Monday, 25 February 2013

Lugged bike frame build

I've just taken the first step on the bike build project. Having done the preparatory work such as reading everything I can lay my hands on, setting up the workshop and buying the necessary basic tools; this weekend I did my first practise brazing. You can see the results below - not cosmetically pretty but full joint penetration which I was pleased with. Now this is brazing with brass, so significantly more difficult than silver based brazing because:
  • A much hotter flame of (850-900 C) is needed (650-700 C for silver) but I managed to achieve this with an air/propane torch, so there us less chance of overheating the steel tubing.
  • The flux is a bitch to get off afterwards.
  • Brass doesn't flow as well as silver.
A little more practise is needed to tidy up the shoreline and make sure that I'm not overheating, but brass is cheap so many trials are possible and when I am competent enough silver brazing it will be simple by comparison (hopefully).