At 11:50 PM 10/18/05 +0100, you wrote: >There would seem to be two lessons here: 1) Don't quench boilers. I fail to see how this conclusion can be drawn from a few isolated cases of cracking. In years of reading I can never recall a single cautionary reference to quenching and I've quenched nearly 100 copper boilers and never had a crack, but then I've never used anything but new silver solder from a known source. Quenching serves a useful purpose. >2) Only buy the best I can completely agree with this. Boilers are no place to skimp on materials. Regards, Harry MODEL ENGINEERING DISCUSSION LIST. To UNSUBSCRIBE from this list, send a blank email to, modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the subject line.