Re-sealing old tanks

Alien Anna

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Hi,
a friend has bought a 2nd hand tank that has turned out to be leaking at the corners. I've got some aquatic silicone sealant on order. Is there anything we need to know before we try to repair the tank? I'm concerned that it isn't going to be as easy as we thought. By the looks of it, the previous owner tried to repair the tank as there is an enormous glob of sealant in the corner that is leaking.

(NB: I've only applied sealant to a bath-tub before, and that wasn't terribly successful!)
 
Hi Anna,

I have used the aquatic sealant before to do the same thing, to be honest it was pretty much straight-forward. Though the corner where the large glob of sealant is will probably need the existing sealant stripping off.

I personally would strip the sealant completely from the corner area where it is leaking and then add the new sealant.
 
How bad is the leak? It could be as simple as just triming the sealant around the corner and re-sealing to striping down one side and sealing the whole bit again. If it's a small leak you should get away with trimming around the leak and re-sealing.
 
It's a pretty bad leak, actually (about 2mm hole), and I can't be certain, but I think the other corner also has a slight leak. I'm not sure how much to trim back - whether I should do the whole tank, the whole bottom of the tank, or just the bits near the corners. At some point, it is unavoidable to have new silicon touching the old silicon.
 
best thing is use a stanely blade or a scalple and trim to 2 cm away from where the hole is. being in the corner it's gonna be fiddley. try not to remove the sealer from where the glass joins unless it comes away naturaly(ie don't put the blade between two bits of glass) then re~cover where you have removed the sealer. this should do the trick. If it doesn't it may have to be striped down and completely realsealed. Someone else may have another sugestion but this is the method I've been using. best not to make to much work for yourself unless it's absolutely necisery(sp?)
 
OK if the tank is already leaking (which you say it is) then i would suggest completely resiliconing all of the upright joints (vertical ones) as there is a risk that if you only repair the leaking area that other areas will begin leaking :what:

I have had a 3 foot tank split on me before and it nearly killed an 18" Snakehead in the process :but: so i definately wouldnt take the risk and would resilicone all the upright joints to be sure.

Its not at all difficult and all you will need is............

Aquarium silicone
Masking tape
Pure alchohol
Stanley blades or razor blades
Jug of warm soapy water

And patience lol

Firstly strip off the old silicone with a blade and then clean with the pure alcholhol the areas requiring resealing

then apply the masking tape to either side of the repair area so as to get a nice straight edge to the silicone..........apply the silicone in one smooth slow movement, leave for 5 mins to start setting and then dip a finger into the warm soapy water and run it along the fresh repair to give a nice smooth finish to the silicone then after a further 10 mins remove the masking tape carefully to reveal a nice smooth bead of silicone that looks as good as when the manufacturer made the tank ;) 8)

This is the best way i have found for repairing tanks and ive tried most believe me lol :p

Hope this helps :D ;)
 
Soapy water??? Isnt soap one of those things you DON'T want in your tank or are the aliens talking again. 8)
 
Im with you Rose i though any houshold cleaning aids were a no no for your tank

Having re read the post i cant imagine a fingers worth of warm soapy water would do much damage, but can you not just water?
 
You could try but the silicone will stick to your finger and rip off!! :what:

Plus add to this the fact that a resiliconed tank should not be used for fish for at least 2 weeks after repair (due to the silicone still leaching out chemicals) and that you should be filling and draining the tank every 3 days to remove these toxins and i dont see the problem with using a mild soapy water mix as it will all be gone by the time your ready to put fish in the tank :p

And how dare you question my authority on this matter!!!!!!! :angry: :grumpy:

J/K lmfao any more questions please post and i'll be happy to answer lol ;) :p :laugh: :hehe: :laugh: :hehe: :blush:
 
Ok everyone here it is...
I am in the middle of re-sealing a 90 gallon and a 135 gallon tank.

First the 90...I thought pretty staright forward...WRONG!! After stripping all the internal silicone (this is a absolute necessity due to silicone WILL NOT stick to itself) I found out I had a bigger problem. The seam that was leaking was due to the joint was seperated. This means taking the one side of glass completely off, cleaning all edges of old silicone and re-siliconing the joint. Then putting the glass back on and then re-siliconing all the internal seams. After many razor cuts and scraped fingers this tank is now ready to be put back together.

The 135:

Same problem only this tank is old...VERY OLD...so I will probably take it completely apart and redo the whole tank.

Now some may say is it worth it? Well for smaller tanks I would say no it's not, but for larger tanks that sell for upwards of $300.00 and up, it sure is.

One more note: It is absolutley safe to use acetone to clean the old silicone off the tank. Use a single edge razor blade to get the majority of it off first. Then the acetone to get any remaining film and any oils from your hands.

Not only will silicone not stick to itself, but if there is any oily residue on the glass it won't bond properly.

HTH
 
Does anyone else othe than me ever marvel at the fact that a little silicone sealer will hold half inch thick or more glass together? It is like an evil covalent bond to me, just waiting to separate.. :)
 
well, that answers that question....thank you for teaching me your ways O wise Wizard :hehe:
 
i often look at my tank and wonder how the silicone can
hold the glass together with the vast volume of the water,
it's truely marvolus stuff. :thumbs: :music:
 
Talking of truely marvelous stuff time for another "JD" smoothie I think.
 

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