AJS & Matchless Owners Club

East Suffolk Section

Technical Tip (8): Annealing aluminium

Annealing Aluminium
The way to anneal copper head gaskets to make them suitable for re-use is generally known.
(Heat to cherry red, then quench, the opposite to annealing steel, which you cool naturally in the air)
Although it’s usually soft, if you have to bend aluminium sheet up to make something, what is not so well-known is that to make it more workable, you can anneal that too. Since this metal melts at a lowish temperature, care must be taken. Here is how to find the correct temperature.
(This may best be done when she’s out or you’ll cop it for making a mess and wasting soap!)
Soften a bar of soap in water and wipe the aluminium over with the paste that forms on it. When you heat the metal and the paste turns black and bubbles, stop heating immediately – that’s the correct heat.
Leave the metal to cool slowly in the air.