Weldclass FORCE 160MST MK2 Operating Instructions Manual page 18

brittleness, generally cracks when attempts are
made to weld it. Trouble may also be experienced
when welding white-heart malleable, due to the
porosity caused by gas held in this type of iron.
Copper and Alloys
The most important factor is the high rate of heat
conductivity of copper, making pre-heating of
heavy sections necessary to give proper fusion of
weld and base metal.
Types of Electrodes
Arc Welding electrodes are classified into a number
of groups depending on their applications.
There are a great number of electrodes used for
specialised industrial purposes which are not
of particular interest for everyday general work.
These include some low hydrogen types for high
tensile steel, cellulose types for welding large
diameter pipes, etc. The range of electrodes dealt
with in this publication will cover the vast majority
of applications likely to be encountered; are all
easy to use.
MILD STEEL :
E6011 - This electrode is used for all-position welding or
for welding on rusty, dirty, less-than- new metal. It has
repair or maintenance work.
E6013 - This all-position electrode is used for welding
clean, new sheet metal. Its soft arc has minimal spatter,
moderate penetration and an easy-to-clean slag.
E7014 - All positional, ease t o use electrode f or u se on
thicker steel than E6013. Especially suitable for sheet metal
E7018 - A low-hydrogen, all-position electrode used when
quality is an issue or for hard-to-weld metals. It has the ca-
pability of producing more uniform weld metal, which has
better impact properties at low temperatures.
CAST IRON:
ENI-CL - Suitable for joining all cast irons except white
cast iron.
STAINLESS STEEL:
E318L-16 - High corrosion resistances. Ideal for dairy
work etc.
Joint Preparations
In many cases, it will be possible to weld steel
sections without any special preparation. For
heavier sections and for repair work on castings,
etc., it will be necessary to cut or grind an angle
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between the pieces being joined to ensure proper
penetration of the weld metal and to produce
sound joints. In general, surfaces being welded
should be clean and free of rust, scale, dirt, grease,
etc. Slag should be removed from oxy-cut surfaces.
Typical joint designs are shown in Figure 1-19.
Open Square Butt Joint
(Fig 1-19a)
Gap varies from1.6mm (1/16")
to 4.8mm (3/16") depending on plate thickness
Single Vee Butt Joint
(Fig 1-19b)
Not less than 45˚
Single Vee Butt Joint
(Fig 1-19c)
Not less than 70˚
1.6mm (1/16")
Double Vee Butt Joint
(Fig 1-19d)
Not less than 70˚
1.6mm (1/16")
Lap Joint (Fig 1-19e)
Fillet Joint (Fig 1-19f)
1.6mm (1/16") max.
1.6mm (1/16") max.