METAL TOOLS LEVEL 2

MIG WELDING

HOUSEKEEPING

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1. Land acknowledgement
2. Personal Intro and Pronouns
3. Waivers
4. Structure
1. 30 min presentation
2. 2:30 workshop time
5. Bathrooms

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Class timing

SESSION OVERVIEW

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Goals:

1. Welding orientation
2. To make you into a confident a safe MIG welder
3. Practice welds
4. Troubleshooting

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PROGRAM OVERVIEW

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1

GENERAL SHOP EXPECTATIONS

General Shop Expectations

Body position

Welding theory

Exercise

WORKING WITH OTHERS

• Warning others when striking an arc - shout “EYES!”
• Be aware of your surroundings
• Communicate your intentions
• Being respectful of other projects
• Being responsible for your own work
• Label your project materials
• Store your work to take up as little space as possible
• Clean up your work area and left over finishing materials

END OF SESSION EXPECTATIONS

• Allow enough time to clean up!
• Sweep
• Reorganize tools
• Leave the space better than you found it
• Look for general cleanup tasks that need to happen
• Label your work
• Don’t clean for yourself, clean for the next member

PPE FOR METALWORKING

• Glasses (Polycarbonate)
• Ear Protection
• Respirator for fumes (recommended)
• Welding helmet
• Face Shield for grinding

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Other considerations

• Tie Back hair
• No loose clothing
• No synthetic clothing
• No Jewelry
• No gloves on machines
• Good footwear (Leather, closed toe)

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2

BODY POSITION

General Shop Expectations

Body position

Welding theory

Exercise

BODY POSITION

Stance

• Bent knees
• Staggered feet
• Centered weight
• Mindful of tool slipping or kickback
• Position your face away from smoke if possible

Ergonomics

• Position your body to allow for arm movement
• Brace yourself for steady welding
• Set up material and workspace to reduce awkward positioning

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3

WELDING THEORY

General Shop Expectations

Body position

Welding theory

Exercise

HAZARDS

• Electrical Shocks
• Hot material (Weld puddle is around 6000⁰C)
• Toxic fumes (Never use brake cleaner)
• Arc Flash (Make sure to warn other around before striking an arc and draw red curtains)
• Pressurized gas bottles and compressed air
• Fires

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WELDING SETUP

• Select proper welding type for task and material
• Adjust welding machine properly depending on material type, thickness and fit-up
• Use proper and safe welding technique
• Make sure the area is safe for welding

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TYPES OF WELDING

PARTS OF A MIG WELDER

• DC Machine (CV)
• Gas bottle, gas regulator and hose
• Wire spool and rollers
• Welding whip and gun
• Ground clamp

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MIG WELDING

• Can be done in all positions
• Most common wire for steel is 70S-6 (supplied by Create)
• Semi-automatic welding process
• Most common gases are Pure Argon, Argon and CO2 mixture and Pure CO2. We use 75% Argon, 25 CO2.

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TRAVEL ANGLE

Welding can be done pulling or pushing with a travel angle between 10⁰ and 30⁰

10^o to 30^o

GOOD WELDS

• Smooth, continuous and uniform.
• No weld defects

WELD DEFECTS

• Porosity
• Cracking
• Undercut

4

EXERCISE

General Shop Expectations

Body position

Welding theory

Exercise

PRACTICE WELDS

Top view

Side view

2. Butt Weld

3. Fillet Weld

2”

8”

1. Straight beads

4”

2”

2”

EXERCISE FLOW

5

MEMBERSHIP

Membership

Section 1 title

Section 2 title

Section 3 title

Section 4 title

AS A SPECIAL THANK YOU FOR JOINING US TODAY

Get 50% off your first month when committing to 3 months of membership.

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(See our front desk after the class for more details)

ANY QUESTIONS?

METAL TOOLS LEVEL 2

Type of welding machines

• DC or AC (Stick only)
• DC machines are either CC (constant current) or CV (constant voltage) depending on the welding process. Some Can do both
• Welding polarity: EP (Electrode positive) or EN (Electrode negative)

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Advantages:

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• Versatile
• Wide range of filler material
• Portable

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Disadvantage

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• Only 60 to 70% of material becomes deposit
• Smoky
• Needs after weld clean up
• Slower welding

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Stick welding

SMAW (Shielded metal arc welding)

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Advantages:

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• Versatile
• Wide range of filler material available
• High deposit rate ( 92 to 98% of filler become deposit)
• Continuous feed mechanism (Semi-Automatic)
• Very clean process (Minimal post cleaning, low smoke)

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Disadvantage

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• Gas bottle required
• More chance for weld defects ( Porosity)
• Limited to whip length
• More expensive setup

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Mig welding

GMAW (Gas metal arc welding)

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Stick welding

SMAW (Shielded metal arc welding)

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• Parts of a welding machine
• DC Machine
• Electrode holder and lead
• Ground clamp and lead
• The Electrode holder (Stinger) is connected to the Positive pole
• The ground clamp is connected to the Negative pole
• Once the electrode makes contact with the workpiece it strikes an arc and welding begins
• Welding is achieved by melting the “Rod” into the weld puddle

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• Stick welding can be done in any positions
• Most common electrode for steel is 7018 and they come in different sizes
• Welding must be done pulling the rod with a travel angle between 10⁰ to 20⁰
• Work angle is usually 90⁰ or 45⁰
• Electrodes are covered with flux that melt into the weld puddle and protect it from ambient air. As it cools down it turns into solid slag
• Travel speed affects the bead size and profile
• Arc length should be kept short, rule of thumb is equal to electrode core diameter

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Stick welding

SMAW (Shielded metal arc welding)

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4

Plasma Cutting

General Shop Expectations

Body position

Welding theory

Plasma cutting

Plasma cutting

PAC (Plasma arc cutting)

• Parts of a Plasma cutting machine
• Power Source (DCEN)
• Compressed air and air line
• Whip and cutting torch
• Ground clamp and lead

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• Advantages
• Versatile (can cut any material)
• Portable
• Cuts very fast (minimal distortion)
• Clean cuts

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Plasma cutting

PAC (Plasma arc cutting)

• Plasma operates by transforming gas into plasma. Plasma is a 4th state after liquid, solid and gas. It’s created by superheating a gas so that its molecules are torn apart into ionized atoms. It generates temperatures up to 33000⁰C.
• Once the trigger is pressed a pilot arc strikes for ~2 seconds. The cutting arc will only start if the tip is close enough to the work piece.
• Maintain a short stand off ( Tip to work distance) of about 1/8” with the work piece.
• Pulling rather than pushing makes cutting easier.
• Set air pressure to around ~75 psi

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