Brazing, soldering lugs…Turbo Torch?

[Applesauce]

Kinda stupid question time, probably… I’m kinda slowly brushing up on my frame-building knowledge after many years away from it. I don’t remember what I don’t know about it all. I’m currently stuck on: why oxy-acetylene/oxy-propane, and not just air-acetylene? Obviously the answer is temperature, but I feel like there must be some more to it than that. Controllability? Obviously the answer is that pure-oxygen flames are superior, because that’s what everyone uses. I’m just curious why?

I’m asking partly because I have an air-acetylene Turbo Torch for plumbing (copper and brass mostly, sometimes some steel), and it seems to get plenty hot. 5500° F ish? And it’s a big, brutish flame that seems to me would be great for lugs, whereby one could get a whole whack of metal up to temp at once. But I know there’s something wrong about this idea, because no one does it. (I’m smart enough to know I don’t have some kind of solution that no one else has ever thought of. ;)) But…why?

Thanks, sages.

[e-RICHIE]

Kinda stupid question time, probably… I’m kinda slowly brushing up on my frame-building knowledge after many years away from it. I don’t remember what I don’t know about it all. I’m currently stuck on: why oxy-acetylene/oxy-propane, and not just air-acetylene? Obviously the answer is temperature, but I feel like there must be some more to it than that. Controllability? Obviously the answer is that pure-oxygen flames are superior, because that’s what everyone uses. I’m just curious why?

I’m asking partly because I have an air-acetylene Turbo Torch for plumbing (copper and brass mostly, sometimes some steel), and it seems to get plenty hot. 5500° F ish? And it’s a big, brutish flame that seems to me would be great for lugs, whereby one could get a whole whack of metal up to temp at once. But I know there’s something wrong about this idea, because no one does it. (I’m smart enough to know I don’t have some kind of solution that no one else has ever thought of. ;)) But…why?

Thanks, sages.

When we started making frames at Witcomb USA we used Turbo Torches for several months. We jettisoned them because they may heat well but lack all other attributes needed to coax the filler material through and around the basic joints that make up the confluences of a typical bicycle frame.