Re- Siliconing questions

[crossleymarko]

The clear silicone will still be visible from the outside of the tank and the black will not last to long.

this is true... the strength comes from the glass being bonded to gether and the excess silicone that ooses out being smeared.. also silicone doesnt bond to cured silicone as someone has also mentioned.. maybe painting it with a quality pond resin.. i would do a bench test though on some cured silicone first... just a thought..