help please with glass thickness for viewing window held in frame

[adhdan]

will 15mm lowiron annealed glass be ok for a window in a plywood aquarium that is 1800lx700wx800h and the front viewing window is 1660x660, the glass panel is 1740x740 allowing for a 40mm overlap on all 4 sides
The online calculator says i should use thicker glass (18mm) but with it being fully supported @ the top & being smaller then the external size of the tank it will increase safety factor and allow for thinner glass?
thanks
Dan

 

[eatyourpeas]

The numbers I come up for your tank dimensions (using external values) are 16mm with SF 2.24 and 20mm SF 3.5

I think since you are using glass, your horizontal dimension is the one to watch out for when it comes to the pressure exerted by the water volume. I would think 15mm may work with careful bracing front to back on both top and bottom (min. 2braces?). Also, this piece of glass is going to make it front heavy, so balancing the overall support is something important to consider.

 

[Colin_T]

I'm assuming you have some support members across the top of the tank from front to back?

In Australia we have tanks that are 6 foot long x 2 ft wide x 2 ft high and they are made from 10mm thick glass.

Tanks that are 6ft long x 24inches wide x 30 inches high are usually 12mm thick glass.

Tanks that are 6ft long x 30 inches wide x 30 inches high are normally 15mm thick glass. Our tanks have cross members across the top to stop the sides bulging outwards.

15mm thick glass should be sufficient for the front panel. However, your tank is 80cm (32inches) high and that will put a bit more pressure on the glass.

Why are you making the tank so high?
It's going to be awful to try and decorate, clean or get dead fish out of.