[hoppycalif]

Just to be safe, you should also have a small silicon carbide sharpening stone available. Some tanks are made with glass that has not had the sharp corners on the top edge rounded off. If you find that to be the case, the stone will easily get rid of that sharp edge. When you get through you won't have an ADA quality tank, but I have seen tanks done this way that look very good.

 

[hoppycalif]

I'm far from an expert on this, but my understanding is that the silicon that provides the strength in a joint is only that which is in the thin layer between the two pieces of glass. At most the fillet of silicon in the corners helps prevent leakage. Silicone sealant is very flexible, so a thick gob will easily deflect under stress, but a thin layer just barely deflects under stress.