Re:
(1) Of course, my point was about the confusion surrounding the term "silver solder." I didn't say that low-temperature solders had any use for frame building; obviously they don't.
(2) 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...
Steve Maas Long Beach, California
Richard M Sachs wrote:
> replying to...
> snipped:
> Steve Maas <smaas@nonlintec.com> writes:
> 1)"There are also manufacturers of silver-containing solders,
> having melting points around 600F, which they also call "silver solder."
> and
> 2) "Somewhere I read that the older Columbus tubes were limited in
> brazing temperatures to about 1300F (sorry if this isn't accurate;
> going by memory here, always dangerous); obviously, they had
> to be silver brazed, and there was quite a narrow range between
> melting the brazing alloy and overheating the joint. (I don't know
> if this is true of modern tubes.) Perhaps this could shed some light
> on the earlier discussion of frame cracking after rough use."
>
>
> 1) yeah-but that's not applicable to bicycle framemaking.
> jewelry maybe. not bicycles...
> 2) in spite of that information being part of Columbus'
> speeeil (sp?) since the 60s, i'd lay odds that more than
> 99% of the frames built during that era were brassed
> brazed. that 'warning' from Columbus reminds me of
> the instructions on shampoo bottles: shampoo. rinse.
> and shampoo <again>.
> e-RICHIE
> chester, ct
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