Help!! How long does silicone take to cure

[DaveSpivey]

Woke up at 4 am to find that dreaded stream of water coming from the tank on my kitchen floor. The silicone sprung a leak so I emptied the tank half way into buckets (thank god I moved recently and had 10 Home Depot buckets around) and applied silicone aquarium sealant on the inside and outside of that area.

The silicone says it take 24 hours to fully dry - does it really take that long. I need to get that water back in there as soon as possible.

Thanks,
Dave

[SPasse]

Dave,

There are a lot of variables including ambient temperature, thickness of the newly applied silicon, air flow etc.

But I am afraid to say that 24 hours might actually be a minimum.

Silicon “skins over� in an hour but has little strength until about the 24-hour mark. When I used to built tanks (large ones) I waited 7 days before filling the tanks as thick silicon seams take longer than 24 hours to fully cure.

Finally, I would identify the root cause of your leak. If parts of the seam are under undue stress or have other issues, you could be setting yourself up for a catastrophic seam failure. Surface applied silicon doesn’t add much to the strength of a seam.

How big of a tank are we talking about?

Regards,

Scott

[seasquirt]

All of the silicone sealant I've used said on the package that it takes 48 hours to completely cure, and not to refill the aquarium before that. I think the stuff also gives off acetic acid (vinegar) when it cures, so you might experience a pH shift if you fill the tank up before it is done curing.

[DaveSpivey]

Its just a 45 gallon corner reef tank. The tank is about 10 years old, and the silicone has been chipped away over the years from cleaning the glass. The rest of the silicone looks ok and I think by patching it from the inside, I will be ok - we'll see when I refill it tonight!

Thanks for the quick replies!
-Dave

[Kenzy]

I use a "GE" brand of silicone. On the label it says it will cure in 24 hours, but further down on the label it states " for aquarium use allow 3-5 days before filling". 45g is a lot to risk dumping onto the floor, I would give it a couple of days if possible before refilling.

[SAT]

Recently I wasted a lot of silicone attempting to make a gasket between two pieces of glass. I would cover one piece with Saran Wrap, put silicone on the other piece, then push them together. The idea is once the silicone dries I can pull the glass apart (which is possible because silicone won't stick well to Saran Wrap), and have a decent gasket.

Anyway, the first time I waited 72 hours before pulling it apart. The silicone had a 1/8 inch "skin" on it around the perimeter... but inside it was all still goop. No good. Eventually I waited two weeks and it was dry enough... still some goo in the middle but I could wipe that away and the gasket still worked.

I recently purchased a custom 300G tank. The maker said he always waits 3 weeks for the silicone to cure before moving the tank or filling it with water. Now I understand why.

Moral of the story? A glop sitting in open air will dry in 48 hours or less. Silicone sandwiched between glass takes a lot longer. If all you're doing is plugging a little hole, which doesn't require much strength, that doesn't matter. If you're trying to hold a large aquarium together, give it plenty of time.

[DaveSpivey]

Thanks All!

I applied a thin layer of silicone to the inside and a thin layer to the outside where the leak was. Its not the prettiest job, but will hold for a while. I ended up waiting 30 hours - it wasn't 100% cured, but the seal doesn't carry any stress - just plugs the hole basically. Anyway, I decided to replace the tank with the 54 gallon curved front corner tank - great excuse to go ahead with the switch!

-Dave