# Forum Home Renovation General Odds & Sods  Leaking concrete tank

## JB

Tried patching from the outside with limited success. Believe an internal treatment (preferably just adding something to the water) works better. Can anyone help  or direct me to a forum where this sort of issue is discussed?

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## rrobor

If you can get into the tank its easy, there is a bitumen paint designed for metal tanks which Im sure would work on concrete its cheap and has a suggested life of 20 years. I think you are looking for a radweld sort of product I doubt that exists, after all it would do the Dutch lad out of a  job.

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## JB

Emptying the tank and climbing in out of the question, for various reasons. I don't know what a radweld product is...I'm sure something can be added to the water that seeps into the cracks...just don't know what.

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## SilentButDeadly

I've been playing with Mr Crystal over the last couple of years on our concrete tank with varying levels of success...works quite well on the smaller stuff but not so great where the joins are moving a bit.  Still.....it is worth a play.  Especially when you follow the instructions. 
Adding 'stuff' to the water won't work and it will make the water taste and feel crook. 
You can get a poly liner made up too.  But it's expensive but still cheaper than a new tank

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## Ronaldo451

I had a similar problem with a 30,000 litre concrete water tank that cracked during the Newcastle earthquake. Tried all sorts of things to patch it from the outside without success, ended up having to do it from the inside. 
What you want sounds similar to how Bars Leaks works with car radiators - as the solution is exposed to the air it sets and (hopefully) blocks the crack....unfortunately this takes a fairly thick mixture to work and is only effective on small, intermittently weeping fractures. This is a bit hit and miss in a small system like a car radiator which is under a lot of pressure and heat - in a large water tank would have no chance. 
How wide is the crack and does it extend all the way down the side of the tank? I have seen repairs on small areas where they plate it from the inside. This is done  by drilling a hole and pull a stud through with a metal plate on the inside (like a large washer) covered in bituminous compound which is then tightened with a nut on the outside. More trouble was an alternative of wide metal bands all the way around the tank tightened up on the opposite side of the crack like a big hose clip.

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