DIY reseal 200 gallon

I bought a 200 gallon aquarium and it leaks. so I cut out all the old silicone. used GE silicone I to reseal it. let it cure for 24 hrs and filled my tank. The front bottom seal cracked out along the whole length of the glass. My question is does the actual aquarium silicone have a higher tensile strength than the GE stuff? I read online that lots of people use the GE stuff to seal their tanks but mostly less than 100 gallons. when the seal busted it broke the wooden support loose from the bottom should I add more braces or is the silicone alone supposed to hold the tank together?

 

Hello Rick,

I've never resealed a tank myself but here is a link you may find helpful:

Best of luck! Keep us posted please.

Ken

 

well I got it resealed it held water for about 10 min or so then I cracked out, so maybe I just didnt put a thick enough coat of silicone or like I say maybe the GE silicone just isn't good enough to hold up to the 1600LBS of water on top of it. whereas an actual aquarium silicone is. just trying to gather info since I have enough of the GE stuff left to seal it again, and if its just that the frame is supposed to hold some of the weight than after I repair the frame it should be fine. trying to get a game plan together so next weekend I can get aquarium silicone if need be and go for round two

 

If your taking it all the way apart are you making sure the old silicone is all completely off? I've read on hear somewhere that if the old isn't completely off it will fail and I'm thinking it said the only way to get the old off was to use rubbing alcohol.

Anyway just thought I'd ask, have you searched this site for other people that have done it?

Couldn't tell you a thing about tensile strength of GE silicone, I kinda of figured aquarium silicone was just 100% silicone and that's it. I would give it 48 hours or more to cure on such a big tank IMO.

 

I didnt take it all the way apart I just redid the inside seal, and I got all of the old silicone off with rubbing alcohol. and yeah that was my other thought was that it need to cure longer than the 24hrs that GE claimed

 

Did you put it on pretty thick, I think the joints on a 200G have a lot more silicone than a regular tank. Just trying to remember if the last 200G I saw had like a 1 inch wide joint or greater, might want to google it couldn't tell you for sure. Good Luck.

 

that's what I figured was that there couldnt be much of a difference because any additives to improve the strength may effect it being fish-friendly. So I geuss I will try again after fixing the brace and use a thicker coat of the GE stuff, and probably allow a week before testing again since the thicker coat will surely take longer to cure. and hopefully that will get the job done, since it obviously held at one time with just the one brace underneath.

 

Hello

I had similar problem and this worked for me:


I can tell it works for 60g, but 200 gallon is a big difference...

A product that for sure will seal your tank is 3M 5200. It is used this to seal thru-hulls on most size boats, so for sure it can handle any tank size. I see 2 problems with it:

1)Not sure if it is safe for aquarium fish. I have been using on boat's bait/live wells for years and I can't really see a difference on bait survival rate on wells with the sealant vis a vis the ones without it. However, a tank is completly different, so, again I am not sure.
2) It only comes in white, black and tan; not in clear color as far as I know. So it will be visible.

Hopefully someone haviing sealed a big tank in the past can give you a finall solution. If not at least this are 2 possible options.
Good luck

 

And yes in my experience you want to apply a generous layer and to give the finish with some plastic thingy (or thumb) by applying pressure so the sealant penetrates between the 2 sheets.

 

I had fixed several tanks including replacing full glass pieces and it depends on how big is the tank. A pretty good rule is that the thickness of the silicone needs to be at least the same as the glass. The finger method or the spoon method to get a good penetration on a tank this size don't work. The seem needs to be thick and a plastic spoon won't cut it. May want to try a piece of plastic like an old milk jug trim to get a good angle will work.

 

ok well I will make me a deal to smooth the silicone to be thicker cause last time I did just use my fingers I didnt really think the silicone held all the weight. should have done a little better research beforehand. I got the silicone stripped off again so friday when I get paid I can buy some more silicone and a brace of some sort to fix where the frame came apart. and try again hopefully with better luck.

 

Hello,

I would also recommend letting it cure for at least 48 hours. Too, you may try to find one of these tools at your local hardware store:


Good luck and keep us posted.
Ken

 

Hello,

I would also recommend letting it cure for at least 48 hours. Too, you may try to find one of these tools at your local hardware store:


Good luck and keep us posted.
Ken

Ken I really have to say that the link shows the right tool for the job but in a way small scale. This will work on tanks up to around 50 gal but not for a 200 gal. Is way too small.

 

Thanks for letting me know Navy

Ken

 

should I cut the front piece of glass completely out since it seperated from the bottom piece? I don't think I can get the old silicone out from between them without taking it out

 

When I resealed tanks I don't take the glass out unless I'm replacing sides. Some tanks got some tiny little disk that work as spacers so the silicone can get in there but I have seen so many new ones that don't have anything. I would leave it just like that and clean it really good take as much stuff as you can and use alcohol to go over it and scrape off any residue of silicone rub alcohol again let it dry and seal.

 

very good replies thanks to share

 

ok so I don't know if anyone will still reply to this since its so old but I finally went round two with my tank and I got it to hold the weight of the water. it just has a leak in one corner so my question is how imperative is it that I remove all of the silicone and start over? can I get away with just smearing some more silicone on that one corner and it seal? cause its a ton of work scraping off all of the old silicone on this size of a tank not to mention the cost of another round of silicone. as of right now it drips about once every 3-4 seconds. not that I think that makes any difference I think its more of a whether or not the new silicone will create a water tight seal against the already cured silicone. another question is that since it claims to be water safe after 24 hours fully cured after 24 if I put 4-5 inches of water in the tank after 12 hours if it might compress it into the spot that its leaking allowing it to cure with no leak? I'm about ready to give up on it and take it to a pro the only problem is I don't think there's anyone close by that does this kind of thing. Srry about the length just need a lot of info cause I'm at my wits end and ready to give up but its so a beautiful tank compared to my current 120 gallon. I really want it to work. plus I picked it up for only $200 so ive got some leeway on the cost of repair to make it cost efficient vs a non project tank this size.

 

ok so I don't know if anyone will still reply to this since its so old but I finally went round two with my tank and I got it to hold the weight of the water. it just has a leak in one corner so my question is how imperative is it that I remove all of the silicone and start over? can I get away with just smearing some more silicone on that one corner and it seal? cause its a ton of work scraping off all of the old silicone on this size of a tank not to mention the cost of another round of silicone. as of right now it drips about once every 3-4 seconds. not that I think that makes any difference I think its more of a whether or not the new silicone will create a water tight seal against the already cured silicone. another question is that since it claims to be water safe after 24 hours fully cured after 24 if I put 4-5 inches of water in the tank after 12 hours if it might compress it into the spot that its leaking allowing it to cure with no leak? I'm about ready to give up on it and take it to a pro the only problem is I don't think there's anyone close by that does this kind of thing. Srry about the length just need a lot of info cause I'm at my wits end and ready to give up but its so a beautiful tank compared to my current 120 gallon. I really want it to work. plus I picked it up for only $200 so ive got some leeway on the cost of repair to make it cost efficient vs a non project tank this size.

Sorry You had so many issues with this tank but to tell you the truth all the old silicone has to come off. The new sealant won't adhere as well as to plain glass. I had an issue like that and involve dropping the water to about 1 inch of the rI'm since I didn't remove the silicone around the rI'm the new silicone didn't work well with the old one around the rI'm and the water sipped behind the new sealant and made it worst later on. So I had to remove all of it again. How thick are you laying the silicone around the walls and bottom of the tank? Silicone cures with air. By putting water you are just stopping curing process and it will leak again if you put water at 12 hours. I have one question for you. You said you are using silicone that cures in 24 hrs on my opinion no pure silicone cures like that. All my tanks that I have re-sealed I leave them 3 to 4 days to fully cure. Dap makes a great product 100% silicone. I have gotten some other brands that if you use them in hI temp areas or colder they just don't work. Well hope this works for ya.
Good Luck.

 

I'm using the GE Silicone I and it claims to be fully cured after 24hrs but I did leave it 3 days before trying it and I'm putting it on really thick now. I cut a pattern to make it 1/2". o well I geuss ill be stripping off silicone again this weekend and going to home depot and gettin more silicone

 

You mean you made like a template to smooth it out while still wet? Because you can't cut it after is dry. If you are cutting it after cured that is your problem.

 

yeah I cut a piece of cardboard to use to shape and smooth it while it was wet.