Lincoln Electric POWER-ARC 4000 - Manual (Page 34)

B-19 OPERATION B-19
POWER-ARC 4000
High-Speed Group (AWS E6013)
This group includes electrodes which have a moder-
ately forceful arc and deposit rates between those of
the out-of-position and high-deposit electrodes.
They are primarily general purpose production elec-
trodes especially for downhill fillets and laps or short
and irregular welds that change direction or position.
They are also widely used in maintenance and recom-
mended for sheet metal fillet and lap welds. Motion
“ D ” (see drawing) is generally used for vertical-up
welding, but motions “ A ” and “ B ” are also suitable.
Low Hydrogen Group (Stable-Arc E7018)
These electrodes are generally called “ low hydrogen ” .
The name comes from the fact that their coating
contains little hydrogen in either moisture or chemical
form. Low hydrogen electrodes offer these benefits:
outstanding crack resistance, lowest porosity on
sulphur bearing steels, and X-ray quality deposit capa-
bility. Thus, they are the first choice when welding
“ problem ” steels. E7018 can be used in all positions,
with Motion “ C ” (below) recommended for the first
pass on vertical-up welds. NEVER use a whipping
technique or a long arc with these electrodes.
ALWAYS fill craters by drawing electrode away slowly.
ALWAYS keep these electrodes dry. Electrodes,
when not used within a few hours after a container is
opened, must be stored in heated cabinets.
In some instances a back-up strip may be used and
plates may be gapped 1/8
” (3.2mm) or more, as
shown in figure (b).
On sections where only a sealed joint is required and
strength is not important, the joint may be welded after
slightly veeing out the seam as shown in figure (d)
below.
Selecting Electrodes
Which electrode is best for the particular job . . . how
do you use it? These are important questions
because the cost, quality, and appearance of your
work depends on proper electrode selection and appli-
cation. MILD STEEL ELECTRODES may be classi-
fied into the following groups:
Out-of-Position Group (AWS E6011)
This group includes electrodes which have a snappy,
deep penetrating arc and fast freezing deposits.
These electrodes are used for general purpose, all-
position fabrication and repair welding. They are also
the best choice for pipe welding and sheet metal butt,
corner, and edge welds. They can be used for repair
work when dirt, grease, plating or paint cannot be
completely cleaned from the steel. These electrodes
are typically used with motions
“ A ” and “ B ” (see draw-
ing) for the first pass on vertical-up welds.
Three ways to prepare plates where
complete penetration is necessary.
Scrap steel back-up strip
(a) (b) (c)
Single and double beads, with and without
beveling for tight, partial strength joints.
(d) (e)
Motions
START
SIDE
VIEW
F
G
E
D
C
B
A