Shielded Metal Arc Welding Quarter 1 Lesson Compilation

1. 1
Welding Safety

2. 2
• Welding can be safe when sufficient measures are
taken to protect yourself and others from potential
hazards
• Students should read and understand the following
before welding:
– Warning Labels
– Material Safety Data Sheets (MSDS)
• Students should also be familiar with the following
information
– ‘Safety in Welding, Cutting, and Allied Processes’ (ANSI Z49.1)
– Lincoln Electric’s ‘Arc Welding Safety’ (E205)
Arc Welding Safety

3. 3
Warning Labels
• Understand and
follow all warning
labels found:
– On welding equipment
– With all consumable
packaging
– Within instruction
manuals

4. 4
Sign is a Language

5. 5
Classification of
Safety Signs

6. 6
Danger
• Used to indicate an
imminently hazardous
situation which, if not
avoided, will result in
death or serious injury.
• The use of this signal
word should be limited to
the most extreme
situations.

7. 7
Warning
• This indicates a
potentially hazardous
situation which, if not
avoided, could result
in death or serious
injury.

8. 8
Caution
• Used to indicate a
potentially hazardous
situation which, if not
avoided, may result in
minor or moderate injury.
• CAUTION may also be
used without the safety
color symbol (the triangle
with exclamation mark) to
indicate property-
damage-only.

9. 9
Prohibition
• Prohibitions signs are
there to tell you not to do
something.
• They are a danger sign,
telling you that it is not
safe to proceed.
• These signs have a red
circle with a red diagonal
line through it. The
pictogram is black on a
white background.

10. 10
Mandatory
• Mandatory signs are
there to tell you to do
something.
• These signs are round in
shape. The pictogram is
white on a blue
background. The circle
usually has a white
border.

11. 11
Fire Signs
• advice the location of fire
alarms and firefighting
equipment
• Fire signs are square or
rectangular in shape and
contain a white symbol
and/or text on a red
background.

12. 12
Emergency Information Signs
• indicate the location of,
or direction to,
emergency- related
facilities (exits, first aid,
safety equipment, etc.)
• These signs feature a
white symbol and/or text
on a green background.

13. 13
Welding Hazards

14. 14
Arc Welding Safety
• Protect yourself and
others from potential
hazards including:
– Fumes and Gases
– Electric Shock
– Arc Rays
– Fire and Explosion
Hazards
– Noise
– Hot objects

15. 15
Fumes and Gases
• Fumes and gases can be
hazardous to your health
• Keep your head out of the
fumes
• Use enough ventilation, exhaust
at the arc, or both, to keep
fumes and gases from your
breathing zone and the general
area
• Prolonged exposure to welding
fume may cause lung damage
and various types of cancer,
including lung, larynx and
urinary tract.

16. 16
Fumes and Gases
• Clean welding surfaces regularly to
remove coatings that could potentially
result in toxic exposure levels.
• Stay upwind of welding fumes when
working in open or outdoor areas. Be
aware, however, that working
outdoors or in open work
environments doesn’t guarantee safe
ventilation.
• Use local exhaust ventilation systems
for indoor welding. Be sure to keep
exhaust ports away from other
workers.
• Never weld in a confined space that
doesn’t have ventilation.
• Wear respiratory protection if
ventilation and work practices don’t
adequately reduce welding fume
exposure to safe levels.

17. 17
Electric Shock
• Electric shock can kill
• Do not touch live electrical
parts
– Primary Voltage –230, 460
volt input power
– Secondary Voltage – 6 to
100 volts for welding
• Insulate yourself from
work and ground
• Follow all warnings on
welding equipment
Do not make repairs
yourself, alert your
instructor immediately!

18. 18
Electric Shock
You are particularly at risk if you
work in electrically hazardous
conditions. These include
welding:
• In damp conditions.
• While wearing wet clothing.
• On metal flooring or
structures.
• In cramped conditions where
you are required to lie, kneel
or crouch.

19. 19
Arc Rays
• Arc rays can injure eyes
and burn skin
• The welding arc is
brighter than the sun
• Precaution must be taken
to protect your eyes and
skin from UV radiation
• Wear correct eye and
body protection

20. 20
BURN CAUSED BY LIGHT
• Ultra violet light- can
cause first degree or
second degree burn to
the eyes and skin
• Infrared – wave that is
felt as heat
• Visible light- light that we
see (producer of varying
quantities and color)

21. 21
Arc Eyes
Certain types of UV radiation
can produce an injury to the
surface and mucous membrane
(conjunctiva) of the eye called
"arc eye," "welders' eye" or "arc
flash." These names are
common names for
"conjunctivitis" - an inflammation
of the mucous membrane of the
front of the eye.

22. 22
Arc Eyes Symptoms
• pain - ranging from a mild
feeling of pressure in the
eyes to intense pain in severe
instances
• tearing and reddening of the
eye and membranes around
the eye (bloodshot)
• sensation of "sand in the eye"
• abnormal sensitivity to light
• inability to look at light
sources (photophobia)

23. 23
Burns
Welding arcs and flames emit
intense visible, ultraviolet, and
infrared radiation.
• UV radiation in a welding arc will burn
unprotected skin just like UV radiation
in sunlight. This hazard is true for
direct exposure to UV radiation as
well as radiation that is reflected from
metal surfaces, walls, and ceilings.
• Long-term exposure to UV radiation
can cause skin cancer.
• Infrared radiation and visible light
normally have very little effect on the
skin.

24. 24
Fire and Explosion Hazards
• Welding sparks can cause
fires and explosions
• Sparks and spatter from the
welding arc can spray up to
35 feet from your work
• Flammable materials should
be removed from the welding
area or shielded from sparks
and spatter
• Have a fire extinguisher ready
• Inspect area for fires 30
minutes after welding

25. 25
Classification of Fires
Flammable materials around
the working area are the
number one cause of a fire.
This can be prevented by
maintaining a clean working
area before proceeding to
weld and these other safety
controls. It is also important to
know the location of fire
alarms, emergency exits, and
fire extinguishers in the event
of a fire.

26. 26
Classification of Fires

27. 27
Physical Hazards
• factor or circumstance that can
cause harm with contact
• can cause burns, eye damage, cuts,
and crushed toes and fingers are
ever-present when welding
• Other welding-related dangers
include noise; ergonomic problems
from awkward body positions and
repetitive stress; and slips, trips or
falls resulting from hoses or other
equipment laying on the ground

28. 28
Noise
• Noise is one of the most common
occupational health hazards
• Loud noises can damage your
hearing
• Exposure to loud noise kills the
nerve endings in our inner ear. More
exposure will result in more dead
nerve endings.
• The result is permanent hearing loss
that cannot be corrected through
surgery or with medicine.

29. 29
Personal Protective
Equipment

30. 30
Protective Clothing
Personal protective equipment,
commonly referred to as "PPE", is
equipment worn to minimize
exposure to hazards that cause
serious workplace injuries and
illnesses. These injuries and
illnesses may result from contact
with chemical, radiological,
physical, electrical, mechanical, or
other workplace hazards.

31. 31
Protective Clothing
Welders must wear protective
clothing for
– Protection from sparks, spatter and UV
radiation
– Insulation from electric shock
• Protective clothing includes …
– Fire-proof clothing without rolled sleeves,
cuffs or frays
– Work boots
– Welding gloves, jackets, bibs, and fire-
proof pants
– Welding cap, helmet and safety glasses
– Ear protection – ear plugs and muffs

32. Welding Shield/Helmet
• Welding shield/helmet is used
to protect our face and eyes
from the arc rays and heat,
and the spatter from molten
metal.
• The arc is viewed through a
filter which reduces the
intensity of radiation but allows
a safe amount of light to pass
for viewing the weld pool and
end of the electrode.
32

33. Welding helmet
• Helmet type welding
shield is more convenient
to use because it allows
both hands to work
freely.
Hand Shield
• Hand-held shield allows
only one hand to work
freely.
33

34. Welding leather jacket
• Leather jacket is made of
chrome leather and
prevents the entry of
sparks between our
clothes and body.
34

35. Welding leather apron
• is made of chrome
leather and provides a
welder with complete
protection of his chest to
mid calf from sparks and
hot metal
35

36. Welding gloves/gauntlet
• Welding gloves/gauntlet
is made of chrome
leather and protects our
hands from heat, spatter,
and radiations.
36

37. Face Shield/Safety Shield
• Face shield is designed
to protect the wearer
from specific hazards
that may affect the face.
• Depending on the type
used, a face shield may
protect its wearer from a
physical hazard, energy
or radiation, chemical
splashes, or biological
hazards.
37

38. Welding Leggings and Spats
• Welding leggings protect the
lower leg (from the knee
down) from sparks and
spatter. Leather is naturally
abrasion and flame resistant
for use in applications with
heavy sparks and spatter.
• Welding spats protect the
ankle and the top of footwear
from sparks and spatter.
Leather is naturally abrasion
and flame resistant for use in
applications with heavy sparks
and spatter.
38

39. Protective cover all
• Welding coveralls are
worn over personal
clothing or other
protective clothing to
provide continuous
coverage and prevent
gaps at the waist when
moving or bending.
• made from light asbestos
coated with aluminum to
protect the whole body
during welding
39

40. Leather sleeves
• Welding sleeves and capes
are worn on the arms or
upper torso to protect arms
from sparks and flames
encountered during welding
• They are made of leather,
treated fabrics, or other
heat- and spark-resistant
materials.
• Welding sleeves are worn
with welding gloves and
other protective clothing as
needed.
40

41. Welding safety shoes
• have heat resistant soles
and impact resistant toes
• It helps prevent foot
injuries due to slippery
surface, heavy falling or
rolling objects, sharp
piercing edges, pinch
points, rotary machinery,
hot objects, loops of
ropes under tension,
splinters, electricity,
chemicals
41

42. Safety goggles
• Welding glasses or
goggles are a type of
PPE that’s used by the
welders for providing
protection to their eyes
from intense ultraviolet,
heat, or infrared light plus
flying debris in times of
the welding as well as
cutting operations.
42

43. Earmuffs and earplugs
• Earmuffs are used for ear
coverings and are
connected by a flexible
band and worn as
protection against
extreme noise.
• Earplugs is a pair of
device that is meant to
be inserted in the ear
canal to protect the
wearer's ears from loud
noise or intrusion
43

44. Respirator
• Respirators is an
apparatus worn over the
mouth and nose or the
entire face to prevent the
inhalation of dust, smoke,
or other noxious
substances.
• Respirator masks
filter weld fumes and
particles from the air and
increase operator
comfort and safety
44

45. 45
Application Activity
• TIME TO PRACTICE
– Go out to the lab
– Demonstrate the use
of proper safety
precautions such as:
 Reading warnings
 Using proper protective
clothing
 Equipment inspection
 Keeping your head out
of the fume
 Proper ventilation

46. 46
Basic Electricity and
Welding

47. 47
The Arc Welding Circuit
• The electricity flows
from the power
source, through the
electrode and across
the arc, through the
base material to the
work lead and back
to the power source

48. 48
Basic Electricity
• Voltage – The electrical
potential or pressure that
causes current to flow
– Measured in Volts
• Current – The movement
of charged particles in a
specific direction
– Measured in Amps
• Polarity
– DC- (Direct Current
Electrode Negative)
– DC+ (Direct Current
Electrode Positive)
– AC (Alternating Current)
DC+
DC -
AC

49. 49
Types of Joints

50. 50
Types of Joints
• There are 5 types of
joints …

51. 51
Parts of a Weld

52. 52
Parts of a Weld
Joint and Weld
Heat Affected Zone

53. 53
Fillet and Groove Welds
• Groove and fillet welds can be made on many
types of joints

54. 54
Fillet Weld Inspection
• Fillet welds should:
– Have a flat to slightly convex face
– Be uniform in appearance
– Have equal leg size
– Have good wash-in into base materials
• This is an example of a good fillet weld:

55. 55
Welding Symbols

56. 56
What are Welding Symbols?
• Welding symbols give
the welder specific
instructions about the
weld including:
– Placement
– Size
– Length
– Process
– Any other special
notes
• Welding symbols are
– Universally used
– Governed by the AWS
– Found on engineering
drawings
“How to Read Shop Drawings”
available at www.jflf.org

57. 57
Welding Symbols
• Welding symbols contain information about the
weld to be made
– S – leg dimension of the weld
– Triangle – the weld is to be made on the arrow side of this joint
– Tail – any additional information required (i.e. position the weld
is to be made)
– Arrow - the joint the welding symbol applies to

58. 58
Welding Positions

59. 59
What are Welding Positions?
• There are various positions that a weld can be made in:

60. 60
Welder
Responsibilities

61. 61
What are the
Responsibilities of a Welder?
• Welders have many areas of
important responsibilities
• These relate to:
– Arc Welding Safety
– Knowledge – Content
– Attitude – Reactions
– Skills – Performance
– Work Habits – Daily Functions
Always keep safety in
mind when welding

62. 62
Arc Welding Safety
• A welder MUST always follow safe work
practices:
– Students should read and understand the following before
welding:
 Warning Labels
 Material Safety Data Sheets (MSDS)
– Students should also be familiar with the following information
 ‘Safety in Welding, Cutting, and Allied Processes’ (ANSI Z49.1)
 Lincoln Electric’s ‘Arc Welding Safety’ (E205)

63. 63
Knowledge - Content
• Welding can teach
you about….
– Science when applying
metallurgy, chemistry,
electricity, etc.
– Math when calculating
angles, joint design, and
weld size
– English when
communicating and
interpreting drawings,
codes, and procedures
– Technical areas when
performing the actual
welding applications
How much science and
math went into the
development of this bike?

64. 64
Attitude
• The best welders
demonstrate a can-do
attitude when performing
welding processes
• This means being able to…
– Work as a team member
– Communicate ideas to others
– Listen to opinions of others
– Promote a positive attitude
– Provide solutions to problems
– Take pride in workmanship
These welders work together
to inspect a weld.

65. 65
Skills/Performance
• A welder must
demonstrate technical
skills when performing
welding processes
• A welder must know how
to:
– Use hand tools and materials,
to operate equipment in a safe,
accurate, and consistent
manner
– Acquire and evaluate
information needed for
problem solving
– Complete quality work
– Maintain equipment
There is no room for poor
workmanship in NASCAR

66. 66
Work Habits/Daily Functions
• A welder must practice good
working habits when
performing welding
processes
• This means being able to …
– Follow detailed verbal and
written instructions
– Maintain workspace,
equipment, and tool
cleanliness
– Correctly fill out, maintain and
submit time cards, work
assignment cards, and other
records as required
– Follow safe working practices
Agriculture teachers brush
up on their welding skills at
Lincoln Electric’s Welding
Educator’s Workshop

67. 67
Welding Certification

68. 68
Welding Certification
• What is a welding certification?
– Welding certifications are used to test a welder’s knowledge and
welding skill
– Certifications are available for many different processes, materials, and
positions.
• Who certifies welders?
– Certification programs are offered by many different types of
organizations:
 Companies
 Skilled Trades
 Military
 Ship Builders
 Pipelines
 The American Welding Society

69. 69
Welding Certification
• How can you become certified?
– Certification testing is available at testing facilities all over the
United States
– The AWS offers many certifications including: welders, welding
inspectors, and welding educators
• What is the value of a welding certification?
– A welding certification proves that you have passed a test and are
qualified for the job
– As an AWS certified welder your name is kept in a national
database which is used to notify you of jobs open in your area
– It is a source of accomplishment and pride

70. 70
English, Math, and
Science Connection

71. 71
English, Math, and
Science Connection
• Many of the same concepts you learn in other
classes are practiced in welding. In what other
classes might you study the following terms?
 75/25 – gas mixture
 Volts
 Amps
 Degree/hr – cooling rate
 In/min
 Angles/degrees
 Metallurgy
 Fillet size
 Current
 Tension
 Compression
 Tensile strength
 Yield
 Blueprints
 Depth/width ratio
 Preheat temperature
 Cubic feet per hour

72. 72
National Academic Standards
Crosswalk
• The unit just completed has covered parts of
academic content listed in the National
Academic Standards as follows:
– NM-PROB.CONN.PK-12.3: Recognizes and applies
mathematics in contexts outside of mathematics.
– NLA-STANDARD 1: Uses the general skills and strategies of
the writing process.
– NLA-STANDARD 7: Uses reading skills and strategies to
understand and interpret a variety of informational texts.
– NS-PHYSICAL SCIENCE: (Experiences) interactions of energy
and matter.