There are a few problems with using coat hanger as filler rod. First, you don't really know what its composition is, though it is typically mild steel. Second, you don't know what the plating on it is. Third, it might be too large a diameter. The rule of thumb is that the filler rod diameter should not be greater than the thickness of the material being welded.
With that said, I have no compunction with grabbing a coat hanger to weld up the neighborhood kid's broken BMX frame. The little snot.
Steve Barner, Bolton, Vermont
> Date: Mon, 12 Jul 2004 12:33:48 -0700 (PDT)
\r?\n> From: Fred Rafael Rednor <fred_rednor@yahoo.com>
\r?\n> To: Classicrendezvous@bikelist.org
\r?\n> Subject: [CR]Re: Aircraft Welding on Rene Herse Frames?
\r?\n>
\r?\n> That doesn't really explain the large number of aircraft,
\r?\n> racing cars and motorcycles whose superstructures were made of
\r?\n> chrome-moly tubing and assembled by oxy-acetylene welding.
\r?\n>
\r?\n> Perhaps the critical difference is actually the wall thickness
\r?\n> of the tubing. There might also be a question of which filler
\r?\n> rod to use. When I was doing this sort of work, we were told
\r?\n> that metal coat hangers were actually the best filler rods for
\r?\n> use with chrome-moly tubing. Perhaps that also only works well
\r?\n> with greater wall thickness.
\r?\n> Cheers,
\r?\n> Fred Rednor - Arlington, Virginia
\r?\n>
\r?\n> --- hersefan@comcast.net wrote:
\r?\n> > Well sort of.....
\r?\n> > Some old frames such as Rene Herse and Alex Singer had
\r?\n> > handmade lugs which were made by (I'm pretty sure anyway) gas
\r?\n> > welding. Tubing was cut, mitered, gas welded together, then
\r?\n> > reamed out and cut, and voila - a lug or bb shell. This was
\r?\n> > often done when custom angles or sizes were needed.
\r?\n> > The reason that such welding works on these parts but would
\r?\n> > be a dissaster on a lightweight frame is that the material is
\r?\n> > different. For welding, a mild steel is used. Steels with
\r?\n> > higher carbon content become brittle (actually when cooled,
\r?\n> > the damage of overheating really occurs on the cooling side
\r?\n> > of things).
\r?\n> > Mike Kone in Boulder Colorado
\r?\n> > -------------- Original message --------------
\r?\n> >
\r?\n> > > David Benson brings up an important point to consider - in
\r?\n> > the thirties it was a
\r?\n> > > standard process to flame weld the various types of tubing
\r?\n> > that were used in
\r?\n> > > aircraft construction. A filler rod was employed and the
\r?\n> > results could be very
\r?\n> > > nice indeed - depending on the skill of the welder, of
\r?\n> > course. I discovered this
\r?\n> > > in an old book on aircraft welding from @ the late 1930's,
\r?\n> > or maybe it was the
\r?\n> > > WW2 era. If I recall correctly, the gas of choice was a
\r?\n> > Hydrogen/Oxygen mix at
\r?\n> > > low pressures. Like many welding processes it was not easy
\r?\n> > to master, and the
\r?\n> > > problems with getting a reliable joint to survive aviation
\r?\n> > service is what I
\r?\n> > > believe led to development of the TIG process during WW2.
\r?\n> > >
\r?\n> > > Enough with welding history - but it makes me wonder if
\r?\n> > some of those early
\r?\n> > > lightweight frames Mick and Norman refer to might have been
\r?\n> > STEEL fillet welded
\r?\n> > > with a torch ? They would probably have been Reynolds HM
\r?\n> > (531's predecessor) or
\r?\n> > > Accles and Pollock (aka Accles and Bollocks)Kromo - both of
\r?\n> > which would have
\r?\n> > > worked with the process. I imagine that these frames were
\r?\n> > produced as a means to
\r?\n> > > save money on time and materials compared to a lugged
\r?\n> > frame, and steel filler
\r?\n> > > rod has always been cheaper than brass or bronze.
\r?\n> > >
\r?\n> > > It would be interesting to see if anyone remembers
\r?\n> > repairing or repainting any
\r?\n> > > of the welded/bronze welded frames in question, and if they
\r?\n> > recall what was used
\r?\n> > > to stick them together.
\r?\n> > >
\r?\n> > > Mike Fabian in San Francisco
\r?\n> > > who wonders what exactly holds those modern plastic things
\r?\n> > together ?