Details: I'm pretty sure I got it too hot for too long. I did start on the BB shell, and only after it was hot did I move on to the tube. Initially, the silver flowed well, and penetrated through most of the joint. However, toward the end it didn't seem to want to go through in one particular spot, and the flux on the tube took on a black appearance. I took this to be burnt.

Part 2: I took the advice to soak it, add flux and try again, and it seems to have worked. I focused my heat more, and tried to work more quickly. The silver flowed into the gap left behind the first time, and appears to have come through the inside of the bb shell. Unless I took the temper out of the tube, i think it will be solid.

Hindsight: I did buy some cheaper, practice lugs, but in my enthusiasm to get into this, I jumped right in with the better stuff. Ah well, live and learn. I think I'll stop now, put the frame aside and do some practice joints with the cheaper parts for a while. I'll finish the frame off later, hope it holds up for a little while, and chalk this one up to experience. I probably won't invest a lot in paint!

Oh, and thank for the advice unterhausen. I like your suggestion. I could probably put together a few little jigs and things, and get a better handle on brazing at the same time!

Cheers,
Neil