Old 07-13-18, 05:41 PM
  #9  
Doug Fattic 
framebuilder
 
Join Date: Dec 2009
Location: Niles, Michigan
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There are several huge advantages to splicing in a new piece of top tube rather than trying to replace the whole tube. 1st there is no heating involved in removing the damaged tube. And it is much easier to clean and prep for brazing. It does take a bit of care to get the ends square and some thought and investigation where the butting starts and ends. 2nd there is no mitering necessary although the 4 ends have to be cut to an exact length and be 90 square. 3rd getting out an old tube without damaging the lugs (especially if it has been pinned and brass brazed) and getting rid of any left over brazing material can be a real effort and not always successful. Cleaning up the end of a cut off tube is way easier by comparison.

Of course one has to have a lathe and thicker walled tubing to be the splices that can then be shaved down to within a thousandth of an inch to exactly fit each of the four sockets. I brazed one splice to the new middle of the top tube and the other splice to one of the ends of the frame tube. There is enough spring in the frame to allow the new tube to fit into the frame. Since I’ve been making frames professionally longer than many posters have been alive it was not a difficult braze for me to finish the other ends of the splices. Someone not as sure of how much silver should be added or have as great heat control could preplace a ring of silver inside instead and sweat it out.

I suppose it took me somewhere between 2 and 4 hours to complete the entire task not including painting. I made my frame out of 7/4/7 heat treated tubing so something heavier would be easier to do. After primer it looks indistinguishable from an undamaged frame.

Over many years I’ve repaired (including alignment) and repainted hundreds of frames (or more I haven’t counted). The Japanese made frames were some of the very best. Unlike some of the classic European builders (many who I have personally visited back in the 70’s) that were a bit sloppy and crude in their methods, the Japanese knew how to make an aligned steel frame.
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