Hi again,
OK, since my MG-TC is being repainted and will be done
in time for spring I've got to get started working on my MGA.
I've owned the MGA for almost 10 years and it's starting to look
pretty bad. It didn't look too good when I got it but it wasn't
bad enough not to drive. But since I got the TC the MGA has been
outside. Even summers in New England are brutal on old cars, even
when they are covered.
Anyways, I know it needs new rocker panels, sills/pillars,
etc. I assume that I'll also want to take the body off and repair
the floor supports, battery boxes, etc. I know not to take the
body off until I get the sill strong enough but what is a good
approach? What is the best way to replace the sills? I assume you
pull the wings off (Heh, heh, heh) first, then just cut the rusted
section out.
Has anyone got any experience re-doing an MGA? How about
using the small rust repair pieces vs. the entire pillar assy.? Advice
in general?
Just got a MIG welder (110v Lincoln) to play with. I've
done some old fashion stick welding before but not for a few years.
Within a few minutes I was running some not too bad beads on some
20 gauge. Trying to get a good butt weld, well....more practice.
Dave
From rwg1@cornell.edu Tue Sep 11 11:58:30 2001
From: (Roger Garnett) rwg1@cornell.edu
To: (British Cars) british-cars@autox.team.net
Date: Wed, 24 Nov 1993 09:31:56
Subject: Re: Welding
I started this last week when this thread started- looks like it's still
appropriate.
========================================================================
Introduction to Welding, Types & Equipment
Welding is a craft that can be performed reasonably by amateurs. As
always, good equipment is important for producing good work. The basics
and theory can be learned solo, and from books, but like many crafts,
learning from someone proficient is very desirable. A real good way to
start is to take some kind of night-school or similar beginning welding
class. You get exposed to various equipment and methods. There are often
advanced classes available, as well.
Among the first things a new welder needs to understand, is what the
different kinds of welding processes and equipment are, and their
application. A quick rundown:
Soldering: Bonding by melting a soft metal to the surface of pieces to be
joined. Low temperature. Good for joining dis-similar materials.
Brazing: Similar to soldering, but uses a higher temperature to fuse the
filler metal to the work pieces. Stronger bond. (Includes "Silver
Soldering") Work heated to pre-melt temperatures.
Welding: Joining 2 similar work pieces by melting them together, usually
with an additional filler rod of some sort to take up space.
Materials must be similar.
Cutting: Work is heated to melting point and beyond, and "cut" by
oxidizing metal. (Literally burning it away).
Shield: A barrier to keep oxygen away from heated work to prevent
oxidation. Includes chemical coatings called flux (liquids, pastes,
solids, which may be vaporized into a barrier gas when heated), and inert
gasses.
Gas Welding
Uses Flame from burning gas to create welding heat.
-Propane torch- Soldering, heating Good for sweating pipes, starting
fires, and spending hours trying to heat frozen bolts, while the
surrounding metal gets just as hot.
-oxyacetylene torch: Cutting, welding, brazing, soldering, leading.
Most universal and useful welding tool. (Uses Acetylene gas and Oxygen
for hot flame.) With the right bits, rod, and technique, you can weld
almost anything. Good for cutting anything from sheet metal to the
turret off a tank, lead filling, brazing (a sort of hard soldering
process) welding plate, welding sheet metal, welding aluminium,
heating frozen bolts, or alternately cutting them off, drilling holes in
plate, welding cast iron, shrinking and forming steel, and can double as
a flame thrower in a pinch. Drawbacks are: Overheating of some types of
work, harder to control quality of some processes.
-Oxy-propane: Soldering, brazing, heating.
A cheap compromise between low cost and portable propane, and
Oxy-Acetylene. Better than the former, not as good as the latter.
Arc welding
Uses an electric arc to create welding heat.
-Basic AC & DC arc welders (AC is cheaper) , and steel rods of various
types for different jobs. Makes some of the best welds on heavy gauge
steels and cast iron. Cutting rods can make clean holes through thick
stock, and are about the only thing which can cut Kryptonite bike locks.
Very difficult to weld thin metals. You can also get a carbon arc torch
to use an arc welder to braze. Eastwood's "stitch" welder is a gimmick
used on an arc welder to buzz the rod in and out, which may help on
thinner stock. (learning how to weld better, or going to a different
process is a better idea.)
-MIG (Metal Inert Gas): A DC arc welding process which uses filler
metal fed in the form of a spool of thin wire, shielded by flow
of inert gas (CO2, Argon) instead of flux used in Arc. Very fast,
with less heat buildup. Very good for sheet metal, due to minimal
heat distortion. Harder to weld thick stock, as welds are weaker
due to poorer penetration. The modern choice for steel body work.
-TIG (Tungsten Inert Gas) : A high frequency AC arc process which uses
a tungsten electrode shielded by an inert gas to create a fine,
controllable torch. Uses a separate filler rod, as in Oxy-Acetylene
welding. Capable of welding very thin metals. About the best
process for Aluminium, Stainless steel, and other exotic stuff.
Resistance welding: includes spot welding. Uses the heat generated
by electricity flowing through work to melt and fuse. i.e.- put an
electrode on either side of 2 overlapped sheets of steel, turn
on power. Metal in between heats up, and melts together.
An old favorite for assembling car bodies.
Plasma Cutters:
Not a welder, but related. A high voltage arc is used to superheat
and ionize a stream of air to the "plasma" state. The stream of
plasma makes a rapid, clean, narrow cut with minimal heating of the
work piece.
There is, of course, a wide range of equipment, capabilities,
quality, and pricing. The quality can make a big difference in
the ease of use and quality of work. "You get what you pay for."
Experience, and practice, practice, practice are very important.
Learning from an expert gets you there a lot faster.
________________________________________________________
Roger Garnett (Roger_Garnett@cornell.edu)
"The South Lansing Centre For Wayward Sports Cars"
"All donations of stray, orphaned, odd, neglected, etc.
sports cars and bits in need of a good home accepted."
"The drop off bin is right there- behind the barn..."
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