How old is too old?

[Longimanus]

I have an opportunity to buy a 55 gallon tank, and I found out it is made by O'Dell, who I don't think even exists anymore, and is 16-18 years old.

Is this too old? I would re-seal it of course, but would the whole thing need to be taken apart and put back together? Or would your standard re-silicone be sufficient? Would any of you buy a tank this old? Does the glass become brittle or anything after so long?

 

[chefjamesscott]

i have some tanks 25+ no probs

 

[12 Volt Man]

I had tanks going 19 years straight when I sold them, never been resealed.
but never drained down and emptied either. held water straight for 19 years..

I would reseal and you are good to go for another 20 years before another reseal..

at that point your tank will be 40 years old.

then it might be time to buy a new one

 

[Longimanus]

Thanks guys, that is reasuring.

 

[Toby_H]

1) No glass does not degrade... It only scratches, so if the glass isn't scratched up more than you consider acceptible it (the glass) is as good as new...

2) If the tank holds water, there is no reason to reseal it. Many tanks have held water well beyond 16~18 years this one has.

3) Silicone does not adhere to cured silicone very well. Because of this fact resealing a tank consists of taking the whole thing apart and rebuilding it. Simply overlaying the old silicone with new may slow down a leak (if one exists) but in a rather short time it will reappear (again, if it existed).

4) My sister is currently using a 40 high (30" x 12" @ 25" tall) that I got when I was about 10 years old (24 years ago). This tank has never been resealed and spent about 10 years in storage. Also, my father bought a few tanks when he first got home from Viet Nam (1969) and he turned them over to me as a kid and I had them in use until the early 90s. To my knowledge they were sold at a garage sale and didn't leak (never resealed).

 

[mushroomsoup]

actually glass in the form you see it is considered a liquid. Although it takes many years, at some point in the life time of the glass the top will become thinner due to gravity.

 

[Neophyte]

actually glass in the form you see it is considered a liquid. Although it takes many years, at some point in the life time of the glass the top will become thinner due to gravity.

Seconded but only really old tanks.

The term is an amorphous solid, it takes quite some time before you have to worry about it though and the glass would be visually distorted. For an example look at a house with 60+ year old windows and you will see how the glass has become irregular, thicker at the bottom and thinner at the top of the pane.

 

[velanarris]

FYI: machined and tempered glasses (any fishtank made within the past 20 years) are not amorphous solids. They do not deform or distort over time.

Contrary to popular belief most glass does not distort over even hundreds of years. If you remember the field trip to the old homes from the 1700's the glass in those windows was manufactured unevenly and did not thin out due to time.

 

[Neophyte]

FYI: machined and tempered glasses (any fishtank made within the past 20 years) are not amorphous solids. They do not deform or distort over time.

My 5th grade science teacher said so, so it has to be true!

 

[Toby_H]

actually glass in the form you see it is considered a liquid. Although it takes many years, at some point in the life time of the glass the top will become thinner due to gravity.

Although this is true (to a degree) it is not really a relevant point in this topic...

For an example look at a house with 60+ year old windows and you will see how the glass has become irregular, thicker at the bottom and thinner at the top of the pane.

Since the pressure on the glass is much greater at the bottom than at the top... the glass being thicker at the bottom and thinner at the top does not really work against you until the difference is exceptional... and we have examples of glass being hundreds of years old and the difference not yet being exceptional (think stained glass in very old churches)...

The glass changing thickness can effect the seals... but as sited above by myself as well as others, there have been examples of tanks being in use for over 20 years and this not having any effect... Also the probability of resealing has already been considered from the first post.