Aquarium repair

On Friday, 1 September 1995, David Webb wrote:
On Friday, 1 September 1995, David Webb wrote:

> I have a 50 gallon short with a broken bottom.  The glass in the
> bottom is 1/2" thick and is prohibitively expensive to replace.
> I'm planning on setting this tank up as a paladarium (3" substrate,
> 3" water).
He goes on to ask if sheets of thinner glass can be laminated together to
make a new bottom.

I have a fair amount of experience laminating wood, and have learned that the
strength of any lamination that will be subjected to long-term loads is
determined by the ability of the adhesive used to resist a phenomenon called

Two sheets of glass glued together will be only slightly stronger than a
single sheet unless they are *rigidly* bonded together. I know almost nothing
about bonding glass, but I am relatively certain that silicone will not do
the job. 

My seat of the pants judgement is that the 1/4" glass will be sufficient for
use of the tank as a paladarium. For peace of mind,one could glue a small
block of wood or plastic of appropriate thickness to the underside center of
the bottom to serve as a support.