Operating instructions

16
BOC Smootharc Advance II MIG 250C Operating manual
Electrodes and Typical Applications
Name AWS
Class.
Application
BOC Smootharc 13 E6013 A premium quality electrode for general
structural and sheet metal work in all
positions including vertical down using
low carbon steels
BOC Smootharc 24 E7024 An iron powder electrode for high
speed welding for H-V llets and at
butt joints. Medium to heavy structural
applications in low carbon steels
BOC Smootharc 18 E7018-1 A premium quality all positional
hydrogen controlled electrode for
carbon steels in pressure vessel
applications and where high integrity
welding is required and for free-
machining steels containing sulphur
BOC Smootharc S 308L E308L Rutile basic coated low carbon
electrodes for welding austenitic
stainless steel and di󹟾cult to weld
material
BOC Smootharc S 316L E316L
BOC Smootharc S 309L E309L Rutile basic coated low carbon electrode
for welding mild steel to stainless steel
and di󹟾cult to weld material
Electrode Size
The size of the electrode is generally dependent on the thickness of the
section being welded, and the larger the section the larger the electrode
required. In the case of light sheet the electrode size used is generally
slightly larger than the work being welded. This means that if 1.5 mm
sheet is being welded, 2.0 mm diameter electrode is the recommended
size. The following table gives the recommended maximum size of
electrodes that may be used for various thicknesses of section.
Recommended Electrode Sizes
Average Thickness
of Plate or Section
Maximum Recommended
Electrode Diameter
≤1.5 mm 2.0 mm
1.5–2.0 mm 2.5 mm
2.0–5.0 mm 3.15 mm
5.0–8.0 mm 4.0 mm
Welding Current
Correct current selection for a particular job is an important factor in arc
welding. With the current set too low, di󹟾culty is experienced in striking
and maintaining a stable arc. The electrode tends to stick to the work,
penetration is poor and beads with a distinct rounded prole will be
deposited.
Excessive current is accompanied by overheating of the electrode. It will
cause undercut, burning through of the material, and give excessive
spatter. Normal current for a particular job may be considered as the
maximum which can be used without burning through the work, over-
heating the electrode or producing a rough spattered surface, i.e. the
current in the middle of the range specied on the electrode package is
considered to be the optimum.
In the case of welding machines with separate terminals for di󹟽erent
size electrodes, ensure that the welding lead is connected to the correct
terminal for the size electrode being used. When using machines with
adjustable current, set on the current range specied.
The limits of this range should not normally be exceeded.
The following table shows the current ranges generally recommended
for BOC Smootharc13.