The Haynes Welding Manual - VolksPage.Net

2.19 If you're lucky, the welding store near you will
have a demonstration area, such as here at Altair
Gasses & Equipment, Oxnard, California. Here a
portable MIG unit is being tested where customers
can watch through a large safety lens (behind
operator, at right). You can get a feel for different
equipment before you decide what machine best
suits your needs.
necessary. These smaller wire-feed machines usually have
4-7 heat range settings from 30 to 110 or 140 amps, and
can handle light sheet metal such as auto body material up
to metals as thick as 1/4-inch or 3/8-inch (less maximum
thickness is possible on aluminum). They either have
wheels on the bottom or have optional, wheeled carts that
make then very easy to move around your shop or garage.
Many beginning weldors like to build their own welding cart
as their first project with a new welding machine.
The shielding gas used with MIG machines can be CO2,
Argon, or a mixture of the two, depending on the materials
you are welding. The basic gas used most often is straight
CO2, because it is the least expensive. Various sized gas
bottles are available from small, very portable 20-cubic-foot
bottles (about two feet high), to 120-cubic-foot bottles (four
foot high, six-inches in diameter) that can supply enough
gas for eight hours of continuous welding. The small bottles are fine for occasional
home/shop use where long seams are not welded regularly.
One of the factors that has made MIG welders so popular with home/shop
users is the relatively easy learning curve associated with using them. Given a little
instruction and practice, most people can be up and welding a decent bead in
an hour or two. We're not suggesting that that person would then be ready for a
full-time job as a weldor, or that his/her first welds would pass rigid specifications
for nuclear reactors, but the wire-feed machines are easier to learn than most
other systems. One of the factors that makes it easier is of course not having to
deal with feeding the filler rod in with your other hand. In automotive body work
this can be particularly helpful when you have to hold something with your left
hand, like the alignment of two pieces of sheet metal, while you tack them together
with the one-hand MIG torch. Torch position is very important in all forms
of welding, and the fact that the distance of the MIG tip from the work is constant
(in many cases the nozzle is actually touching the work to steady it) makes controlling
the weld much easier.
After selecting the proper heat setting based on the thickness of the material
Types of welding
2.20 If you are interested in cars as a hobby, whether it be kit cars,
street rods, race cars, or antique restorations, you should become
familiar with various welding techniques, and perhaps buy a system.
When fabricating parts at home, it's a lot easier if you have your own
welder, even if all you do is tack parts together and bring them to
someone else for final welding.
2.21 Typical home/shop projects
such as a utility trailer, race-car
trailer, metals rack, shop cart, engine
stand, hoist and much more can be
built at home with either MIG (shown)
or an AC arc welder.
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