Instructables
Picture of Vegetable gardens from old water tank

When a 23,000 litre (5,000 gallon) water tank starts to rust you end up with a big object to dispose of. It is heavy, it is awkward to handle, it is a dead weight that is always in the way.

We mulled over what to do with ours for a long time before inspiration struck. Vegetable gardens, just like those over-priced ones you see in the gardening centre!

We had a cute idea with concentric circles of garden beds which sounded exciting until we realised that any attempt to bend corrugated iron wouldn't work and would be a waste of time.

I have to acknowledge that my wife had the idea we finally went with: to cut the tank into sections and rejoin them.

This is how we turned our old water tank into 6 boat shaped vegetable garden beds.

 
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Step 1: Dismantling the tank - remove the top

The obvious first step was to dismantle the old tank. Sounds easy but these things are strong. They are designed to hold 23 tonnes of water without leaking. So there are lots of screws and loads of glue.

This tank was about 1.8m tall, 3 metres in diameter and built from 3 rows of corrugated iron. There was a lid on the top and a obviously a bottom that needed to be removed. These were soldered or welded to the sides. I bought a pack of 10 grinder cutting wheels since I knew they were going to get chewed up.

We got off to a bad start. I removed the entire top row with the lid attached, with the idea of pushing it off and then cutting it apart. This was the point where I realised they are big and heavy and awkward and it ended up stuck and twisted and wonky.

In retrospect I would have worked my way around the top cutting off the lid and letting it fall down inside, then removing the top row of iron.

waynevanwijk7 months ago

Sow sow sow your boat ...

If you are worried about the sides bulging out under the pressure of the dirt you can run a threaded rod through through the middle, across the beam. I have a few heavy duty stainless ones here if you want to collect them. Another hint is to cut a slit along a length of cheap irrigation pipe and slot it over the top exposed edge of the iron. This is then held in place with cable ties.

Microbe (author)  waynevanwijk7 months ago
Thanks Wayne, not at all worried about the bulging (at this point) and had the threaded rod idea in mind.

As for jagged edges, the tops aren't too bad as they aren't cut edges. But rather than irrigation pipe, hang out at the tip and pick up some garden hose.

Glad you are not worried but I am sure that I heard Sheila saying something about you having too much bulge in the middle.

Spidie7 months ago

Great use of space Steve - I've seen people make them out of the full circles, but they are too big and impractical to get to the stuff in the middle. The boat shape is awesome.

Microbe (author)  Spidie7 months ago

Thanks, yes that was why we thought about concentric circles early in the process, but as I said bending the iron so it could fit inside another piece just wouldn't work.

tstimpson17 months ago
I like the idea, another option for shape of the beds could be wavy: alternating the curve each direction, and then having a parallel wavy panel on the other side. But only if you wanted an entire wall of vegetable bed.
Microbe (author)  tstimpson17 months ago

Yes that's a nice idea too.

rimar20007 months ago

Clever recycling!

emilkaram7 months ago
Very beautiful