Danno, that sounds about right. And the material I got from him courtesy of their scrap box was 6061 in either T4 or T6 temper.

Either way a lot of the temper was restored even after just two days. Likely the restoration is on a exponential curve sort of basis where the first part of the return is quick while the last bit takes a while.


For those wondering the actual annealing is good for any sort of work hardened aluminium. While much of the last couple of posts has been about the aircraft sheet metal I also had good luck with straigtening forged aluminium clutch levers using the same carbon and anneal process. I've done three levers using this method now and all worked well for as long as I owned the bikes afterwards.

I also used this trick while workng on making an aluminium bowl from some .050 alloy to try out some autobody metal forming hammers. I was able to hammer stretch the metal into a mixing bowl like form of about 6 inches diameter by 2 inches deep using the hammers and some soft wood as an anvil. I carboned and re-annealed the metal twice during this process.