Arc Welding
By Bob Arlt
2008
Purpose of this Presentation
Introduce common welding terms
Show necessary equipment for arc
welding
Explain how it works
Demonstrate safe and correct operation of
the arc welder
Arc Welding is also known as:
SMAW (Shielded
Metal Arc Welding)
Stick Welding (since it
uses an electrode)
Manual Arc Welding
Welder
Most newer arc
welders are AC/DC
Higher amperage
machines can weld
thicker metal
They have 2 leads (or
cables)
Ground (also known
as the “work”)
Electrode holder (or
“stinger”)
How it Works
Think of the arc as
lightning, trying to get
to the ground
The electricity flows
from the welder,
through the electrode
and across the arc,
through the base
material to the ground
lead and back to the
welder
The electric arc is
established in the
space between the
end of the electrode
and the work
The arc reaches
temperatures of
10,000°F which melts
the electrode and
base material
As the core rod, flux
coating, and work
pieces heat up and
melt, they form a pool
of molten material
called a weld puddle
This puddle is used to
join pieces of metal
together
Electrodes
Are consumable – they get melted during
the welding process
Are made of two parts
Core Rod (Metal Filler)
Carries welding current and becomes part
of the weld
Flux Coating
Flux Coating
Makes it easier to start the arc
Provides a shielding gas to protect the weld from
impurities
Forms a slag (combination of flux and impurities
that float to the surface of the weld)
This coating slows the cooling rate of the weld and
can be chipped off and cleaned with a wire brush
Electrode Numbering
E6013
The prefix “E”designates an arc welding electrode
The first 2 numbers are tensile strength (60,000 psi)
3rd number is position (1 is all position, 2 is flat and
horizontal only)
4th number (combined with 3rd) indicate type of coating
and polarity.
numbering explained
Welder Settings
Amperage – this is the current, or “heat of the
welder”
The thicker the metal, the higher the current should
be set
Polarity – the direction of the current flow
Different Polarities
AC alternating current
DC+ direct current, reverse polarity.
Current flows from electrode to base
metal. This is most common
DC- direct current, strait polarity. Current
flows from base metal to electrode. Good
for thinner metal
How to Get Good Welds!
Correct settings – amperage, polarity
Proper electrode
Type of metal and thickness
Electrode angle, travel speed, and arc length
Electrode Angle
20 to 30 degrees.
Drag the electrode –
do not “push”!
Make sure you are in
line with the bead
direction
Travel Speed
The speed at which the electrode moves along
the base material while welding
Too fast of a travel speed results in a skinny and convex weld
Too slow of a travel speed results in a wide weld with an
excessive metal deposit
Arc Length
The distance the
electrode is from the
base metal. It should
match the electrode
diameter
Too close and the
Arc Length = 1/8”
bead will appear
skinny and electrode
may stick to the metal
Too far and you’ll have
excessive spatter and
no bead at all
Starting the Weld
Known as “striking an
arc”
Similar to striking a
match
You must have the
electrode moving
before it touches the
base metal -
otherwise, it’ll stick
Once you can see, go
to the starting point
and start your bead
Weld Positions
Flat is the easiest
position
Whenever possible,
adjust your metal
Vertical, Horizontal,
and Overhead welds
are much more difficult
Safety
Protect yourself
and others from
potential hazards
including:
Fumes and Gases
Electric Shock
Arc Rays
Fire and Explosion
Hazards
Noise
Hot objects
Proper Dress
Leather gloves
Helmet with a #10 shade lens
Apron and/or jacket
Boots
Check Your Work Area
For proper ventilation
For fire and explosion
hazards
For electrical
problems
For excessive noise
Now it’s Your Turn
The more you practice, the better you’ll get
Make sure you use 2 hands and are
comfortable
The biggest problems for beginners are:
Striking the arc (it wants to stick)
Traveling too fast
Too far away
Resources
http://www.lincolnelectric.com/knowledge/t
raining/weldcurriculum.asp
http://en.wikipedia.org/wiki/Arc_welding