In article .com,
says...
Hi. I am wanting to get into welding, and I have a question for those
who may know. What kind of welder would be used to make a vent like
this http://oldworlddistributors.com/pix_...ryer_vent.html.

If I were doing that, if I wanted a good color match on the joints
I'd probably use self-fluxing copper brazing rod and a small
acetylene torch for good heat control. If the color match on the
joints wasn't important, plain old 60/40 solder and acid flux.

If you're doing thin copper with an oxy-acetylene torch you need to
be careful not to overheat it, but it's a lot faster than doing it
with an electric iron.

--
is Joshua Putnam
http://www.phred.org/~josh/
Braze your own bicycle frames. See
http://www.phred.org/~josh/build/build.html