How to make a magnetic hourglass

I was in Waterstones over Christmas and in their gifty section, they had a magnetic hourglass that looked pretty cool; essentially, a regular hourglass with some sort of ferrous “sand” and a magnetic in the base. However, it was £20, which seemed kind of expensive for something that would just sit on my desk, so I decided to make my own for far less cost.

I went through a few iterations before I found something that worked reasonably well. I initially tried using plastic champagne flutes from poundland (the ones with the detachable bases). I figured I could drill a hole through the stems of two flutes, attached them together and just cap the ends. However, the stems were too thin to get a firm (or straight) join, so I abandoned that plan pretty quickly.

Next (and this is where I started taking pictures), I tried a couple of small jars, separated by a disc with a hole in it. (The disc was just laminated card – nothing special.)
I didn’t really expect this to be a great solution, but I wanted proof that the iron filings I got off eBay and the magnet I got off the fridge would produce the intended effect.

It actually wasn’t a terrible result. The biggest issue was that the join was too wide and flat – I had to overload the hourglass to ensure that enough filings would fall through and there was a lot left in the top bulb. Still, the principle was sound.

My next thought was to use small cones in the join, instead of a flat disc. However, joining them presented similar issues to joining the champagne flutes (not straight, not stable) and I also wasn’t sure that they would bear the weight of the upper bulb.

I then went back to my previous version, but using vessels with much narrower necks. I settled on some plastic bottles for holding bath products (80p each in the supermarket), joined with a much smaller disc. (I just glued the bottles onto the disc one at a time – it’s fairly sturdy.)
This works pretty well – almost all the filings fall through and a quick shake before turning sends the rest down.

To create a base, I simply melted a couple of tea lights into a tealight holder and pressed a fridge magnet into it.

The final result is a neat little craft project, which cost about £4, plus a couple of things that were lying around the house.
Take that Waterstones!

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3 Responses to How to make a magnetic hourglass

  1. Luke says:

    This is such a cool project. How well did it work as an hourglass afterwards?

    • thatgiantman says:

      It’s definitely more of a desk toy than an actual timer. That said, the only real variables are the size of the hole and the amount of iron filings – with a little bit of trial and error, I reckon you could make a reasonably accurate one-minute timer.

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