At 8:16 PM -0400 7/1/02, NortonMarg@aol.com wrote:
>It is the tubing in the heat affected zone (joint) that moves. It's all glued
>together and equally weak, so it's hard to say exactly what is moving.
What I think you're describing is annealing, refereed to sometimes as "cooking the tubes" for the layman, and is used to allow the grain structure of the metal to return to the state it was in before it was formed into tubing. The after affects of annealing is "softer" and more "brittle" tube. Usually you would anneal something to work it or cut it easier. Most of my experience is using it to work copper, brass, and aluminum before cold working the metal. As I understand it annealing happens with steel between 1400-1800 degrees. This would explain why it happens more in brass brazed frames. Are there an material engineers on the list who can give us the low down.? ciao, Brandon"monkeyman"Ives