Subject: TIG welder advice

From: [email-masked] (Gavin Donahue)
Date: Fri, 13 Dec 1996 01:21:25 -0700

I plan to buy a TIG welder to weld light CrMo tube (bicycle tubing). Does
anyone have experience with this process and have an opinion about
specific machines that would help guide my purchase. I have gas welded
thin steel but never used a TIG torch. Any insights into this process will
be helpful. I did read the FAQ but I'm curious about first hand experience
with specific machines. Is the specific torch style a major factor in
being able to get at mitered joints?
I'm also interested in fillet brazing of this material. Any bicycle
builders out there that would be able to tell me the relative merits of
the two techniques?

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From: [email-masked] (Reckless)
Date: Sun, 15 Dec 1996 08:11:21 GMT

>builders out there that would be able to tell me the relative merits of

If you're good with gas welding you'll do just fine with TIG, probably
even better.  Certainly was my experience, I get beautiful, strong
welds with the TIG, but many of my oxy-acetylene welds were only
strong, not very pretty.  

The torch style doesn't seem much of a factor in getting to tight
spots/mitered joints, but you'll probably need a gas lense so you can
extend the tungsten to get into the deeper corners.  Doing mitered
joints (at least for me) is much easier with the TIG than with gas
welding.  The only real trick to TIG welding is clean, clean, clean
the metals to be joined.  Dirty metal won't weld well at all.  If
you're going to be using the welder on a production basis consider a
water-cooled torch, otherwise the air-cooled should be just fine.

As far as brazing goes (on bicycles) I know that it is common for
attaching brake mounting studs, but I don't know if the frame is
normally assembled that way.

See Garfields post in the "Miller Tig welders" thread, he has very
good info on selection of the welder (IMO).

-Reckless
Happy owner of a Lincoln Square-Wave 175.  The foot-pedal power
control is very cool to use.