INFO on old 135 gallon tank with no center brace.

bozatron

Gambusia
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Apr 12, 2012
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Dubai
Just a thought but if the tank has held water since 1987 then I dont think the bowing is a problem. It must have bowed all its life, glass doesn't "get soft" with age, so dont worry and get her wet.
 

Drstrangelove

Potamotrygon
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Oct 21, 2012
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Can anyone let me know if its normal for an old 1987 1/2" glass tank with no center brace to bow about a 1/4"? the tank is 72"x 18"x 23" in good condition it hold water fine but im just curious about the bow. I hear mix comment like, older tanks with no center brace bow and then hear they aren't suppose too. anyone own one or know about them let know. thanks. By the way this tank never had a center brace.:help2:
I'm not sure I understand how 1/2" glass can bow 1/4".

1) the glass is thicker than it needs to be for that tank.
2) glass isn't really supposed to be able to bow that much (like acrylic, steel or wood.)
3) bowing 50% of the thickness of the glass is comparable to a 'safety factor' of 1.0, or no safety factor.

My guess is the glass is thinner (about 8mm) and that the 'bow' is significantly less. If glass for that tank were 1/2" wide (12.7mm), it should have a deflection of less than 1/10th of a mm (1/254th of an inch), and would certainly not need a brace.
 

cichlidzoid

Jack Dempsey
MFK Member
Dec 13, 2012
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NJ
hey duanes thank for your info, but your tank bow? I also posted a pic of the glass
 

doomiedee

Fire Eel
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Nov 13, 2011
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I have an old 75 that i found in the garbage it has 3/8" glass and no center brace and it doesn't bow period. You could always silicone glass braces on the inside top and bottom to help from bowing


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doomiedee

Fire Eel
MFK Member
Nov 13, 2011
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Waterbury
I'm not sure I understand how 1/2" glass can bow 1/4".

1) the glass is thicker than it needs to be for that tank.
2) glass isn't really supposed to be able to bow that much (like acrylic, steel or wood.)
3) bowing 50% of the thickness of the glass is comparable to a 'safety factor' of 1.0, or no safety factor.

My guess is the glass is thinner (about 8mm) and that the 'bow' is significantly less. If glass for that tank were 1/2" wide (12.7mm), it should have a deflection of less than 1/10th of a mm (1/254th of an inch), and would certainly not need a brace.
+1 1/2" glass bowing a 1/4" will definitely be at its breaking point. I don't get how this tank hasn't busted yet. I made a divider for my 15 that stretched the glass barely an 1/8" and that started leaking in an within the hour.


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DIDYSIS

Mantilla Stingray
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Feb 9, 2012
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West Jordan Utah
So did you actually fill the tank and see that it bows?? If you want to add a peice of glass in the middle top for a little extra support go for it, if you want to run as is you can as well, just like today they make tanks with no frames bit they are thicker glass to make up for not having center braces and frames.

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Drstrangelove

Potamotrygon
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Oct 21, 2012
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thanks for the feed back. but here is a pic of the glass View attachment 919947 its half inch.
Good pic. Looks like 12mm-1/2". That is a good thickness, but 1/4" bowing is not a good thing. Bracing it so it does not bow would be a better long term solution unless you plan to replace the tank. Unless the glass was made with the curvature (which presumably it wasn't), then it's stressed. It might handle that stress for a long time or not.
 

badassissimo

Candiru
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Mar 26, 2008
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I'm hoping to learn something here. I have a 125 with a brace and the brace is so gunked up, light doesn't hardly penetrate. I hate that and don't know what to try except taking it off and replacing it. I would love to buy another tank and buff this one top to bottom since there are scratches but I don't have that kind of budget. If there is a hard work solution, I'm down. Else, could I just cut the silicone on it and take the centerbrace out? Maybe that would be bad since it was built like that? Maybe it's not a problem since this thread is about a 135 with no brace that has the same thickness glass? I have heard that some glass is produced to a certain caliber and can only withstand so much pressure and higher caliber glass would withstand more pressure. Not much more, but a little more. I'd like to find out for sure so I can get light to the middle of my tank. It's been a great hiding spot for as long as I can remember. I bought this tank used and leaking once upon a time and assumed I could take whatever discoloration off with typical scrubbing. Mistakes were made. Subscribed.
 
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