I admit I watched the video to hear Pelizolli say his nickname, "Ciocc". I felt vindicated (I had the correct pronunciation down) - and also closer to my frame's legendary builder.
I didn't realize that in 1973 Ciocc used such beautifully cut, ornate lugs. When did he switch to the simplier (but no less beautifully executed) lugs such as those used on my early 80s Mod San Cristobal?
Steve Whitting
"The Ciocc Cat"
Prairieville, Louisiana USA
Website at http://ciocc-cat.angelfire.com/
From: Norris Lockley <nlockley73@googlemail.com> Subject: [CR] CIOCC Headtube repair To: classicrendezvous@bikelist.org Date: Wednesday, October 21, 2009, 6:10 PM
I have to agree with Dale and Brian on this one....replacing tubes is a very skilled business, and I have to admit that such jobs are not ones that I look forward to...at all..but sometimes with a rare or treasured frame there's no alternative. It is certainly far easier to braze the tubes together than to unbraze them!
Obviously Pelizolli is extremely adept with his acetylene fuelled torch which throws out a great deal lot of heat very locally but does not produce a big enough enveloping flame to cover the whole of the lug at the same time...hence an even bigger nozzle is needed...and that creates even more heat. .. and increases the possibility of burning the tubes, particularly as he does not use any form of heat barrier.
Way back in the day...that is in the rearly 50s, before the now ubiquitous oxy--acetylene rigs took over welding and brazing pocesses, we used to use town gas and compressed air torches.
These had just one large venturi through which the gases emerged and were burned. Two largish thumb levers controlled the flow of the gases from tiny flames through to great big ones.but they were never as hot as or as ferocous as acetylene fuelled flames. For brazing frames you used to create a large brush flame..plenty of gas and plenty of air to increase the heat...that would completely envelope any lugged joint even a bottom bracket. The heating up process took longer...but there was never any chance of actually burning a tube Because the flame was big enough in volume and hot enough to heat the whole of the joint up at the same time, the tubes used to slide out more easily. I think that Ellis-Briggs still use such a torch for repairs.
As for fluxing the tubes neighbouring the joint, that's fine idea, but there are proprietary heat shields, normally a type of heat-resistant mouldable mastic, that do the job better.
But in any case replacing a head tube is one of the easier tubing repairs like replacing a seat-tube. For the repair shown on the video, there was no need whatsoever to put a torch on the frame to remove the old head tube. The best way, but possibly not the quickest way..let's say the safest way, would have been to have cut away the headtube as near to the lugs as possible and then to have reamed away the remaining tube with a floating adjustable reamer...easy does it! Without a reamer, the metal could have been filed away or even..forgive me for harking back to one of last week's discussions..removed with a Dremel tool.
When replacing a seat tube, or a steering column I never use a torch...just a hacksaw and either reamers or files...or both
The other way, to minimise heat but not to get rid of it all together would have been to cut the head tube away as near as possible to the lugs and then , with a much smaller nozzle to have removed the remaining small amounts of metal within the lug's interior. Pelizolli even when he had taken the head tube off in two sections would still have had to remove the remains of the head-tube from the lugs...presumably using heat.
Sometimes the old ways are still the best ways.
Norris Lockley
Settle UK...never knowingly influenced by progress.