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How to fix a water leak from a poly rainwater tank?

amir47
Budding Contributor

How to fix a water leak from a poly rainwater tank?

Please help

Ifound 2 leaks on my poly rainwater tank, what is the best adhensive I can use to plug it ?

 

amir47_0-1643464158260.png

 

MitchellMc
Bunnings Team Member
Bunnings Team Member

Re: How to fix a water leak from a poly rainwater tank

Welcome to the Bunnings Workshop community @amir47. It's brilliant to have you join us and many thanks for your question about repairing a rainwater tank.


Have you tried anything previously, or is that how the tank usually looks? It just doesn't look particularly smooth in that area which isn't necessarily bad as the texture will give an epoxy a chance to stick to it. 

 

A plastic welder is the most appropriate way to repair a hole or crack in a poly tank. The hole/crack needs to be melted back together as not many products will stick to plastic. If you clean the area thoroughly with soapy water and then dry it, you can try some PC Products 57g PC Marine Epoxy Putty. It's a two-part product which you mix up and smear into the damaged area. If you manage to get it into the hole/crack, it could do a reasonable job of sealing it. I'd suggest you then paint over the exterior area with a product like Leak Seal.

 

Please let me know if you have any questions.

Mitchell

 

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amir47
Budding Contributor

Re: How to fix a water leak from a poly rainwater tank

Thanks Mitchell, much appreciated for your reply.

 

I managed to take a video today.

As you metioned "If you manage to get it into the hole/crack, it could do a reasonable job of sealing it", is that means I have to push the putty into the tank through cracks? As you can see, they are very fine cracks, so what should I do? Should I push the putty really hard, so it get into the cracks?

 

I went to the local Bunnings today, it seems  Rust-Oleum 240ml Crystal Clear LeakSeal Flexible Rubber Coating Sealer is out of stock.

Is there anything else I can use? How about Selleys 300g Roof and Gutter Silicone Waterproof Sealant? or Gripset Betta 1L Waterproofing Membrane Bitumen Rubber?

A million thanks

 

MitchellMc
Bunnings Team Member
Bunnings Team Member

Re: How to fix a water leak from a poly rainwater tank

Hi @amir47,

 

The issue is the water pressure behind the crack. Although it is a slight trickle of water, it will take some force to stop it permanently. How much water is in the tank?

 

The putty needs to be pushed firmly into the cracks and it looks like you might need to use some time of push stick if it is a confined area.

 

The Selleys Roof and Gutter Silicone won't seal an active leak. Potentially if you drained the tank and painted it on both sides of the crack, it might seal. Once again, a product like Gripset Betta 1L Waterproofing Membrane Bitumen Rubber would be best applied from the inside. Sealing a leak on the outside is like putting a bandaid on a leaking tap. It might stop it dripping periodically, but eventually, the water will find its way past.

 

You could try either of those products or Gorilla White 100mm x 3m Waterproof Patch & Seal Tape, but I'm not convinced they'll work.

 

Mitchell

 

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Re: How to fix a water leak from a poly rainwater tank

I'm new here.

Mitchell, so glad to find the discussion below and will follow it up

BTW this discussion above did not come up on the search here https://www.workshop.bunnings.com.au/t5/forums/searchpage/tab/message?advanced=false&allow_punctuati...

 

I want to ask you to comment on the fact that I can see this tank that is up to 25 years old has settled and dropped unevenly and I think that caused the split and leak.  Should I empty it and resettle it before repair?

 

Regarding plastic welding, does Bunnings recommend someone?

 

Perhaps I can upload an image later, but there is not much to see.

 

Paul 

MitchellMc
Bunnings Team Member
Bunnings Team Member

Re: How to fix a water leak from a poly rainwater tank

Welcome to the Bunnings Workshop community @paultonson. It's brilliant to have you join us, and many thanks for your question about repairing a rainwater tank.

 

You'll find this discussion a bit further down the page as the sixth search result or the third result if you search "rainwater tank leak". However, many thanks for your feedback, as we're always looking to improve our member's experience.

 

If there is any indication that the split is on a location that could be stressed due to the subsidence, then I would advise you to empty the tank before re-levelling. However, if the split isn't on a stressed point and the subsidence has halted, you could potentially fashion a repair. Regardless I think it's a better long-term solution if you address the tank's foundation before completing the repair.

 

You might like to look towards websites like hipages to employ the services of someone that can complete a welded repair on your tank. Alternatively, if you ordered a Kinchrome plastic welding kit through our Special Orders, I trust our members would be excited to assist whilst you completed the repair.

 

Please let me know if you have further questions.

 

Mitchell

 

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