TIG won't harm any metal you are likely to come across in bike building (that said I don't know the specific metal you are dealing with here). There was a whole BS as much as possible campaign to stop the barbarians which left the industry to develop a path for rehabilitation after they were stuck with the fact that steel forward would be mostly welded. TIG may add enough heat to cause problems for adjascent brazed joints. of course they could be rebrazed. TIG is also ideal for taking a very slow stitch approach that won't build a lot of heat. It will take a lot of heat, to get the braze out.
Oxy somethingorother is a good bet. I use OP, and some others do also. OA is far and away the most comon but is dirtier, hotter (not much advantage here where welding and cutitng is not the use), and kinda a dangerous choice for the home shop. That said, if you already have the OA you aren't really adding anything new to the mix by using it, and that is what most use. The smith aa1a torch is the sort of thing. I use a Meco aircraft torch more like a TIG torch, but I like to weld with it also.
"with lots of noise."
You don't want the noisy setting you want the quiet more liquid one. If it is really noisy that usually means too much oxygen and you will burn carbon out of the steel.
Last edited by NoReg; 11-07-08 at 08:25 PM.