Since sending an earlier contri to the List about Mike Mullett's achievements in building the Raleigh Dynaflyte 753 frame, I've been wondering just what purpose the silver fillet served.
The fillet run to build up a bead would be expensive in silver braze alloy, and the idea of using a cadmium- bearing rod, with the possibility of fumes for such long beads, doesn't sound too clever either. Was the fillet for additional strength or as a cosmetic feature?
I have built frames with Columbus KL and Record tubes, and others using very fine gauge Ishiwata, Excell and AMR-Camus, by running just the neat ring of silver-solder round the very finely mitred, by file of course, joints, and never had any of them break.
Peugeot used its internal brazing methods to produce hundreds of thousands of cheap to mid-range frames and I can't recall any breakages in the frames I sold. In fact I once tried to reapir the front end of one of the cheapo Peugeot tandems, built by this intern/extern brazing. The tandem had taken a massive front end head-on crash resulting in the lower head tube joint just, but only just beginning to shear. I do recall having to use a massive flame to fully undo the joint.
Anyone any views on fine-line silver-brazed/soldered joints. Good experiences or bad?
While on the theme of lugless frames joined by fillets...notice I am trying to avoid the" bronze-welded" term, I am so used to....I can confirm that the beads on Jack Taylor frames were never filed smooth. I discussed Norman's handiwork with him once over a couple of pork pies at the CTC York Rally. Having spent numerous hours filing and polishing fillets on my own frames..and I can still taste that bitter taste of bronze/brass dust that hangs around the workplace, just like having had a copper coin in the mouth.. I asked Norman about how much time he put into "filing up ". "None at all!" was his answer. When pressed to elaborate on this reply he added " I just weld them up, then I just sort of flick the tip of the flame over the beads to blend in the ripples and smooth them as much as I can. Then what is still there when the frame's been blasted, stops on and gets covered with paint"
Norris Lockley, Settle uK