# sealing drilled holes in a tank



## discipleak (Nov 30, 2008)

I obtained a big tank that has two holes drilled in the bottom of the tank. I want to seal the holes for the time being. I may make use of them in the future but for the time being I want to waterproof the tank. Any suggestions?


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## Ed (Sep 19, 2004)

If they are bulkheaded then the easiest method (so you can use it again in the future if you wish) is to first determine if the bulkhead is threaded or not. If it is threaded you need to get a threaded pvc connector for which you can cut a small section of pvc which is then capped allowing it to hold water. 
If it isn't threaded you will need to make as tight a fit as possible with a piece of capped pvc and check for leaks by tightly dry fitting the pvc. 

Or you can plumb in from the bottom of the bulkhead and include a ball valve if you ever want to drain water easily. 

Ed


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## Alpha Pro Breeders (Oct 13, 2008)

Cut a piece of glass large enough to cover the hole, then silicone all the way around it. Wait at least 24 hours before messing with it, and make sure you use the silicone in a well ventilated space, and away from any frogs.


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## stingfrog (Apr 1, 2007)

Using the siliconed glass method works well. I have used it numerous on aquariums to seal holes and when the glass has cracked across a corner. None ever leaked on me.


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## Ed (Sep 19, 2004)

It does work well but if you want to use the holes again, it isn't the easiest method to remove... 

Ed


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## Jellyman (Mar 6, 2006)

I've sealed several holes using a piece or glass approx 2" larger then the diameter of the hole. If you decide in the future you want to use the hole simply use a putty knife and work it under the glass to pop off the piece of glass.


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## Jason DeSantis (Feb 2, 2006)

You can also use a thick piece of plexiglass. Its much easier to remove in the futre then glass is.
J


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## Occidentalis (Jul 11, 2009)

Jason DeSantis said:


> You can also use a thick piece of plexiglass. Its much easier to remove in the futre then glass is.
> J


You can drill it easier too, if you want to do double thickness for the bulkhead.


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## Ed (Sep 19, 2004)

This is assuming that it doesn't have bulkheads already in place.. if it does then those have to be removed before the glass/plexi can be glued down. If bulkheads are in place then a piece of pvc either plumbed above or below is a simple fix and can be unscrewed or popped out in the case of a good dry fit and its ready to go. 

Ed


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## burky (Jan 22, 2007)

Occidentalis said:


> You can drill it easier too, if you want to do double thickness for the bulkhead.


The silicone will not hold the plexi. It will not stick the plexi to the glass. the best way i think is using silicone and glass. When you want to remove it you just have to go through the silicone with a utility knife.


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## Occidentalis (Jul 11, 2009)

burky said:


> The silicone will not hold the plexi. It will not stick the plexi to the glass. the best way i think is using silicone and glass. When you want to remove it you just have to go through the silicone with a utility knife.


It seems Jason and I have access to magic silicone that adheres to acrylic as well. 

Glass would be a stronger bond, granted, but acrylic and polycarbonate have worked for me in the past. We aren't trying to hold back 400 gallons of water here, just patch a hole (perhaps temporarily)


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## discipleak (Nov 30, 2008)

Thanks for the responses. The holes arent threaded, and I thought about siliconing a piece of glass on top of it.


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## Ed (Sep 19, 2004)

The holes aren't threaded but there is a bulkhead in place right? 

Ed


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