Marcus Tooze asks differences between welding methods, and what is best
for general panel replacement.
Welding, as I understand it, is fusing metal with or without a
filler of like metal. Brazing of steel is not welding, because the brazing
rod is dissimilar. I don't like brazing because the surface has to be
very clean, the flux causes trouble later with paint, and the braze metal
will interfere with any later welding. Brazing is too weak for structural
work, strong enough for sheet metal.
The differences between arc and acetylene welding are too great to cover
here; any basic welding manual will explain. Conventional arc welding is
rarely acceptable for sheet metal; if the voltage is high enough to
sustain an arc, it will burn a hole in sheet metal. Unless you are
skilled, gas welding and brazing are wonderful ways of making
nonrepresentational bent metal sculpture of previously good sheet metal.
That's my HO; of course those who can do it cannot see any problem.
My vote for the one single all round best welding method for the
semi-skilled is MIG (metal inert gas). It is a form of arc welding in
which wire is fed into the weld area, touches the puddle, arcs, melts
back, touches, etc. all while shielded from the oxidation of the
atmosphere by a cloud of inert gas (generally a CO2-argon mixture). If
the parts are clean and in contact with each other, you can be making good
welds with an hour or so of practice. Heat is highly concentrated,
limiting distortion. One can weld FAST (gas welding sheet metal is an
exercise for only the very patient). Biggest drawback is that welds often
stand proud of the surface, requiring lots of grinding if you want things
flush. The weld bead is hard, so grinding isn't easy. My 110 v Lincoln
welder and gas setup cost about $700 and easily paid for itself on one
car. I have no experience with the lower price units one sees advertised.
Be advised that 110 v units rarely will weld steel thicker than 1/8 inch.
Ray Gibbons
British Sports cars are ideal subjects for amateur restorations... they
appear to have been designed and built by amateurs originally.
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