"Richard Sexton" wrote in message
...
In article ,
Angrie.Woman wrote:
My 29 gallon is probably 20 years old. Today, I was scraping a little
algae
off with a magnet, and I saw a small flap of loose silicone. So, what is
the lifespan of a siliconed tank - anybody know?

Ocasionally - very very occasionally one, fails. I've heard of exactly one
letting go and it wasn't old. They just don't seem to fail. My newest tank
is 25 years old the oldest probably 10 yrs older than that. Use of
silicone
as a glass glue was first published as far as I can see, in Robert P.L.
Straugns book _The Salt Water Aquarium In The Home_. Metal was a great
concern and problem and he tried fooling around with a bunch of different
things including epoxy to make an "all glass aquarium". Such things
were unheard of. None worked. Then he tried the "new silicone
bathtub sealant". It worked and the rest is history. This was in the
early to mid 1960s and dollars to donuts that tank is still working
just fine today. IMO the first "all glass" (back then it was a
type of tank, not a brand) ought to be in some sort of museum.

I got into fish in the early 70s as a kid and at tht time half the
tanks in the store were metal framed and half were all-glass.

The warrenty on silicone is 30 years. They keep bumping it up
as the stuff just seems to last forever.

Don't worry about a dangling bit of silicone, I routinely
cut all mine away anyway so the only stuff that's left is
that which bonds the actual glass. There's no reason for any
excess to be there, it's just more convenient for the manufacturor
to smooth the wet silicone down than to remove it.
--
I have had one fail on me, the tank was about 10 years old. the whole seem
along the bottom front opened up and drained half the tank.
The main reason the tank failed was because the base board the tank sat on
had become wet ( I had a Hoplo catfish that used to spit water over the side
of the tank) and started to bow and no longer gave proper support to the
tank or the polystyrene it was resting on.

Tony