I used to work as an application engineer in the window business and we tested many kinds of sealant and elastomeric seals under accelerated aging conditions.
Silicone is some really awesome stuff and General Electric actually issued a guarantee that it would last for 100 years without the windows popping out from seal failure.
I have heard more than once that a tank stored Outdoors over the winter leaked when it was refilled, even though the tank appeared fine and was only a couple years old.
This issue was brought up by
Jexnell
in another thread.
Slicone does not get brittle. It was invented to withstand the scorching heat of the sun and the freezing cold of outer space.
This is exactly what astronauts report when they walk in space: that one side of their suit is burning hot and the other side of their suit is freezing cold. All the rubber joints are made of silicone rubber. It is some of the toughest stuff ever invented but it must be applied in the correct manner to work.
The reason storing an aquarium in the cold is bad is that the silicone joints are not designed for excess thermal movement. They're designed for maximum strength without perceptible stretching.
In fact, it is very bad to let one get too cold or too hot too fast. There's not a sufficient volume of silicone in the corner joints to absorb much thermal movement without internal cohesive failure of the silicone.
But you're supposed to get an aquarium to temp and leave it there forever . . . that's the goal.
Because of that you don't have real thermal stresses on the aquarium.
The important stresses are all due to water pressure.
Many buildings have the glass glued onto the outside with silicone just like an aquarium, and these buildings survive in the Frozen North West and the Rocky Mountains.
But those joints do not have to withstand the pressures of a fish tank and only air pressure. They are very fat joints and they allow the Windows to expand and contract and the building to sway, without the windows popping out.
If the silicone in your aquarium stretched that much you would get scared looking at the bulging corners.
Silicone is some really awesome stuff and General Electric actually issued a guarantee that it would last for 100 years without the windows popping out from seal failure.
I have heard more than once that a tank stored Outdoors over the winter leaked when it was refilled, even though the tank appeared fine and was only a couple years old.
This issue was brought up by
Jexnell
in another thread.Forgive me Jexnell, but this is only semi true. The Silicone will fail but that is not why.
Slicone does not get brittle. It was invented to withstand the scorching heat of the sun and the freezing cold of outer space.
This is exactly what astronauts report when they walk in space: that one side of their suit is burning hot and the other side of their suit is freezing cold. All the rubber joints are made of silicone rubber. It is some of the toughest stuff ever invented but it must be applied in the correct manner to work.
The reason storing an aquarium in the cold is bad is that the silicone joints are not designed for excess thermal movement. They're designed for maximum strength without perceptible stretching.
In fact, it is very bad to let one get too cold or too hot too fast. There's not a sufficient volume of silicone in the corner joints to absorb much thermal movement without internal cohesive failure of the silicone.
But you're supposed to get an aquarium to temp and leave it there forever . . . that's the goal.
Because of that you don't have real thermal stresses on the aquarium.
The important stresses are all due to water pressure.
Many buildings have the glass glued onto the outside with silicone just like an aquarium, and these buildings survive in the Frozen North West and the Rocky Mountains.
But those joints do not have to withstand the pressures of a fish tank and only air pressure. They are very fat joints and they allow the Windows to expand and contract and the building to sway, without the windows popping out.
If the silicone in your aquarium stretched that much you would get scared looking at the bulging corners.
