Thanks for the explanation it painted a good picture. A lot like sweating a joint.
"This method is why British builders pinned there frames before brazing because a spot braze would melt and the position of the tubes to each other lost when the entire joint would get red."
Would this also explain why some bike frames have been tacked with what appears to be copper prior to brazing or was that done for some other reason entirely?
Marcus Coles
London, Ontario, Canada