Re: [CR]Aircraft Welding on Rene Herse Frames?

(Example: Production Builders:Cinelli)

From: <hersefan@comcast.net>
To: <Classicrendezvous@bikelist.org>
Subject: Re: [CR]Aircraft Welding on Rene Herse Frames?
Date: Mon, 12 Jul 2004 17:09:23 +0000


Well sort of..... Some old frames such as Rene Herse and Alex Singer had handmade lugs which were made by (I'm pretty sure anyway) gas welding. Tubing was cut, mitered, gas welded together, then reamed out and cut, and voila - a lug or bb shell. This was often done when custom angles or sizes were needed. The reason that such welding works on these parts but would be a dissaster on a lightweight frame is that the material is different. For welding, a mild steel is used. Steels with higher carbon content become brittle (actually when cooled, the damage of overheating really occurs on the cooling side of things). Mike Kone in Boulder Colorado


-------------- Original message --------------


> David Benson brings up an important point to consider - in the thirties it was a

\r?\n> standard process to flame weld the various types of tubing that were used in

\r?\n> aircraft construction. A filler rod was employed and the results could be very

\r?\n> nice indeed - depending on the skill of the welder, of course. I discovered this

\r?\n> in an old book on aircraft welding from @ the late 1930's, or maybe it was the

\r?\n> WW2 era. If I recall correctly, the gas of choice was a Hydrogen/Oxygen mix at

\r?\n> low pressures. Like many welding processes it was not easy to master, and the

\r?\n> problems with getting a reliable joint to survive aviation service is what I

\r?\n> believe led to development of the TIG process during WW2.

\r?\n>

\r?\n> Enough with welding history - but it makes me wonder if some of those early

\r?\n> lightweight frames Mick and Norman refer to might have been STEEL fillet welded

\r?\n> with a torch ? They would probably have been Reynolds HM (531's predecessor) or

\r?\n> Accles and Pollock (aka Accles and Bollocks)Kromo - both of which would have

\r?\n> worked with the process. I imagine that these frames were produced as a means to

\r?\n> save money on time and materials compared to a lugged frame, and steel filler

\r?\n> rod has always been cheaper than brass or bronze.

\r?\n>

\r?\n> It would be interesting to see if anyone remembers repairing or repainting any

\r?\n> of the welded/bronze welded frames in question, and if they recall what was used

\r?\n> to stick them together.

\r?\n>

\r?\n> Mike Fabian in San Francisco

\r?\n> who wonders what exactly holds those modern plastic things together ?