To add from the 86 Bicycle Guide article, Alberto says that the headtube joints for the top and downtubes are brazed as a standard lug, but that the other joints are first carefully fit checked, then "I insert this ring of silver inside the tube before I slip it over the lug, then I heat the tube, the ring will melt and the silver will flow into the joint. I braze at a lower temperature to maintain strength of the joint--500 degrees centigrade rather than 700 for a normal frame." Lou Deeter, Orlando FL