Re: [CR]Was: Rene Herse Bicycles Now: using differing braze joining materials.

(Example: Component Manufacturers:Chater-Lea)

Date: Sun, 23 Sep 2007 17:56:20 -0500
To: classicrendezvous@bikelist.org
Subject: Re: [CR]Was: Rene Herse Bicycles Now: using differing braze joining materials.
References: <s6f63d2b.028@gw15.hofstra.edu>
In-Reply-To:
From: "John Thompson" <johndthompson@gmail.com>


Edward Albert wrote:
> I am certainly NOT an expert on frame building techniques, however, I
> have always been under the impression that silver "soldering" allowed
> for cooler temperatures and thus less overheating of tubes. That,
> however, is not the point of this post. The heating issue aside, in my
> research on the U.S. frame builder Dick Power I found that the American
> builders of the 1930's and 40's, especially Drysdale and probably Pop
> Brennan, all used brass. Dick Power switched to using silver sometime
> in the very late 40's or, more likely, around 1951. He did so in spite
> of the fact that silver was considerably more expensive in that you
> could buy brass by the pound very cheaply because it resulted in less
> clean up of the finished frame. It was easier to remove excess silver
> brazing material than is was to remove brass. Now, Dick was not artiste
> by any means, and his frames show it. But I wonder if this was, in
> general, one of the reasons that silver became the material of choice
> over brass. And, did it in fact make for an easier clean up?

If you know what you are doing, it is entirely possible to silver braze a joint and not need to do any cleanup beyond removing the flux with hot water. A good quality silver flows exactly where you want it to flow and without leaving blobs or pools of material behind. This is much trickier with brass, which often pools out at the point where you apply the rod, and doesn't flow under the joint as nicely meaning that you need to apply the rod in several areas around the joint. With silver you can often feed the rod in at one point and use the flame to pull the silver throughout the joint. This not only minimizes cleanup, but also assures you that the joint is indeed fully penetrated with brazing material with no void areas.

--
John Thompson (john@os2.dhs.org)
Appleton WI USA