My frame snapped and I want to fix it by welding it back together. In order to do that, I need to know what all is in the aluminum.
You can NOT weld back an aluminum frame unless you have the facilities to anneal and heat treat the frame again. Rewelding without the post treatments will result in a very soft area around the new weld causing sudden catastrophic failure... this means if you are riding it could fail at any time causing injury or death. EDIT: Wait just a durn minute. The 2100 and 2300 had carbon fiber tubes bonded to aluminum lugs and stays. If your bike failed then you ABSOLUTELY should not try to weld it. The heat from welding (even if you had post treatment facilities) would destroy the bond between the CF and aluminum. Fair warning- cut the frame apart and throw it away.
