snipped: smaas@nonlintec.com wrrote: "This brings up a more interesting question: what are specifications such as a maximum temperature based on? I'd like to think that the people making these tubes have some metallurgical knowledge, and the 1300F limit (or whatever it was) had some validity. On the other hand, maybe it was conservatively specified, in the expectation that some duffers would be pretty heavy with the torch. Or, maybe much higher temperatures were OK if limited to a short period of time. Or.....? Anyone have any insight on this? Among 750 list members, we should have a materials guy or two..."
i'm not a materials guy. but i've seen all types of frames built frames
built with all types of methods. irrepective of what the tube suppliers
say about 'proper care and handling', my experience is that there's
a different set of rules on the other side of the counter. that is, most
guys 1) get it hotter, and 2) keep it hot for longer periods, and 3)
don't
abide by the clearances suggested, and 4) don't subscribe to the
'warning labels' that are offered up by the mill supplying the pipes.
technique, not technology, or somesuch phrase, best describes
the situation we're discussing here.
e-RICHIE
chester, ct