1. SMAW - Shielded Metal Arc Welding
Definition – Producing an arc between base metal and a consumable, flux covered metal electrode. The electrode acts as an electrical conductor and a filler metal.

2. SMAW Advantages Equipment less complex, more portable and less costly
Can be done indoors or outdoors, in any location and any position
Electrodes available to match properties and strength of most base metals
Not used for welding softer metals
Not as efficient in deposition

3. Requirements to Arc Welding
Power Source – Either AC or DC
Electrode Holder (Stinger) and Cable
Work Clamp and Cable
Electrode
Base Metal

4. SMAW Operating Principles
Sets up electric circuit
Includes welding machine, work, electric cables, electrode holder and electrodes, and a work clamp
Heat of electric arc brings work to be welded and consumable electrode to molten state
Heat intense: as high at 9,000ºF at center

5. Starting, Stopping and Adjusting
Never start the machines under a load
On/Off Switch
Amperage (current) set up by control knob – can be adjusted while welding
Voltage – controlled by the length of the arc gap
- small arc gap = less voltage (cold)
- large arc gap = more voltage (hot)

6. Electrodes First Letter – “E” is Electric Arc Welding
“ER” is used for Gas Welding
First 2 or 3 digits provide the tensile strength in thousands of lbs / in squared
2nd digit from the right – recommended position
1 – All Positions
2 – Flat or Horizontal
4 – Flat, Horizontal, overhead,
and downhill welding

7. Electrodes Cont…
Last two numbers together represent proper application and covering composition
EXX11 – High – cellulose, potassium
EXX13 – High-titania, potassium
EXX18 – Iron Powder, Low-hydrogen, potassium
0,1
Fast Freeze Rod
2-9
Filler Rod

8. Electrodes Cont… As the Electrode melts it accomplishes two tasks
Provides Filler Material
- Deposition – How much metal is deposited in the weld.
Flux – Creates a gas that shields the weld and lays down “slag” to allow the weld to cool slowly and remain pure

11. Striking an Arc
Electrode must first strike the base metal then be withdrawn to the correct arc distance or length.
Stabilizing the Arc
When first starting the Electrode might stick
This is because the arc length is too small
When welding with thin metal – lift the electrode and base metal off of the table
When welding thicker (heavier) metal – release the electrode from the stinger
When the arc length is too great the arc will go out

12. Striking an Arc Cont…
In order to produce a weld you need to be able to stabilize the arc and create a pool
Scratching Method
Bump Method

13. Running a Bead
After establishing a stable arc we are ready to create a weld bead
To “run” a good bead requires 4 things
Arc Gap distance or Arc Length
Speed of Travel
Correct Amperage
Electrode Angle – 15 to 20 degrees in direction of travel

14. Arc Welding Joints
Butt
Lapp
Corner
T-Joint
Edge

15. AC Versus DC Power
Direct Current

16. AC Versus DC Power
NO Current

17. AC Versus DC Power
Alternating Current

18. Safety Hazards Radiation from the arc: Ultraviolet and Infrared rays
Flying Sparks and molten globules
Electric Shock
Fumes
Burns

19. Safety Cont…
Never look at an arc from any distance unless your eyes are protected
Welding Helmets – shade 10 lens
Protects more than just your eyes!
Face, hands, arms, and other skin surfaces must be protected – burns are comparable to sun burns

20. Safety Cont… Flammable Materials Avoid welding in wet or damp areas
Always weld in areas that are well ventilated

21. Protective Clothing
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22. Procedures
Make sure you have all safety materials – gloves, clothing, safety glasses, welding helmets
Electrode Check-out procedures
Partners
Metal

23. Procedures Cont… Use pliers or tongs to handle hot metal
When leaving hot metal lying around please mark on it with a piece of soapstone – HOT
Don’t ever under any circumstances hand me a piece of hot metal!!
Use the tanks outside to cool off metal