The steel tubing retains more of it's pre-brazed tensile strength post-brazing. Less chance of accidentally over-heating things and getting unacceptable grain growth as well.
Greg Parker Ann Arbor, Michigan
Date: Fri, 23 Sep 2005 11:15:19 -0700 From: Kurt Sperry <haxixe@gmail.com> To: "brianbaylis@juno.com" <brianbaylis@juno.com> Cc: fred_rednor@yahoo.com Cc: OROBOYZ@aol.com Cc: classicrendezvous@bikelist.org Subject: Re: [CR]Spectrum frame and brazing Better in what empirical, quantifiable as opposed to theoretical sense? I understand the theoretical advantages of silver brazing. Is there any measurable or demonstrable objective difference between brass brazed and silver brazed framesets all else equal? Kurt Sperry Bellingham WA
On 9/23/05, brianbaylis@juno.com <brianbaylis@juno.com> wrote:
>
> Dale,
>
> Silver brazing of frame tubes is clearly better for the tubing. The fact that brass brazing doesn't actually destroy the frame is a non-issue in my mind. The only people building custom frames with brass are the ones who
experienced difficulties with silver from improper use early on in their experience, and instead of figuring out how to use it decided to use brass because it does not require the same amount of care and attention in the cleaning and assembly process. That is why factory built bikes are brazed
with brass; they don't want to take the time to clean and fit the parts more precisely.
>
> Sure, brass works. Silver is better.
>
> Brian Baylis
> La Mesa, CA
> Debate? I don't think so.
>
> -- OROBOYZ@aol.com wrote:
> In a message dated 9/22/2005 11:13:52 PM Eastern Daylight Time,
> fred_rednor@yahoo.com writes:
>
> << I might be mistaken but it looks as though Tom Kellog use both silver and bronze brazing rods on this frame. The rear dropout areas appear to be attached using bronze rod (which "fills" better) whereas most of the other
joints appear to have been done with silver rod. Is that truly the case? >>
>
To which Dale replied:
> Sure!
> Virtually all modern USA custom builders have done that.. the brass fills the big voids at the drop out ends and, the theory goes, is less of a heat issue there 'cause the parts are so chunky.
> Silver is used the rest of the joints because the gaps are so close and you have thin stuff to deal with which, the theory continues, would be otherwise be damaged by the higher heat that brass requires.
> As you may infer from my phraseology, some pooh pooh all that heat build up stuff and point to the Euro builders who have built a zillion bikes with brass and suffer relatively no failures due to apparent overheating. The debate rages on.....
>
> Dale Brown
> Greensboro, NC USA