled it up and let it sit for another 24hrs, periodically checking for leaks - Its a good idea to do this outside. I made a 2000x100x70cm tank this way. When I returned from a weekend away I was greeted by my fish flapping in 5mm of water; the bottom cracked, the seals held.