I wasn't sure which category to put this thread in so I put it in two. I am currently in the process of trying to reseal a tank. This is my first time doing this and I have read a lot of post on here about it and I have watched a few videos on youtube. I have been removing the old silicone from the tank and the sides were pretty easy, but on the bottom of the tank I removed some silicone, but it appears that the bottom pane of glass is made shorter than the footprint of the tank and is surrounded by silicone. I don't know if that is a good enough explanation, but I will add some pictures later. From what I have learned researching is that I can strip just the silicone that is holding in the water and not the silicone that is actually holding the tank together. The silicone that is around the bottom pane appears that if I remove it that the pane will possibly come out. From the pictures and videos I have seen it doesn't seem like this set up is common, do I have an unusual aquarium? Should I take that silicone out? Any advice will be greatly appreciated.
Help!!!! First time resealing a tank!!!
- Thread starter D Realist
- Start date
I've encounterd tanks where the bottom pane is almost a quarter inch short where it met one of the sides. The interior seal had obviosly been resealed before and had a reocurring leak. In these cases i prefer to completely disassemble tank so i can center the bottom to split the difference of the gap then reseal. Is the tank already leaking or is it as a precaution?
It is already leaking. There is a gap on all of the sides, but it is bigger on the front side of the tank than the other sides. Do I have to dig the silicone out of the gaps? Now I am getting really nervous about this and am starting to think this was a bad idea.
I always leave the old silicon in the gaps and just clean off the sealing silicon. So if you had a razor blade and slid it along the bottom of the glass and cut into the silicon until you hit the side glass panel. Go all the way along the base cutting into all four sides. Then on the side glass pieces run the razor straight down until you hit the previous cut part, don't go deeper into the silicon and cut to far. All the old silicon should come up in a couple pieces. Go back over the glass area that was covered with the silicon and get it as clean as possible. I use acetone with a cloth on the very last cleaning.
Adding the silicon is the easy part. I use silicon 1 from Home Depot in a calk gun. Run a 1/4 inch bead along the bottom and up the 4 corners. Wet a finger and spread the silicon so half the bead goes on each glass panel. I try to do this all in one step.
Let dry 5 days to a week - this is the hardest part
Adding the silicon is the easy part. I use silicon 1 from Home Depot in a calk gun. Run a 1/4 inch bead along the bottom and up the 4 corners. Wet a finger and spread the silicon so half the bead goes on each glass panel. I try to do this all in one step.
Let dry 5 days to a week - this is the hardest part
View attachment 826738
This is a picture of the bottom of the tank. As you can see the bottom pane of glass is separated by some space and silicone from the side pane. That is the biggest gap which is the front side of glass, but there is a gap all around. What can't be seen in the picture is that that space of silicone is level with the glass, if not a little lower than the glass. It is like a grove or ditch is there and the silicone is down in there. I believe this tank is an older tank, and it is a large tall tank.
This is a picture of the bottom of the tank. As you can see the bottom pane of glass is separated by some space and silicone from the side pane. That is the biggest gap which is the front side of glass, but there is a gap all around. What can't be seen in the picture is that that space of silicone is level with the glass, if not a little lower than the glass. It is like a grove or ditch is there and the silicone is down in there. I believe this tank is an older tank, and it is a large tall tank.
Hello; Here is a link to a video that may be helpful in sealing a leak
http://www.youtube.com/watch?v=XKactsdPpO8&feature=channel_video_title
http://www.youtube.com/watch?v=XKactsdPpO8&feature=channel_video_title
Hello; Here is a revised old post about sealing a tank with silicone. Resealing a tank can be a chore and may not work the first time, but if you get a good seal it should last for years.
I have found that trying to run a line of silicone only on a portion of a tank has often not worked out very well. If a tank leaks, I find it best to reseal all the corners and sides at the same time.
-(In my experience the silicone needs to be applied in all corners and sides while it is still tacky so that it will bond to itself at the apex of each side.)
-(New silicone does not seem to bond to old silicone very well)(Some have posted that it will stick better to the old if the old is well cleaned, I have yet to test this myself.)
I also cut out the existing silicone with a utility knife from all corners before trying to seal with new stuff. I find a shop vacuum a handy way to remove the bits of silicone. If the first application of new silicone does not seal the leak, I cut out all the silicone that I have just applied and seal the whole thing again. I also find that the silicone tubes that fit in a caulking gun to be the handy way to apply silicone. The tubes of silicone that you squeeze with your fingers are just too hard for me to control and I have not tried to use them in years. You can plug the end of a big tube of silicone with a nail or something round to keep it from curing too quickly, as you may need it again.
-(Note – When you cut the end of a silicone tube, make the first cut near the end so as to have a small opening. You can always cutoff a little bit more if the bead of silicone is too small.)
Some additional pointers. I usually give a tank a good cleaning before applying the new silicone. I use a paste made from ordinary table salt (Without iodine) and a soft sponge.
-(I do not use a sponge or cloth that has been used with soap or chemicals.)
-(I have buckets and sponges that are used only for my tanks.)
The salt paste does not scratch glass and does a fair job at removing the deposits from the surface of the glass (be sure the sponge or cloth used to apply the paste with is not coarse enough to scratch the glass on its own and watch for bits of gravel that seem to jump into the salt paste.) (Letting the salt paste dry to a haze should desiccate most critters if you want to disinfect a diseased tank.)(Note- wetting the glass will soften up the deposits somewhat.) (Also for stubborn mineral deposits, a razor blade in a holder that gives a firm grip is useful. Use a shallow the angle on the blade and keep an eye on the corners of the blade. The corners sometimes get bent and will scratch a thin line. Rinse the salt paste out and let the tank dry well.
Once the tank is clean, I think it needs to be very dry before applying a bead of new silicone. Dampness tends to hide in the very small seams and in the corners of a tank. I suspect that dampness prevents the silicone from bonding properly to a surface and may result in a leak in a good looking seam. It can take a while for the moisture to dry out of the small seams.
(note- this is not real critical, but try to have the tank in a place where it can sit for a day once the silicone has been applied, so you do not have to move it until the stuff can cure some. Silicone labels often say that it will cure enough in two days to add water. (While I have gotten away with around a two day cure with thin beads in small tanks it has not always worked. It seems prudent to wait a few more days to be sure. Some experienced people have suggested seven days for a full cure.) Thicker beads of silicone in large tanks will likely take the additional time to cure. Silicone will skin over and harden from the outside in. Push on a thick part of a bead with your finger to see if it feels firm and solid.
If you manage to lay down a decent bead of silicone try to resist poking at it in an attempt to smooth out a bump or irregular spot. I usually only try to smooth out the glob where the corners meet at an apex. You may get away with wetting your finger tip lightly with water and gently touch it. (Water on the outside of a joint should not cause a problem if you use just enough to dampen the tip of the finger and not enough to drip off.)(Does it sound like fun yet?). You will want several paper towels or cloths handy to keep the silicone wiped from your fingers. It will get on everything if you don’t and it is a real pain to clean off. If you use a cloth to wipe silicone the stuff does not come out, so do not use a favorite towel
If you happen to mess up and need to clean up a smear,( and find that the more you wipe it, the more it smears.) it may be easier to let the silicone set up for a day or two so that it is no longer gooey. It can then be rubbed off with a cloth or your fingers.
I try to test the tank in a place where a leak or having to empty the tank will not be a problem. I also allow a resealed tank to sit full of water for a few days to be sure the tank does not leak before moving it into the house. This may not be wise or practical with a large tank as moving may open up a seam. Good luck with whatever procedure you decide to use.
I have found that trying to run a line of silicone only on a portion of a tank has often not worked out very well. If a tank leaks, I find it best to reseal all the corners and sides at the same time.
-(In my experience the silicone needs to be applied in all corners and sides while it is still tacky so that it will bond to itself at the apex of each side.)
-(New silicone does not seem to bond to old silicone very well)(Some have posted that it will stick better to the old if the old is well cleaned, I have yet to test this myself.)
I also cut out the existing silicone with a utility knife from all corners before trying to seal with new stuff. I find a shop vacuum a handy way to remove the bits of silicone. If the first application of new silicone does not seal the leak, I cut out all the silicone that I have just applied and seal the whole thing again. I also find that the silicone tubes that fit in a caulking gun to be the handy way to apply silicone. The tubes of silicone that you squeeze with your fingers are just too hard for me to control and I have not tried to use them in years. You can plug the end of a big tube of silicone with a nail or something round to keep it from curing too quickly, as you may need it again.
-(Note – When you cut the end of a silicone tube, make the first cut near the end so as to have a small opening. You can always cutoff a little bit more if the bead of silicone is too small.)
Some additional pointers. I usually give a tank a good cleaning before applying the new silicone. I use a paste made from ordinary table salt (Without iodine) and a soft sponge.
-(I do not use a sponge or cloth that has been used with soap or chemicals.)
-(I have buckets and sponges that are used only for my tanks.)
The salt paste does not scratch glass and does a fair job at removing the deposits from the surface of the glass (be sure the sponge or cloth used to apply the paste with is not coarse enough to scratch the glass on its own and watch for bits of gravel that seem to jump into the salt paste.) (Letting the salt paste dry to a haze should desiccate most critters if you want to disinfect a diseased tank.)(Note- wetting the glass will soften up the deposits somewhat.) (Also for stubborn mineral deposits, a razor blade in a holder that gives a firm grip is useful. Use a shallow the angle on the blade and keep an eye on the corners of the blade. The corners sometimes get bent and will scratch a thin line. Rinse the salt paste out and let the tank dry well.
Once the tank is clean, I think it needs to be very dry before applying a bead of new silicone. Dampness tends to hide in the very small seams and in the corners of a tank. I suspect that dampness prevents the silicone from bonding properly to a surface and may result in a leak in a good looking seam. It can take a while for the moisture to dry out of the small seams.
(note- this is not real critical, but try to have the tank in a place where it can sit for a day once the silicone has been applied, so you do not have to move it until the stuff can cure some. Silicone labels often say that it will cure enough in two days to add water. (While I have gotten away with around a two day cure with thin beads in small tanks it has not always worked. It seems prudent to wait a few more days to be sure. Some experienced people have suggested seven days for a full cure.) Thicker beads of silicone in large tanks will likely take the additional time to cure. Silicone will skin over and harden from the outside in. Push on a thick part of a bead with your finger to see if it feels firm and solid.
If you manage to lay down a decent bead of silicone try to resist poking at it in an attempt to smooth out a bump or irregular spot. I usually only try to smooth out the glob where the corners meet at an apex. You may get away with wetting your finger tip lightly with water and gently touch it. (Water on the outside of a joint should not cause a problem if you use just enough to dampen the tip of the finger and not enough to drip off.)(Does it sound like fun yet?). You will want several paper towels or cloths handy to keep the silicone wiped from your fingers. It will get on everything if you don’t and it is a real pain to clean off. If you use a cloth to wipe silicone the stuff does not come out, so do not use a favorite towel
If you happen to mess up and need to clean up a smear,( and find that the more you wipe it, the more it smears.) it may be easier to let the silicone set up for a day or two so that it is no longer gooey. It can then be rubbed off with a cloth or your fingers.
I try to test the tank in a place where a leak or having to empty the tank will not be a problem. I also allow a resealed tank to sit full of water for a few days to be sure the tank does not leak before moving it into the house. This may not be wise or practical with a large tank as moving may open up a seam. Good luck with whatever procedure you decide to use.
That is one of the videos I watched. I have all the equipment that he has in the video. For some reason my bottom is constructed differently than the one on the video. His on the video is setup like most tanks where the sides and the bottom meet in the corner, my bottom pane doesn't meet the side panes, instead there is silicone wedged in between the bottom and the sides.
Hello; Sounds like you are describing a larger than usual gap between the ends of the glass panes. While this may be so, I suspect there is going to be some gap that the silicone must seal on all tanks. The most likely issue that comes to mind is the potential for damaging the glass edge when removing the old silicone. Also if the gap is way out of spec it may be possible to cut all the way thru the old silicone at those points.
I do not recall if you posted that the tank in question is factory or homemade. A factory tank with such a gap may have other issues.
As a guess it should be possible to seal such a gap. I have done similar seals on cracked breeder tanks or non display tanks wher I put a glass panel over the cracked panel and did not care how it looked.
You may want to be extra sure to clean as much old silicone and residue film as is possible to help insure a good adheasion with the new silicone. I have also found that the new silicone job results are usually best if the stuff can be applied in one setting to all seams while it is still tacky. You will also perhaps be much better server to allow extra time for the thicker beads of silicone to cure.
good luck.