Brian writes:
<< Top quality frame repairs are more difficult and require more knowledge and skill than building frames from scratch.>>
Amen! My hats off to guys with the skill levels like Brian & gang who are willing to do this. It is a extremely difficult task.
Interestingly, Brian mentions using lots of flux to ease the job, which I agree with, and yet in that Ciocc video, it doesn't look like he uses any flux at all. Maybe it's in the gas (Gasflux) but the flame color doesn't look like that. And they sort of skip from the gross job of taking that head tube apart, to a painted frame! Makes me wonder what parts were retained & used in refurbished frame...
Dale
Dale Brown Greensboro, North Carolina USA
-----Original Message----- From: brianbaylis@juno.com <brianbaylis@juno.com> To: biankita@comcast.net Cc: classicrendezvous@bikelist.org Sent: Wed, Oct 21, 2009 3:25 pm Subject: Re: [CR] Ciocc headtube rebuild
Garth,
I didn't watch the video yet, but absolutely without a doubt the remelt temp is higher than the original brazing temp. Furthermore, in order to get the tube out the old braze material must be liquidous all at the same time, which is no small chore. Care must be taken in the cooling stage of the repair because that's when the potential damage can occur to the tubes. Lugs are not effected in the same way, but care should be taken to not break them as you disassemble the frame. The old tubes are no matter; but the tubes that remain are the concern. Ideally, once the un brazing is accomplished (using lots of flux as a heat sink and to prevent oxidizing of the tubes), the new tubes should be silver brazed back together, Unlikely this was done in this case; but that's what I'm comfortable with. Bikes are repaired like this all the time and survive fine, apparently. When one uses the proper low temp silver braze material in the beginning; removing and replacing tubes can be done with virtually no negative effects to the tubes at all. That's one of the primary reasons I prefer silver brazing frames. These sorts of situations are avoided if a repair ever becomes necessary. There are LOTS of ins and outs to doing first class frames repairs. Top quality frame repairs are more difficult and require more knowledge and skill than building frames from scratch.
Brian Baylis
La Mesa, CA
In this video, it sure takes a lot of heat to get the old headtube out. Does that amount of heat exceed the amount that was needed to braze the original? The top tube was totally glowing red hot when he was done, Did the frame get damaged in the process?
http://www.youtube.com/
Garth Libre in Miami Fl USA
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