I've got my torch. I bought brass and flux. (I've only really used silver before, so brass will be a first.) A C&V forumite gave me some tubing scraps. Time to melt some metal. One of the scraps is the end of a downtube that had been melted out of a lug. There are some low spots which the sandpaper won't reach. (I haven't any sandblasting capability.) It definitely seems like it had been deformed a bit in a crash. For my needs though, it's helpful that it was already mitered. Still, even after a bit of filing it doesn't fit terribly well on its tube mate, pretty good at the bottoms, not so well at the edge. I would certainly try to do a better job cutting the miter in the first place if I was building a frame, especially a fillet brazed frame, but would this fit be good enough for a beginner's fillet brazing practice, or is all my brass going to flow into the gaps?



That black spot is a low spot in the metal from the crash I presume the frame endured. You can also see a remnant of the brass from the original build.