Glass Overlap on Plywood

[gavbuk]

Hi All

Currently in the planning stages of a large'ish plywood tank to build a reef in. I've read a number of threads here regarding plywood builds and everyone seems to have a different overlap between the glass and plywood.

The glass in the tank is planned to be 72" x 30". I'd prefer this viewable as much as possible but dont want to rish the pressure against the glass breaking the surrounding plywood as the overlap is too small. Depending on the required overlap, I imagine the maximum the tank will be is 40" deep. Maximum width would be 80" and the front to back dimension is planned to be around 48" but that includes a 6" section at the rear to accomodate a weir to feed in to a sump.

So...any ideas how I calculate require overlap needed?

Thanks in advance

 

[kallmond]

I think the reason every build is different is because there is no real standard or calculator. Every builder goes with their gut.

 

[Pharaoh]

I'm not 100% on this, but A good rule of thumb would be 2 times the thickness of the glass as a minimum.

 

[Muni]

I'm not 100% on this, but A good rule of thumb would be 2 times the thickness of the glass as a minimum.

Sounds reasonable.

I'm using about 1 1/2-2 inches of overlap for my 72 x 30 piece of glass. 1/2" thickness.