Weekend Workshop

Build an aluminium melting furnace and create moulds for £30

Cast your own components.

elting aluminium and pouring it into moulds sounds like an ambitious thing to attempt in your shed. However, it’s cheaper and easier than you might think. With little more than a trip to a DIY store and a day-or-two of simple fabrication, you can give yourself the capability to melt and form aluminium safely and successfully. In this feature, we’ll show you how to create a small furnace, mix sand and build the wooden frames into which the sand is packed (the cope and drag). Next issue, we’ll fire up the furnace and demonstrate casting techniques.

Melting and pouring the aluminium is relatively easy. Making a good mould is the tricky bit – and the more complex the shape you’re trying to cast, the trickier it becomes.

MHollow shapes require cores to be added to the mould, which is a little more advanced than what we’ll be demonstrating here. Search online for home casting videos and you’ll find people who have refined this basic technique to create castings as complex as crankcases and cylinder barrels for motorcycle engines.

We suggest starting with something much simpler. We’ve chosen to replicate a door handle from a 1934 Armstrongsiddeley 20hp tourer. We have an original to use as a pattern. If we didn’t, then we’d have to make a pattern out of wood or – perhaps – have one 3D printed.

The range of automotive items you can cast easily at home will be limited more by your imagination than your equipment – consider badges and emblems, trim strips, light fittings, bezels, bosses, brackets, knobs, or even thermostat housings and fuel filler caps. With patience, aluminium can be polished to an almost chrome-like finish. Be aware of its limitations, though – it won’t do the load-bearing job that cast iron or forged steel is meant to do.