1. Arc Welding
Basic Safety

2. Warnings
Welding can be safe when proper measures are taken to protect yourself and others from potential hazards.
Understand and follow all warning labels found on equipment and with all consumables.

3. Potential Hazards
Protect yourself and others from potential hazards including:
Fumes and Gases
Electric Shock
Arc Rays
Fire and Explosion Hazards
Noise
Hot objects
Welding Sparks

4. Fumes and Gases
Welding fumes can be harmful to the welder causing implications such as:
Irritation of the respiratory tract
Metal fume fever
Slightly increase the risk of lung cancer
Use enough ventilation, exhaust at the arc, or both, to keep fumes and gases from your breathing zone and the general area
Use a respirator if needed or required by the process.
The ventilation system must be on while welding at all times.

5. Electrical Shock Electric shock can kill
Do not touch live electrical parts
Primary Voltage – , volt input power
Secondary Voltage – 6 to 100 volts for welding
Insulate yourself from work and ground
Follow all warnings on welding equipment
Wear insulated clothing
Always shut off machinery when done and roll the cords up neatly
Do not make repairs yourself, alert your instructor immediately!

6. U.V. Rays
Welding will produce ultraviolet rays that are harmful to the human eye and skin. Proper protection is needed to avoid bodily harm.
Arc rays are ten times brighter than the sun and can injure eyes and burn skin
Precaution must be taken to protect your eyes and skin from UV radiation. The welding arc is brighter than the sun
Wear correct eye and body protection
10 shade helmet
Safety Glasses under the helmet
Gloves
Arm and Body Protection
Jacket
Shoulder Covers
Coveralls

7. Fire Hazards and Material Safety
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
Always clean painted materials
All welding booths should be cleaned thoroughly
Have a fire extinguisher ready
Inspect area for fires 30 minutes after welding
Watch for sharp metal edges
Cool all welded metal in the water tank.

8. Ear Protection Loud noises can damage your hearing
Keep loud noises at a safe level by using proper hearing protection such as:
Ear plugs
Ear muffs

9. 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, shirts jackets, bibs, and fire-proof pants
Welding cap, helmet and safety glasses
Ear protection – ear plugs and muffs
Most importantly safety glasses are to be worn at all times in the shop

10. Improper Protective Clothing
List and describe
what is wrong
in this picture

11. Basic Electricity and Welding
Arc Welding
Basic Safety

12. Arc Welding Circuit and Concept
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.
Identify all the above parts for the arc welder, describe the function of each part, and determine each of the parts safety aspects.

13. Electrical Concepts
DC -
DC +
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)
ALWAYS REMEMBER THAT VOLTAGE WILL HURT BUT AMPERAGE CAN BE FATAL AC

14. Electrical Lead Condition
Before starting an operation, always check the condition of all electrical leads.
Cracked and worn leads can lead to fatal shock.
All electrode holders or “stingers” should be in tack and not cracked or missing pieces.
All plugs and outlets should be in tack. Never set-up a welder with a broken plug or into a broken outlet.
Never operate a welder with splices showing in the leads.

15. Shielded Metal Arc Welding
SMAW

16. SMAW Process

17. SMAW Key Parts
Electrode Holder: Also known as the “stinger” Handle-like tool that holds the electrode while welding.
Never hold this part with your bare hand while welding.
Ground Connection: Also known as the “workpiece connection clamp” that connects to the work to complete the electrical circuit
Power Source: Where the welder plugs into
Amperage Scale: Determines the amount of “heat” or power the welder will operate at.
Polarity Switch: Setting that determines how the electrons will flow during the welding process.
On / Off Switch: Turns the welder on / off. Make sure the switch function properly at all times.

18. SMAW Principles
The American Welding Society defines SMAW as Shielded Metal Arc Welding
SMAW:
Is commonly known as ‘Stick’ welding or manual arc welding
Is the most widely used arc welding process in the world
Can be used to weld most common metals and alloys

19. SMAW Welding Circuit
Current flows through the electrode cable, to the electrode holder, through the electrode, and across the arc
On the work side of the arc, the current flows through the base material to the work clamp and back to the welding machine

20. SMAW Process
Identify all the above segments for the SMAW process, describe the function of each segment, and determine if any safety aspects exist.

21. The Electrode What is it?
Is a consumable - it gets melted during the welding process
Is composed of two parts
Core Rod (Metal Filler)
Carries welding current
Becomes part of the weld
Flux Coating
Produces a shielding gas
Can provide additional filler
Forms a slag

22. Electrode Classification
Electrodes are classified by a numbering system
E6013
E = Electrode
60 or first two numbers = Tensile strength (thousands of pounds
1 or third number = Welding position
3 or fourth number = Welding current type and depth of weld penetration.
Pictured above are E-7018 electrodes. Identify what the tensile strength is for this electrode.

23. Electrode Classification Third Digit
E_ _ 1 _ = Usable in all directions
E_ _ 2 _ = Usable in flat and horizontal positions only
E_ _ 4 _ = Usable for vertical down only
Pictured above are E-6011 electrodes. Identify what each digit resembles up to the third digit.

24. Electrode Classification Fourth Digit
E_ _ _ 0 = DC reverse polarity only
E_ _ _ 1 = AC and DC reverse polarity
E_ _ _ 2 = AC and DC straight polarity
E_ _ _ 3 = AC and DC
E_ _ _ 4 = AC and DC
E_ _ _ 5 = DC reverse polarity
E_ _ _ 6 = AC and DC reverse polarity
E_ _ _ 8 = AC and DC reverse polarity
Pictured above are E-6013 electrodes. Identify what each digit resembles.

25. The Arc
An arc occurs when the electrode comes in contact with the work-piece and completes the circuit … like turning on a light!
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
Don’t look at the arc without proper eye protection.
Wear proper body protection. The UV rays will cause bodily harm.
Arc burning off the electrode

27. Weld Puddle
As the core rod, flux coating, and work pieces heat up and melt, they form a pool of molten material called a weld puddle
The weld puddle is what a welder watches and manipulates while welding
Don’t touch the hot puddle!!! The metal is hot!!!

28. Shielding Gas A shielding gas is formed when the flux coating melts.2 3
Shielding Gas 4
A shielding gas is formed when the flux coating melts.
This protects the weld puddle from the atmosphere preventing contamination during the molten state
Don’t touch the metal!!! The metal is hot!!!
Shielding gas can cause bodily harm. Be sure proper ventilation is being used.
The shielding gas protects the molten puddle from the atmosphere while stabilizing the arc

29. Solidified Weldment
As the molten weld puddle solidifies, it forms a joint or connection between two pieces of base material
When done properly on steel, it results in a weld stronger than the surrounding base metal
Don’t touch the metal!!! The metal is hot!!!

30. Slag
Slag is a combination of the flux coating and impurities from the base metal that float to the surface of the weld.
Slag quickly solidifies to form a solid coating which slows the cooling rate of the weld
The slag can be chipped away and cleaned with a wire brush when hard
Don’t touch the metal!!! The metal is hot!!!
Slag can be dangerous when being removed. Wear the proper safety protection.
This welder chips the slag off of a weld during the repair of railroad tracks

31. OXY ACETYLENE
SET-UP

32. Terms and Definitions
Backfire: A short pop of the torch flame followed by extinguishing of the flame or continued burning of the gases.
Flashback: when the torch flame moves into or beyond the mixing chamber.
Preheating: Heating prior to a welding or cutting operation

33. Equipment Required Oxygen cylinder Acetylene cylinder
Pressure regulators
Two hoses encased together
Welding torch with tips
Welding goggles and safety glasses
Striker
Check valves to prevent flashback

34. Acetylene Regulator

35. Oxygen Regulator

36. Typical Torch

37. Torch Parts

38. Striker

39. Cutting Tip

40. Welding and Heating Tips

41. Check Valves

42. Safety Rules for Oxy-Acetylene Workplace
Keep the work area free of grease, oil, and flammable materials
Cool or quench hot metal and extinguish all sparks before leaving. Sparks can travel up to 35 feet.
Don’t leave torches, or hot metal where someone will pick them up
Never carry matches or lighters into any work area

43. Pressure Gauge Failure

44. Cracked Acetylene Hose

45. Improper Storage of Tanks

46. Oxygen/ Acetylene Cutting Torch Stored on Unsafe Cart

47. Oxygen/ Acetylene Cutting Torch Stored in Flammable Liquids Cabinet

48. Regulator Parts
Pressure regulators reduce the supply pressure, indicated by the high pressure gauge to suitable working pressure, indicated by the low pressure gauge. By turning the adjusting screw, proper working pressures can be achieved.

49. Personal Safety Shirts Pants or Coveralls Shoes Gloves Safety Glasses
keep collar and sleeves buttoned to keep out sparks. Avoid wearing shirts with pockets.
Pants or Coveralls
no cuffs and come over shoe tops
Shoes
leather, cover entire foot
Gloves
Leather, never use to pick up metal
Safety Glasses
worn under helmets and goggles and all times.

50. Eye Protection Wear safety glasses at all times
Wear welding goggles or a face shield with a lens no. 4-6 while using torch equipment
when in doubt start with too dark of a lens and then switch to a lighter one.

51. Color Codes
Green = Oxygen
Red = Acetylene

52. Pressure Regulating Valves
Each regulator has two gauges mounted on a single manifold. One indicates cylinder pressure and the other indicates working pressure for the torch.
Each regulator has an adjusting screw or T-screw, so pressure to the torch can be quickly controlled by turning the screw righty-tighty to increases pressure and left-loosey to decrease pressure.

53. Regulator Attachment
Acetylene connectors have a V-groove left handed thread
Oxygen connectors have a plain surface right handed thread

54. PSI Settings Acetylene = 15 psi. max Oxygen = 40 psi. max
Over 15 psi. can be fatal
Our regulators in the lab will be set at 7 psi. max.
Oxygen = 40 psi. max
Over 40 psi. will dilute the heat of the flame
Our regulators in the lab will be set at 30 psi. max.

55. Torch Parts
Torch body is the part of the torch that is held like a pencil. It contains two needle valves to control the flow of gas
The welding head contains a mixer, mixing throat, and the welding tip

56. Types of Flames Oxidizing Neutral
Excess oxygen with no feather, makes hissing sound. Sounds like an angry snake.
Least used for anything
Neutral
Burns equal amounts of oxygen and acetylene and has a clear edged inner cone
Most used

57. Types of Flames Carburizing
Excess acetylene with an acetylene feather two to three times the length of the inner cone
While burning it will produce a heavy black smoke flame
Used some in hardsurfacing, adds carbon to metal

58. Operation Safety
1. Before you start make sure personal safety is followed.
2. Make sure you have had instruction
3. Release adjusting screw on regulators before opening valves
4. Stand on the opposite side of the regulator when opening a valve
5. Open cylinder valve slowly, oxygen first all the way open acetylene just a quarter of a turn

59. Operation Safety (II)
6. Do not use or compress acetylene at pressures higher than 15 psi.
7. Set working pressures as desired.
Acetylene: 10 psi for NCWHS lab
Oxygen: 30 psi for NCWHS lab
8. Light acetylene first 9. Never use oil on regulators or any equipment
If oil mixes or touches the acetylene it will combust
10. Do not use compressed air as a substitute for oxygen
11. Keep heat, flames, and sparks away from combustibles.
12. Keep hoses out of sparks or spatter to prevent leaks

60. Safety Lighting the Torch
Check the torch valves to make sure they are closed
Open the oxygen tank valve full open
Open the acetylene tank valve ¼ turn
Turn on the oxygen knob on the torch body
This is located next to the acetylene knob
Turn the acetylene gas on no more than ¼ turn
Strike and light
Mix oxygen into the flame with the mixing knob on the torch body. While mixing you want to create a neutral flame. Press down on the cutting lever also to make sure the flame does not jump.
The mixing knob is located half-way up the torch body next to the cutting lever

61. Shutting down the unit
Shut down the flame by turning off the acetylene knob on the torch body.
Close the oxygen mixing knob located half-way up the torch body
Shut off the tanks by closing the tank valves
Open the acetylene to purge or bleed the line
When both gauges read zero, close the valve
Open the oxygen valve
Release pressure on the regulators by turning adjusting screw left or T-screw (out). DO NOT remove the T-screw
Coil hoses and put tools away