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FAQs on Glass Aquarium Repair, Techniques

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Related FAQs: Glass Aquarium Repair 1, Glass Aquarium Repair 2, G lass Aquarium Repair 3, Glass Aquarium Repair 4, Glass Aquarium Repair 5,  & FAQs on Repairing Glass Tank: Scratches/Blemishes, Cross-Braces, Leaks, Chips/Cracks, Whole Panes, Tools: Cutting Glass, Silicone, Moulding/Frames; Olde Tank (Slate Bottom, Metal Frame, Pecora...) Repairs, Troubleshooting/Repairs, & Acrylic Aquarium RepairUsed Aquarium Gear

Mmm, you can buy or build clamps to hold all in relative position... Or use wood clamps... I use strips of strapping tape most of the time myself. RMF

Accidentally cut into seam between glass while resealing an aquarium      9/1/19
Hello! I found your site and it looks amazing.
I purchased a 80 gallon glass aquarium that was used for turtles/reptiles.
<DO check whether this was/is a tank "just made" for such; i.e. NOT intended to be filled with water fully (to the top); such tanks are made of much thinner glass. This 80, depending on height, out to be 3/8" thick plus>
I read the silicone can harbor pathogens, plus the storage and age of the tank are unknown, so I decided to reseal it.
<Good move>
I purchased Momentive RTV 108 silicone and scraped and used acetone to remove the silicone from the seams of the tank.
<The excess, remaining Silicone I'll take it, after removing the bulk of corner seam material w/ razor blades>
I realize now I was aggressive with the razor blade and was unaware of paying attention to the seams and most likely cut into the seams. As far as I can tell they look fine, but I am afraid of this leaking when I reseal and bring it inside. (Yes I will fill test outside first.)
I then read about rebuilding a tank as a way to fix the seams I may have damaged. I am worried about this process, that I may fail to do this correctly.
<Only way to tell... is to test>
What is my best course of action at this point? Should I seal with the silicone and presume to not need to fix what may not be broken (no, I do not want a new 'pool room.') Or do I recognize that the risk is too great and attempt to rebuild the tank?
<I'd test fill it out doors... the garage let's say, on a stand and surface making it level and planar>
The tank does have the glass brace across the top, and the plastic 'oak colored' frame on the top and bottom. At this point I have not tried to remove the frame- I wasn't planning on it with a reseal only.
<I wouldn't remove this frame>
Also, I'm having a heck of a time getting all the silicone off the plastic frame, though I have nicked the frame a few times trying to get it off.
I'm wondering how critical that part is (the top frame.) With the exception of me potentially slicing into the glass seam with the razorblades, the glass looks good with the silicone removed.
<Such frames are mainly for looks and assembling the tank... the bracing is important though.>
I suppose I should ask how I can tell if I have gone into the seam and how far I've gone and when is it bad enough to rebuild vs. reseam?
<Again, I wouldn't panic. Have seen modern, custom tanks w/ such seams cut into entirely... on purpose; demonstrating the strength, integrity of corner beads/seams>
Thank you so much for your time and valuable knowledge, I do wish I had figured this part out ahead of time.
<What two word phrase did the late Doug Adams popularize? "Don't Panic!".
Cheers, Bob Fenner>
Re: accidentally cut into seam between glass while resealing an aquarium    9/2/19
Hello Bob-
<Hey ya Les!>
Thank you so much for your wisdom and amazingly fast response. I will make use of the Donate to site button!
<Well, don't know about wisdom... friends and I have studied and studied; have some knowledge, little intelligence... and we're hopeful for wisdom!
Cheers, BobF>

leaking tank. Silicone use f'  11/1/11
WWM Crew -
I recently acquired a 65 gallon aquarium. It is basically a 55 gallon with a flat back, hexagon shape in the front. The tank is an Oceanic and is about 10-15 years old.
<A good manufacturer I'd warrant>
I filled it with water and it had no leaks, so I drained it and moved it to the position where it would be set up. When I filled it for the second time, with 45lbs of rock at the bottom this time, the silicone gave way on the top hex section on the right side from the top down. The plastic trim on the top seems to have come apart and the silicone gave way from the top to about 6" down. To say the least it was a mess. Here is my question, I want to undergo resealing the tank myself, but would like to only reseal the broken section as I do not trust myself to reseal the entire tank. Is it possible to reseal just the one vertical section?
<Mmm, yes; though better to cut away, replace all inner seams while you're at it>
I fear that the new silicone would not bond well when it meets the old silicone at the bottom.
<This is so... again best by far to trim away all (single edged razor blades), scrub residue w/ a solvent (as listed on WWM), and re-run a new continuous bead...>
In order to prevent another leak, I was considering running new silicone throughout the entire tank (very large bead) over the existing silicone in all the areas besides the broken section (this section would be scraped free of old silicone).
<Mmm, don't do this... as you've stated, the new won't adhere to the olde... and it will look... "funky"... a mess you'll be reminded of every time you look at or think of this system. Maybe have someone w/ experience show you "the ropes" w/ working Silastic... use a bead-placing tool... let cure for a day or more... trim off the excess. Not hard to do once you've been shown.>
I was ensure <unsure?> that the new bead of silicone around the entire tank meets the glass for a proper bond. Thoughts on this?
Blake Higgins
<You have mine... from many years, trials of doing this. Take your time here. Cheers, Bob Fenner>

Tank Repair Question - 4/21/07 Crew, <Hi Chris> I am fixing to repair a tank, and have a question for you.  What is the easiest way to remove the plastic trim from the top and bottom of the tank, so I can remove the broken glass and replace it.  Is there a type of solvent, or will this just "pop" off with enough force.  I don't want to break it. <I'd use a single edge razor or something similarly slim and sharp (maybe even a flexible sharpened putty knife) to slip up under the trim and free it from the silicon's grip, then gently pry off.>   Thanks, Chris Harris <You're welcome and good luck! -Lynn>

Aquarium Leak (Possibility For Catastrophic Failure?) -- 03/09/07 Hi there, <<Hello>> I hope you can help me out. <<I shall try>> We have a 140 gallon fish tank that is probably about 10years old.  Last night my dad noticed water droplets on the outside of the tank and thought it was nothing until he put his hand over to wipe it and it formed an even bigger droplet and started coming out in a very very fine stream (more like trickling down). <<Bad news indeed>> I've read your website but most of the questions concern leaks in the silicone sealing - the leak that we have is on the side panel of the fish tank and is the actual glass itself. <<Yeeikes!  I would drain this tank immediately for fear of catastrophic failure of the glass panel>> It is pretty much like someone stuck a pin right through the glass and caused a leak. <<Hmm...no youngsters (or oldsters) running around with BB-guns are there?>> Now what we don't understand is how it possibly could have happened and what to do? <<Can't say how it happened (likely something got knocked against the tank), but the tank will need to be drained and repaired/replaced>> My dad is looking for another tank right now but I want to know whether we can fix it with a piece of glass and silicone or just sealing that hole itself with silicone? <<'Patching' with a piece of glass 'might' be an option, though not often recommended...but simply trying to fill the hole with silicone is not.  Replacing the entire glass panel is the better/recommended option, but considering the age of the tank, perhaps simply replacing it makes the most sense here.  See if your local fish store/hobby friends can house your livestock while the new tank gets established>> My dad is also worried that the longer we leave the leak the worse the chances of it actually turning into a crack and leaking the whole basement. <<Worries me as well...depending on how low down on the panel the damage is, I can see the tank coming apart with a 'bang!'>> Should he be worried about that and what do you think is the best thing for us to do right now. <<Yes, be worried...and drain the tank...>> Thank you very much. An <<A pleasure to assist.  EricR>>

Resealing 137 gal tank I have resealed this tank 3 times now and I lost all my fish so now for the question. I need to take the panels apart and reset/reseal them, Do I need to C-clamp the glass in place while it's drying or is the weight of the glass enough to do the job? <The weight of the glass should do it> This tank is 6 feet long. The last time I sealed it I scraped all the silicon out, cleaned it using alcohol and installed new silicon. I wanted 36 hrs for it to dry and then refilled it with just water and waited 6 hrs with no leaks. I then emptied it, put in the black sand, rocks, plants, water and fish back in it. That night while I was asleep the bottom seam opened up and 1/2 the water dumped out into the living room!  I don't want to risk that again so I want to replace all the silicone.  It seems to me the glass would seal better if it were clamped tight while it was drying. What do you think???? <Too likely to break if uneven stress is put on. If you do use clamps, either make them wood, or insert something soft between them and the glass> This tank must weigh 250lbs empty! Should I use a 400 wet sand paper to ruff up the edges so the silicone will stick better? <No! The silicone will adhere to the clean glass (use toluene to clean the last bit off, and take care not to touch the cleaned surfaces with your hands, fingers. Bob Fenner> Thanks!

Old chromium frame tank repair I have a couple of Tanks that where my Grandmothers and they have a chrome finish around them, well just today I cracked the side panel is there anyone I can have it repaired, I love the vintage look they have and since they been in my family since the 50's is there anything I can do, if so money would be no object. Edward Reiman <Yes, this tank can be repaired... in a sense, updated. You need to have strong wrists and a sharp box cutter, you will cut out the present sealant and glass, get a new panel (from a hardware store likely) and silicone (100%) it and the old joints all the way around into the empty space. Bob Fenner>

Repair of 65Gal hex tank Hi.  I've just finished reading all the tank repair FAQ's currently posted and did not see this addressed.  I have a >20 year old 65 gallon hex glass tank . It's not made anymore so a replacement is not available. All the glass is fine. The tank has been used for salt water and fresh water. Over the years algae or bacteria have grown between the silicone seal and the glass, undermining the seals. Obviously it is starting to spring small leaks. I'd like to repair the tank. <Not hard to do> Several questions:  Are there specific braces to use to hold the necessary angles while the joints are caulked and curing? <There are corner and cross braces made for the carpentry field that can be used, but many folks find "reinforced tape" (like the types with "lines" in them that are the Dickens to cut through) work fine to hold the panels in place> If not, can one joint at a time be re-caulked or should the entire tank be dismantled at once? <If all needs to be done, should be done all at the same time. Build "upside down, with the bottom on top> How do I estimate how many tubes of silicone caulking I need so that I can have enough on hand? <Mmm, if done "properly" doesn't take much. Maybe buy two cartridges (10.5) ounce and take one back if un-used> I am especially concerned here as one of the faq's said old and new silicone won't bond even after only 24 hours. Parallel sides are 24 inches apart and the tank is 30 inches high.  <I remember this shape, size tank. Very attractive> Any suggestion on sequencing of the seams since there are the six joints around the hexagonal base glass and then the vertical joints between adjacent vertical panels. <Best to make like tightening the lug nuts on a tire, in roughly opposite arrangement, then bottom last> Thanks in advance for any help.  Laura <Do look, ask around if there is someone, perhaps through a local store or hobby club, who has done this re-sealing work recently. Much easier to "see" and do with a little help. Bob Fenner>

Re-siliconing glass tanks I've just read through your advice on re-sealing a tank and it was very useful and informative. However, I have one more silly question. If you remove all of the old silicone will the tank not fall apart? <Don't know if I'm following you here. If there is no sealant left... and you've necessarily (to remove the old silicone) removed the plastic frame, yes, the side, front and rear glass panels will not stay upright. Some folks use the "old" frame to hold the newly-cleaned glass pieces in place while re-sealing tanks... others use tape of various sorts or wood/corner clamps. Bob Fenner>

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