Posted by John Swensen on December 23, 1999 at 15:13:21:
In Reply to: Re: Re: Re: Re: Re: Re: Re: Cerveny 693 vs ST.Petersburg.HELP!!!!!!! posted by Joe Baker on December 22, 1999 at 20:27:22:
Re: "unannealing" brass
The only way to harden brass is by working it, which usually means bending it or squeezing it down on a hardened mandrel with a spinning tool. I have heard peripheral references to work hardening by vibration (eg. a coil of half-hard copper in the back of a plumbing truck gets hard and brittle over the years), but I have been unable to locate any technical references to using vibration as a hardening method; it would be nice to set the bell of a tuba facing a woofer playing frequency sweeps at a high volume for a few days to harden and protect it, however...