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Old 01-27-12 | 01:36 AM
  #13  
Dovetube
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Joined: Feb 2011
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Eisentraut expressed some disaffection resonant with me. Not every bit helps

I wasn't listening but things went well and the video was made by someone who knows stuff I don't. He didn't seem to heat the inside surface of the headtube to help things along. (although acetylene will tend to pull some trick like accumulating inside a tube; find someone to translate the kanji from your torch instruction manual.) If you got a B-size tubeset and you're making a ~52cm frame you can have a bunch (~1.5cm) of extraneous headtube sticking out of the lugs to heat in hope of promoting sufficient temp throughout somewhat evenly. A difference with copper pipe plumbing is not worrying about burning a hole through the precious tube but there were probably admonitions to keep the flame moving. Silver is not too frustrating to work with if everything is clean and the lugs aren't stamped, but needs really tiny gaps at the dropouts and stays, bridge, etc. (You aren't supposed to do old dropouts with it, unless you can crimp like Basso (supposed to sound like bend...Beckham.)) I find silver flux frustratingly akin to really stale frosting and you should really pay attention to the part of the video where he says the lugs have been filed and fit well. Whatever part of the tube the lug scrapes flux off may be an area which sticks less. Brass is challenging IMHO and I failed at it with solidox pellet torch which is probably still menacing some locales. I think I've done it right once, with silver in the BB. It sparkled like kid-friendly fireworks, [snake, sparlker];(at the head tube lugs the BB is really good for silver because it's so massive with heat retention and the MAPP gas flames that one holds by the cartridge can do those on a hot day. Mostly investment-cast BBs are what are available but they used to also be "rolled" which was better done with brass, and is also found on old store-bought frames hint. Friends of mine have procured Bridgeports for mitering the tubes. (It's weird I can't remember the term for the most important thing to do, I'm replaying the utube (hopefully)with sound.) OK mitering the tubes is what everyone says maximizes the strength. If you're doing something stupid like drawing the more parallel parts of the main triangle together with buffered twisted wire loops good mitering will leave the lugs loose over their tubes, I've heard. The same friend appallingly initially mitered his tubes with carpentry hole cutters, and fondly displayed a photo from some text showing one of the masters' joining setups using a rock to prop the tube. (Maybe you've seen the book saying the French toss the whole bike into an oven; An oven is kind of a good idea for paint I thought, but I wasn't close enough to any pizza entrepreneurs.) I think the Paterek guy says to make a plywood jig with medium holes where the joints are. Always have a full bucket of water near site of your brazing, and serious charged extinguishers as well. At this point I would ask at least those who are conventionally proportioned why they want to do this so much. To get only one solid color without any masking costs $300 not including S+H, and you do not have the attention span to finish your work in sufficient preparation for chroming. (Well, I guess the platers can lay on thick copper, but there you go, defeating significant original criteria.) Really nicely done bikes like Treks and Austro Daimlers and Atalas go for cheap. I had tiny bits of steel embedded in my eyeglass lenses from doing my mitering with Dremel cutoff wheels, although I was able to do one frame out of an inappropriate housing situation using construction site power; that was when ambient weather I think helped. Don't keep your unsealed MAPP cartridges indoors if you don't want to get evicted. I didn't have the nice quick-change bits either, (attempting a Raleigh Pro-style seatstay attachment will give you insights into Calculus.) It didn't hold when I hit some Volvo guy pulling up across my narrow lane, probably fillet silver headtube joins, which doesn't work. I made him buy me a new MAPP cylinder. I heard apprentices filed lugwork for a couple years before they did joints, and then would be instructed to saw them apart to reveal cross-sections, to check flow (of brass, Ag is safer.) Somewhere there's some smelter who'll dip that practice assembly to recover the silver. Also be prepared to cuss because once you start you have to finish and the chemistry incurs a deadline and only experience or maybe checklists will find you fully prepared and not having to later align the thing. Did anybody see the Paramount P-15 that went for ~$175? I'll also say a fully pitted Treviso has the same psychological worth as a cool homemade with crappy paint. Except nobody really knows what assemblage of tubes the Treviso has. Oh did I mention what anatomical grip the bike shop you know or don't know will have when you have to mill and face your article? What you have to do is copy a bike you already like; I recommend Ciocc for tall people, and most of their smoke chrome flakes off rendering the piece not worth much. MAX bikes seem to crack at the seat clamp, (acknowledged non-sequitur.) Contrary to any appearance of erudition, I've only got one fork (and a half) to claim; these days the weight savings obviate carbon. BTW send me all your unwanted 12mm, aero, and double-taper seatstays and congratulations or sympathy for perusing this. Frankly, I'm going to build a recumbent to use them before I finish any more forks.
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