Re-sealing a leaking tank

[gonefishing]

I am looking for any tricks, tips and suggestions to avoid potential pitfalls of re-sealing a large aquarium.

Recently I rescued a used 135 gallon tank (48" L x 24" D x 31" H) that was headed for the landfill. I noticed the tank sitting outside a garage in my neighborhood. One evening the owner was outside and I stopped by to ask what his plans were for the tank and he said that he was going to throw it away and asked if I wanted it.

He said that it has a slow drip from one of the corners and would need to be re-sealed with silicone. Also the center cross member that supports the hood is missing. It probably was broken out by someone trying to use it as a handle.

I brought the tank home and have cleaned it up. Other than the leak and missing cross member, the tank is in great shape with no visible scratches.

I have begun the tedious task of removing the old silicone sealant using straight edged razor blades. My understanding is that the glass should be perfectly clean before applying new silicone.

If anyone has had any experience with this type of project and would be kind enough to share any advice, I would be very greatful.

[SCOTT]

Re: Re-sealing a leaking tank

With the setup I have, being all reclaimed tanks of one form or another, I do alot of resealing. The easiest method I have found is to use the straight edged razor blades to completely remover the old silicone as well as any buildup which may be present that just wont come off no matter how hard you scrub it. Once I have the glass as clean as I can possibly get it, I then use either amonia or rubbing alcohol to clean the area. This removes any oil film, dirt, sediment, whatever which may be left behind from the old silicone. The amonia and alcohol both evaporate quickly, leaving a squeaky clean surface to bond to. I personally use GE silicone 1 for all my tank repairs. The advantage to this is its low cost and ease of use. With the caulk gun loaded with a tube of silicone, get in there and press it tightly into the seam and put in a nice tight bead, forcing as much into the joint as you can. You will need to work fairly quickly as the silicone will begin to form a skin after just a few minutes. Once you have the bead laid down, you will need to go back in and smooth it to form the familiar curved shape. You can use a plastic baggie over your hand, rubber gloves, whatever you preffer to keep the silicone off, but you will need to spread the silicone with your finger to get the curved seal. Don't worry to much about getting the silicone all over the place, this will happen your first few times doing this. Once the silicone begins to set up you can take the straight blade back in and clean up your exposed line on the front glass, just be carefull not to disturb the seal by cleaning to close to the joint. On a 100 gallon tank I would leave at least 3/4 of an inch overlap to ensure a good seal. The more of an overlap you leave, the less likely the silicone is to seperate from the glass and blow out your new seal. Once you have it looking good, allow it to set up for 48 hours to hard cure, then rinse and fill. Ideally you will want to fill the tank outside and let sit for a few days, just to make sure you have a good seal, but thats up to you and your confidence in the job you did. As for the cross brace, you can go to a glass store and have a piece cut to fit. The procedures will be the same as for the seal.

[Ellen]

Re: Re-sealing a leaking tank

I've never done it, but I was going to. A cool tip I heard was to have a shotglass with alcohol in it sitting in the tank. That way, you can run the silicone with the caulk gun, then immediately dip your finger in the alcohol and run it along the seal. Its quick, and you don't really have to stop everything to get the nice curved seal, just dip your finger in the alcohol, run it along the seam, and continue silicone-ing. If you're only doing the one seam, I guess it wouldn't make too much of a difference though...

HTH,
Ellen

[Obed]

Re: Re-sealing a leaking tank

I agree with everything Scott said, I have done the same thing many times. I use a gasket removing tool, looks like a curved toothpick and after I have the glass scraped with a straight edge razor, I take the tool and get as much old silicone as I can out of the space between the two glass pieces that form the corners or bottom seam. I use aquarium grade silicone in the tube that fits caulking guns and run a bead around all the seams and then use either my finger or cut a piece of plastic at an angle so that it touches both panels of glass but leaves a gap in the corner and smooth out the silicone so that you get one continuous seal on all surfaces. I would never seal just one joint, leaves room for water to get between joints and leak. Leaving the tank alone for 48 hours to make sure it is well cured is an absolute must. Then like Scott suggested I would fill it outside and let it set for a day or two just to make sure of the seal.

[SCOTT]

Re: Re-sealing a leaking tank

A shot glass with alcohol in the tank, why do I get the impression that it wouldn't be my fingers getting wet? Of course, with enough shotglasses, the leak just wouldn't seem all that important anymore now would it? The hell with them fish, they can fend for themselves![/i]

[Ellen]

Re: Re-sealing a leaking tank

:drinker: LOL, rubbing alcohol peoples!

[MultiFry]

Re: Re-sealing a leaking tank

Scott has some great input.

Here's how i do it:

- only use GE silicone 1 in the tube with a caulk gun

- have ready a box of latex gloves, roll of paper towels, a some plastic spoons.

- after removing and cleaning, apply masking tape 1/4" - 1/2" from each corner on inside.  use enough tape to where you have about 2" sticking over the top.

- put on the latex gloves. cut the GE silicone 1 tube at a angle.  try for a 45 angle, doesn't have to be perfect - it just helps when laying down the silicone.

- start the silicone bead at the top of the tank, perpendicular to the corner (try not to give either side of the corner preference).  placing the silicone tube nozzle in the top corner, slowly crank the caulk gun till just enough starts to come out the tube.  While slowly cranking the caulk gun (about a crank per inch or two), push the silicone bead to the bottom corner.  you can allow a very small portion of silicone bead to overlap tape.

- take the plastic spoon w/ bottom round side facing silicone, and place on bottom corner.  pull the spoon up at consistant angle to top corner.  (you can use your finger with the gloves, just put on new gloves after you smooth the bead.)

- pull masking tape off ASAP (do not allow silicone to sit on tape for more than a minute or two).  put spoon on a paper towel, discard (use a new spoon on the next corner)

- word to the wise: work fast, maybe 3-5 minutes starting when you lay down the silicone.   repeat process per corner.  if you get any extra silicone on the glass where you don't want it, just wait for it to dry then remove w/ razor blade.

hope this might help.

[SCOTT]

Re: Re-sealing a leaking tank

I have used the tape before, personally, I preffer to do it without, but to each his own. I love the spoon idea tho. Also, with the larger tanks, 75 and up, a larger spacing on the tape ie more room for the silicone to adhere to the glass would be a good idea. The more surface area for the silicone to bond to, the stronger the seal is going to be.

[rjam]

Re: Re-sealing a leaking tank

I just did 100% of the silicon for my 135 and the best advice I can give you is use plenty of razors. they dull fast. I let mine sit for 7 days to cure fully and have absolutley no leaks, You can do it!!! I ordered my "Aquarium" caulk from and online supplier, I could not find any that was "Fish Safe" at Home Depot, in the larger tubes anyway.

Be persistant, get all of the old off you can, i used automotive picks to even get the old out between the cracks. It is alot of work but alot cheaper than having to redo it. Chances are you will not get 100% of it but as much as you can.

[Tiapan]

Re: Re-sealing a leaking tank

i just started working on an old oceanic flat back hex, i have all the silicone cut out and am gonna seal tommorow morning, glad to know someone else uses GE silicone one cus thats what i bought. so i will see how it goes and will let all of you know if I get it right. i had also seen the shot glass of rubbing alcohol on another site so there might be merit to it after all. hey and a beer while working is always nice lol

[Tiapan]

Re: Re-sealing a leaking tank

i did it, with armthehomeless's help we resealed the 60 and it held water for a full 24 without any sine of a leak or airbubble in the silicone, Scott you were right, its not the absolute prettiest but it looks good enough for my first time resealing, now if just got to set it up.

[SOULJAA]

Any Suggestions???

What's up everyone. I really need some help and guidance from you guys!!!! I have this tank that I picked up from a garage sale a while back. Well to make a long story short...It leaks from (what looks like) 3 of the 4 bottom corners. The tank dimensions are: 36.5L x 18.5W x 17"H.

1st question: what size is the tank?

I've tried 2 maybe 3 times since rescuing the tank to seal it w/ aquarium silicone, which after reading you guys past suggestions and step-by-step plans, I now see that I wasn't doing nothing more than wasting silicone by "patching" the leaks from inside of the tank. So it has become more than obvious that I'm not doing something right and really need to make an effort to porperly seal the tank.

2nd question: How might I go about getting the woodgrain trim off of the bottom of the tank w/o damaging it (both the tank and trim)?

3rd question: Where can I get some of the GE Silicone 1 from (since that seems to be the choice of the experts)?

I got to admit...I'm kinda of nervous to undertake this project b/c I really don't want to mess nothing up. I guess that's why I've been "half-assin'" around w/ the "patches". But I would imagine my apprehension is understandable. So w/ that said, can ya'll help a brother out?!?!!!!! :bshelp:

[Mzungu]

Re: Re-sealing a leaking tank

NO idea about the sealing part, but your tank looks to be about 50 gallons.(In the calculation I was using, it came to 49.76.)

[Ellen]

Re: Re-sealing a leaking tank

1) Here's a nifty tank volume calculator: http://www.angelfish.net/tankvolcalc.php

If those are the outside dimensions and the tank has .25" thick glass, it'll hold 48 gallons, if it has .5" glass, it'll hold 46 gallons.

2) I dunno.

3) I think you can get it at a home improvement store.

HTH a little,
Ellen

[Ellen]

Re: Re-sealing a leaking tank

Mzungu! Again with the ninja-posting!  

Ellen