[Classicrendezvous] Hearth brazing.. Was; Colnago quality


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From: OROBOYZ@aol.com
Date: Tue, 17 Oct 2000 09:55:01 EDT
To: Classicrendezvous@bikelist.org
Subject: [Classicrendezvous] Hearth brazing.. Was; Colnago quality

In a message dated 10/17/00 4:24:23 AM Eastern Daylight Time, Hilary.Stone@Tesco.net writes:

<< Mercian still hearth braze all their frames. And Barrie Whitcomb also makes the few frames he still makes that way too. But Bob Jackson uses conventional oxy-acetylene torches without hearths hough I don't think that's necessarily any better ­ it depends on the skill of the builders. >>

I want to rush in here and make sure every one knows I was not against hearth brazing in terms of creating a useable, reliable bike. True, it seems a more crude and volatile method, plunging the whole joint into a large flame and "cooking" the tubes and lugs at once, but the long years of practice has demonstrated that long lasting bicycle frames can result from this old method. The hand held torch is what we expect to see nowadays (Oops! I guess a tig welder is really what we expect to see!)

But the point is, jillions of steadfast and sound bikes have been made using "too hot" hearth cooked brass brazing techniques. While I prefer to use silver (brass at dropouts) I simply do not go for that rap about "brass overheating joints and leading to premature failure" that many outfits blab on about why you should buy their silver "soldered" frames. Of course, if we come back to 0.5 or 0.4 MM tubing, one better not warm up the hearth!

Dale Brown