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Broken Tank Support

16K views 57 replies 8 participants last post by  Tazman 
#1 ·
My cat went after a fly, like usual, except he knocked a picture off the wall and broke the middle support of my gallon tank. :cry: I managed to pull the broken pieces out before to much damage was done. I did take it down below half mark on the tank. I only have a few guppies left after the accident and the lower water doesn't seem to be messing with them. All my plants besides the Anubias and my floating hornwart have been moved to my other betta tanks till I can get it fixed. Do you guys have any suggestions on what I could do with it for now since I have to get to a glass shop to have a new piece cut? What would you all do about it?

PS: sorry if this is in the wrong forum.
 
#3 ·
The tank is an all glass 55 gallon aquarium. The support across the top is glass, 1/4th inch thick. My cat broke it by knocking the picture off the wall above the tank and it had hit the middle support in such a way as to break the glass. I will post a pic as soon as I get my camera working.
 
#5 · (Edited)
This is the first time I seen something like that. The glass appears to have been put there to support something laying on top of it. Every tank that I have seen over many years had one piece plastic framing all around the tank including a center support that is also molded into the framing.
How old is this tank? If it was purchased used, I suspect a former owner cut out the center support. This places a lot of pressure on the front and rear glass. I don't see how a piece of glass can support the front and rear glass. Unless this tank was designed for reptiles. These tanks do not reqiuire a center brace. Then if thats the case, I would not use it for a fish tank. its an accident waiting to happen.
 
#7 ·
This is how the tank was purchased new about 12 years ago as a fish aquarium. The top support was used to keep the front and back glass from bowing out due to the water pressure. It is still all original sealant, frame, and glass. The dimensions are 48" long X 12" wide X 20" deep.
 
#8 ·
After reading your post again, I was thinking that I might just make this tank into a Bombina Orientalis (Fire-Bellied Toad) Vivarium. They don't require much water in thier enclosure so should not stress the glass very much. I can also keep what is left of my guppy fish in the water section.
 
#10 ·
rjordan390's advice is totally wrong so far. That middle brace is indeed critical for the structure of the tank, and is a common construction seen on many aquariums. You can verify how crucial it was by taking a tape measure when the tank is filled up, and you can check how much the middle is bowing out now. I know from experience because I've recently had bracing issues of my own. Silicone sealant is nearly always used to fix the brace in place because of its surprising strength and flexibility. If you you do some research on DIY aquarium building, you'll see that it's standard practice.

For now, lower the water level to a point where the bowing isn't too extreme (for a tank your size, I'd say like 2-3 mm altogether combining both sides) and get a new piece of glass cut asap. You can easily fix it in again with silicone sealant - but remember that you will have to lower the water level to a point where the bowing is hardly occuring before you slilicone the brace back into place. Good luck!
 
#13 ·
<You can easily fix it in again with silicone sealant - but remember that you will have to lower the water level to a point where the bowing is hardly occuring before you slilicone the brace back into place.>

I beg to differ.
The poster is not an aquarium builder. If DIY are getting away using sealant to hold a brace then they are pushing their luck. You might want to ask the manufacturers why they have a center brace as an integral part of their large aquariums. its true that the sealant has good holding power but because its more flexable, manufacturers feel its safer to have proper bracing and not depend on sealant to do more then its intended purpose.
 
#16 ·
As far as I know, manufacturers build (or commonly used to build, as Varkolak says in the post above me) tanks in this way attaching glass center braces to the inside of the front and back panes using silicone. You are arguing that the glass brace was put in by another owner, but the poster hasn't indicated that there's any traces of another type of brace being broken/replaced, so I think it's more likely that seeing that it's an older tank, the glass brace is factory-original and if the original poster can recreate this glass brace, things should be OK. I would be veer on the side of paranoia though, and over-build the brace slightly - use thicker glass. It's important to use glass and not plexiglass, because silicone bonds permanently to glass but not to plexiglass, along with several other types of plastic. Actually ideally the brace would be put directly on the aquarium glass theoretically for this reason, but if the manufacturer chose to attach it to the plastic frame, there must be a good reason for it (obviously that particular plastic has no problem bonding to silicone) and simply re-creating the original is probably simplest and safest.

Rjordan, look up Euro-bracing for a type of tank that is very common these days, especially with tanks without a cover. Up to a certain size of tank, Euro-bracing without cross braces is another option, and those are built with pure glass longitudinal braces attached to all four sides of the aquarium using silicone. Silicone also has the advantage in being so flexible that it evens out any unevenness in the joints, which otherwise might lead to certain points of the glass receiving concentrated amounts of strain resulting in leaks/cracks/tank explosions. The way I understand it, the combination of its bonding strength and its flexibility is what makes it a good adhesive for aquarium building.
 
#14 ·
<Sorry Rjordan, but what do you think the aquarium sealant is doing at the seams of the aquarium? Do you realize how much hydrostatic pressure the seams have to be able to support?>

The seams at the corners are the strongest part of the aquarium because of the one piece contruction of the top and bottom with a center brace on each. Most of the pressure will be on the front and rear glass. Take away the center brace and you compromise safety.
 
#15 ·
I've looked into building aquariums and have talked to several who have built many, most of the time the only thing holding aquariums together is the silicon - the top and bottom trim is just that, a trim for looks. I will agree that a center brace is important for tall aquariums but saying that because its made of glass its not strong enough shows a lack of knowledge. Glass braces were the standard for several companies at one point and many only went to plastic because its cheaper material. I myself have a 50-60gallon with a 3/8in glass panel in the center as the support brace and I would guarantee it to be stronger then the flimsy pieces of plastic my 150 gallon has as braces. You can easily repair your tanks glass support by lowering the water level down enough that the measurements on the ends of the tank are within 2-3mm of the measurement of the center where the brace was. Then use a razor blade to remove the old silicon, use alcohol to clean the area, then put an even bead of silicon on the rim of the glass under the lip formed by the trim. Then gently press the new panel of glass into place and hold it in place for 5-10minutes; If it is a tight fit you may not need to hold it very long. Once its secure but before the silicon finishes curing add a thin layer to seal the corners on the inside for a smooth seam. Wait at least 24hrs before returning the water level to its norm to allow the silicon to completely cure.

If you want added strength and don't trust yourself then you can add a 1/2 to 1 inch by 1/4 by the width of the panel piece of scrap glass under your brace by adding silicon to one side and gently pressing them into place snug underneath but thats really unnecessary for a tank your size unless you plan on putting a lot of weight on it (I only added braces on a shelf that holds 15-20lbs of sand in a tank).

Hope this helps you if you aren't set on making it into a frog habitat :lol:
Oh and be carefully breaking the rest of that glass brace off, it wont be easy to remove so use heavy gloves and work at it with a razor blade
 
#17 ·
I would highly recommend avoid using alcohol as a cleaner with a tank with fish in. If any is spilled in the tank by accident it can be deadly to fish.

Can the Original Poster post a picture of the tank to get an idea of what we are dealing with before we offer suggestions for fixes?

Depending on the thickness of glass used in the manufacture of the tank, not all tanks require bracing. my 75g tank has no bracing on it and none is required as it is made from thicker glass. The deflection when fully filled is about 1mm or less.
 
#18 · (Edited)
Hmm. I think if the tank was safe without the brace, the manufacturer would not bother spending money putting one in. ;) To save on costs, tanks can be built with thinner glass PROVIDED proper bracing is put in. You can only really have it one way or another, and as I said, it doesn't make much sense that a mass-manufacturer would put in a hefty piece of glass there "just for the heck of it."

Oh but Tazman brings up a good point about removing old silcone. Alcohol doesn't do anything to dissolve silicone so don't use it, it just adds risk of killing fish as he said. Cured silicone can only be removed by scraping it off diligently with a razor blade. There may be solvents out there that can dissolve it, but again this is out of the question near fish. Make absolute sure you scrape off ALL of the old silicone because the new silicone will not bond properly to the surfaces if there's some remnants of the old silicone left on it.
 
#19 ·
I missed the pictures earlier..oops :)

I really suspect that piece has been added later as it is a lot wider than most tank manufactures use for bracing. A thin strip of glass / plastic is all that is needed not a pane like piece that size.
 
#20 · (Edited)
All I can say is... maybe. Hard to say without taking measurements and actually seeing if there's a problem with bowing. OP, if you're feeling adventurous and want to contribute to science, try carefully and VERY gradually filling the tank and measure the amount of bowing in the middle as you add little amounts of water - take a tape measure, measure the outside edges of the glass from back to front, and then take the same measurement in the middle. As in, add a bit of water, take a measurement, and if the bowing is still just a millimeter or two, continue adding water bit by bit. Stop adding water obviously if the bowing starts to get worrying! I don't know if there's something similar in the US, but after doing some painstaking research for my own tank, I learned that there's a German industry standard that says the glass is allowed to bow up to a maximum of 1/500 of the length of the glass - so if the front pane is 1 m long, it can bow out up to 2 mm. In my case, after removing the OEM braces like an idiot, the bowing was certainly exceeding this guideline, and so I had to DIY a good solution - now the bowing is well under this limit and I can sleep soundly at night. Oh and I'll add this was for a 30 gallon tank, much smaller than than OP's.
 
#21 ·
Ok you know what, you might be right that's it's not original, there's a near identical case in the middle of this page I posted before, talking about a 55 gallon with a broken glass brace:
FAQs on Glass Aquarium Repair, Braces/Cross Supports

The advice given there is that the brace is not proper because it's being fastened to a piece of plastic, rather than being attached properly to the glass - as I mentioned before, silicone joints are best when it's glass being attached to glass. So hmmm maybe this was a poorly executed DIY brace in the first place, but since there IS a brace that was put in, I would suspect highly that there was a reason for it being put there, not just for looks or for another purpose like supporting a lamp or something.
 
#23 ·
Can you please answer the following:

1. At present, how much wider is the distance between front and back panes in the middle of the tank, compared with at the sides where they meet the side panes? Surely you've got a tape measure or a yardstick or something to measure with.

2. Are the glass braces siliconed to the front and back glass panes directly (hard to tell from the photos), or are they attached only to the plastic frame?

3. Can you confirm again that you bought this aquarium in a pet or aquarium store, and the glass brace was in place when you first got it?
 
#24 ·
1. At present, how much wider is the distance between front and back panes in the middle of the tank, compared with at the sides where they meet the side panes? Surely you've got a tape measure or a yardstick or something to measure with. Left: 13 and 6/16 inches, Middle: 13 and 9/16 inches, Right: 13 and 6/16 inches. That is from the outside of one side of the frame to the outside of the opposite side along the top of the tank.

2. Are the glass braces siliconed to the front and back glass panes directly (hard to tell from the photos), or are they attached only to the plastic frame? Yes the glass brace is siliconed directly to the glass side panes just under the top frame.

3. Can you confirm again that you bought this aquarium in a pet or aquarium store, and the glass brace was in place when you first got it? it was puchased from an aquarium store in Portland Oregan as is. It had not been altered in any way. I do not remember the name of the store, sorry.
 
#25 ·
The brace on my planted tank is 10 inches by 18 by 3/8 and I presume that the thickness of my brace is due to my aquarium having its 2 front corners cut off to created a 3 panel front view and made to support the weight that is no longer being handled by right angle corners. The poster said he bought it unaltered and brand new 12 years ago at a pet store and since its name brand All Glass Aquarium the pet store wouldn't have had any reason to add an extra brace.

Using alcohol is to help the new silicon adhere to the glass, if you buy a tube read the directions - Its to clean the micro particles off the glass, unless you go drenching the area then the tiny amount you would use to wipe the area clean wont be enough to harm your fish. Also alcohol evaporates at room temp very quickly so in the 24hrs you let your silicon dry any remnants will be long gone.
 
#26 ·
OK. Then we've established that a) the bracing mechanism is, beyond reasonable doubt, genuine (built by professionals) and b) the professionals deemed it necessary to put in a big glass cross brace. Also as is, with the tank less than half full and a broken brace, there is 3/16 inches of bowing happening, which is above the upper limit of what I'd personally feel comfortable with. I might even consider lowering the water level a few more inches for peace of mind. You really need to get a replacement piece of glass cut ASAP and replace it in the exact same position as the original, making sure to remove all traces of the old silicone before applying any fresh silicone.
 
#27 ·
I will dafinatly be getting the brace made and replaced a.s.a.p.! I will go ahead and lower the water a bit farther, I got a back up filter for it that goes to 40 gallons and it can work in as little as 6" of water, though I don't think I will need to bring it that far down. I will show you guys pics after I get it repaired.
 
#28 ·
The only caveat is that we have to bring down the water enough that there's virtually no bowing occuring before siliconing the new brace into place, or we'd have to clamp the outer glass panes from the outside to pull them back into place, which is definitely less ideal and more risky.

As we've established, it's already bowing a significant amount at 3/16 inches, so it's not really feasible to try to put in a brace as-is. The optimal situation from the point of view of the tank's integrity would be where you could move your fish to another tank for a day, allowing you to perform the fix when the glass is fully unloaded and empty of water. Maybe you can leave a very minimal amount of water at the bottom to keep the filter running somehow, as long as it's so little water that it doesn't cause measurable bowing.

This of course has the unwanted effect of stressing your fish by moving them about a lot - I don't know if this is too great a risk for the lives of the fish, maybe somebody can pipe in here and offer further ideas.
 
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