Be assured that I do not intend to put down the bicycle industry in any way at all. I just would like to make sure that the bicycle I build will not produce noxious waste that the earth could never break down. Are there any such cases with welding metals together? I realize that bicycles are probably about 3000 times more green than autos (which makes me proud to be a biker), but I do see the possibility for irresponsibility because of that fact. I don't think that the "we're already greener than cars, so we have a little leeway" viewpoint is too green. While I know that we will probably never be able to achieve an earth that is as clean as we would like it, I want to do as little damage as possible. I'm not trying to rag on you framebuilders. I just wanted some information about the welding process and about its waste products if any. I know next to nothing about welding and metals in general except for the fact that they compose my lovely little bike .