Cistern (PE plastic) cracked. Repair possible?

Hello,

I have a 3,300l rainwater tank made of PE plastic in the garden (built in 1998). Unfortunately, the garden has settled by about 3cm in the front area (the rainwater downpipe was dismantled for several months due to external work).

Due to the settling of the ground, the cistern has kinked and is cracked on both sides in the lower area.

Is it possible to repair the leak from the inside? Replacing the tank is unfortunately not an option.

Thank you very much

I would be skeptical now. Maybe there is a swimming pool builder near you who can install a durable liner with a suitable adhesive?

For damaged sewer pipes, for example, resin-impregnated "plastic hoses" are blown in. These are then cured under constant air pressure. It may also be possible to have a "bubble" built for this purpose. However, the last prices I remember being charged for such operations were, well, no bargains ops:

There are plastic welding rods. There are also those specifically made as PE plastic. These are also used on car and boat bodies. I don’t know if they are used for such larger damages as well. Maybe call a manufacturer sometime. Orbi-Tech would be one, for example. You have to approach the damage with a soldering iron. If a repair is possible, it would probably cost around 150-200€. Afterwards, you could also sell the device again.

Thank you for your responses!

I had also thought about pond liner. It could even be feasible since the liner does not have to be cut for pipe penetrations, etc.

There is pond liner made of PE plastic. I could weld this in the upper area of the cistern. PE on PE should hopefully hold.
I would straighten the area around the crack and cover it with protective fleece.

Does that sound feasible?

Yes, that sounds quite good. Perhaps you can also glue/weld the sheet not only at the top area but entirely at the edges with the [Zisterne].