Schumacher 00-99-000985/1009 - Manuel (Page 16)

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Low vs High Voltage Welding Electrodes
Make certain you have the best electrode for the welding job you intend
to do. electrode manufacturers make most of the standard welding
electrodes in two basic types. One type has been designed to run on
welders with high Open circuit Voltage. The other type electrode is
designed to run on welders with low Open circuit Voltage. Most of your
welding will probably be done with low open circuit voltage ac rods such
as E-6013 or E-7014 general purpose rods. Use rods of 1/16, 5/64, or
3/32 inch diameter (the thicker the rod, the more experience you need.)
High open circuit voltage rods such as 6011, 7018, etc. will not work with
most low power welders (100 amps and smaller).
electrode manufacturers have adopted a uniform marking code for
welding electrodes. Each electrode is marked with a prefix letter and four
numbers. Each of the numbers has a particular significance. For example:
a commonly used general purpose electrode is marked e-6013. The e
signifies the electrode is for electric arc applications.
The first two digits in the number indicate the minimum tensile strength,
of the deposited metal, in thousands of pounds per square inch. In this
instance, 60 indicates the melting rod will have a minimum tensile strength
of 60,000 p.s.i. The third number indicates the welding position for which
the rod is intended. a number 1 indicates for use in any position. number
2 represents an electrode restricted to welding in horizontal and flat
positions. Number 3 represents an electrode intended for use in the flat
position only. The fourth digit shows some special characteristics of the
electrode such as weld quality, type of current, or amount of penetration.
For all practical purposes, fourth position marking will not affect the rod
you would normally purchase.
Striking The Arc
4.4
To strike an arc, bring the tip of the rod in contact with the work surface
and then quickly raise it until there is about 1/8 inch (3.2 mm) gap between
the rod and the work, as can be seen below.
The easiest way to strike an arc is to scratch the tip of the rod (for a
short distance) on the work surface (as you would strike a match), then
quickly lift it the required 1/8 inch (3.2 mm). It is important that the gap
be maintained during the welding process and that it be neither too wide
or too narrow. If the gap becomes too narrow, the electrode will freeze or
stick to the work piece.