Re: [CR]Walter Serena= Serena bikes?

(Example: Production Builders:Cinelli)

Date: Fri, 25 Feb 2005 17:04:09 -0500
Subject: Re: [CR]Walter Serena= Serena bikes?
From: "Doug Fattic" <fatticbicycles@qtm.net>
To: <classicrendezvous@bikelist.org>


Ronald Manseau asks this question: Now could someone here describe the forging method that apparently Piero Serena was using into the building of the frames?

Perhaps this method of putting tubes together could be described as "brass brazing tubes together using the forge method". My English English is getting a little rusty but when I was first learning to build frames at Ellis-Briggs in Shipley we called it hearth brazing (the Brits can correct my memory). Now most use an oxyacetylene torch for applying the heat to the tubes. What we did back then was hang the frame above some bricks and the part to be brazed was surrounded by fire bricks as well. The torch was like a natural gas fire thrower and oxygen was added to intensify the flame. This thing was one big mama compared to our itsy-bitsy torches used now. Anyway the torch was pointed at the frame like a fireman's hose and you would watch while the frame got to the right color (cherry red). The bricks behind it balance the heat front and back. Next, brass would be applied in the general vicinity of the joint and capillary action would take over and suck it all inside. Of course plenty of flux would assist in completing this job. I remember being amazed the first time I watched Andrew (Jack Briggs apprentice) braze a joint using this method because I wondered how the brass actually got where it was supposed to go. I learned to watch for the gold color of the brass coming all the way through the bottom bracket. I built my first frame this way on the four main joints but used oxyacetylene everywhere else. Andrew sensibly gave up this practice that summer I was there (1975) and started building the whole frame with an oxyacetylene torch. This method is why British builders pinned there frames before brazing because a spot braze would melt and the position of the tubes to each other lost when the entire joint would get red.

Now we silver braze tubes together and the tubes don't get red or even any color at all. Much superior but maybe not as much fun as that giant flame thrower.

Doug Fattic
Niles, Michigan