Originally Posted by
unterhausen
that is a weird sequence. I have always thought the traditional DT/HT; ST/BB; TT/HT; DT/BB; TT/ST sequence made the most sense if you aren't using a jig. I think the reason he tacks the DT/HT first is because that joint most often requires the most blacksmithing.
Re the sequence -
The three lugs are already finished brazed. Then, the bb shell is added onto the mitered ends of the down and seat tubes. Then, that joint is brazed last. Kalavinka's fixtures are sophisticated and well thought out. His procedures (and those like his...) allow for a minimum of stress to be put on, or added to, the main triangle before and during the heat cycles.