Meridian Ag Department Course Information Packet Arc Welding (SMAW) Meridian Ag Department Course Information Packet Name:_____________________________________ Date:______________________________________

Shielded Metal Arc Welding SMAW (Stick) 1

What is SMAW? SMAW = Shielded Metal Arc Welding “Stick” Welding or “Manual” Welding Metal Rod Covered with Flux that Provides Shielding to Protect the Weld Uses Constant Current Power Sources Most Widely Used Arc Welding Process in the World 2

Shielded Metal Arc Welding An arc welding process with an arc between a covered electrode and the weld pool. The process is used with shielding from the decomposition of the electrode covering, without the application of pressure and with filler metal from the electrode.

Advantages Low Start Up Costs Portability Outdoor Weld ability 3

Advantages continued All Position Welding Variety of Materials Mechanical Properties

Limitations Low Efficiency (65%) Operating Factor Operator Skill Restarts 4

Limitations continued Amperage Limit Slag Spatter

Safety Eye & Ear Protection Welding Helmet with Lens Shade Number Welding Gloves & Optional Covering Proper Attire

Eye & Ear Protection Ear Plugs Goggles Safety Glasses Hearing Protectors

Proper Attire Long Sleeve At least 50% cotton No Cuffs

Welding Coverings Leather Welding Apron Leather Welding Jacket Leather Welding Gloves Leather Cape Sleeves/Bib Leather Welding Trousers

Welding Helmet

AWS/ANSI Lens Shade Numbers

Safety Electrical Hazards Fumes and Gases Arc Radiation Fire or Explosion Hazards in the Work Area

Be safety conscious at all times. ARC flash: ultra violet infrared visible Weld burns- wear gloves and coveralls

Electrical Hazards High Voltage Can Kill Electrical Shock Can Kill Do Not Operate With Covers Removed Disconnect Input Power Before Servicing Do Not Touch Electrically Live Parts Electrical Shock Can Kill Do Not Touch Electrode With Skin or Wet Clothing Insulate Yourself From Work and Ground

Fumes & Gases Welding May Produce Hazardous Fumes And Gases Shielding Gases Can Displace Air and May Cause Injury or Death Use Ventilation To Keep Air Breathing Zone Clear Do Not Weld Near Chlorinated Hydrocarbons

Arc Radiation Electric Arc Welding Rays Can Burn Eyes and Skin Always Use a Helmet When Arc Welding Select Appropriate Filter Lens Wear Appropriate Clothing Provide Non-Flammable Shielding to Protect Others

Fire or Explosion Remove Flammable Materials From The Welding Area Keep a Fire Extinguisher in the Welding Area Wear Fire Retardant Clothing Do Not Weld on Containers Which Have Held Combustible Materials

General Work Area Hazards Keep Power Source Cables, Welding Materials and Tools Neatly Organized Connect Work Cable as Close as Possible to the Weld Area Do Not Allow Alternative Circuits Through Scaffold Cables, Hoist Chains, or Ground Leads Use Only Properly Grounded Equipment Always Disconnect Power to Arc Welding Equipment Before Servicing

Types of Welders: I. Alternating current (AC) A. Advantages: pulls 37.5 amps of line draw current constant in either direction (oscillates) A. Advantages: Less initial cost B. Disadvantages: limited to localized area harder to strike an arc than DC fewer electrodes to choose from as DC

Types of Welders: II. Direct Current: A. Advantages (DC) current moves in on direction straight polarity- Electrodes negative reversed polarity- Electrodes positive A. Advantages (DC) mobile easier to strike an arc greater electrode selection easier to weld in all positions B. Disadvantages: high initial cost maintenance requirement larger in size than AC Bobcat™ 250 Trailblazer® 302

Types of Welders: III. AC. /D.C. Advantages of Both Welders for your use in our shop Dynasty® 200 Series Thunderbolt® XL 225/150 AC/DC Millermatic® 252

Maxstar 150s

SMAW Process Basics Electric Arc melts the electrode & fuses the joint Metal deposited Slag floats All Polarities

The SMAW Process Basics

Electrode Holders 200, 300, and 400 Amp Electrode Holders 13

Work Clamps 300 and 500 Amp Work Clamps GC 300 GC 500 13

AC Polarity Medium Penetration Medium Travel Speeds

DCEP (Reverse) Polarity Heat Concentrated at Work piece Forceful, Digging Arc Medium to Deep Penetration

DCEN (Straight) Polarity Heat Concentrated at Electrode Lower Penetration Increased Deposition Rates

Duty Cycle The Duty Cycle of a power source is the percentage of a ten (10) minute period that it can operate at the rated output current setting.

Duty Cycle Duty Cycle Amperes Time Available 30% 250 3 Min/10 Min 40% 225 4 Min/10 Min 50% 200 5 Min/10 Min 60% 190 6 Min/10 Min 70% 180 7 Min/10 Min 80% 170 8 Min/10 Min 90% 155 9 Min/10 Min 100% 140 10 Min/10 Min

Electrode information: E6013 (example) E- Electrode 60- 60,000 pound tensile strength per square inch 1- welding position 3- polarity

Welding position digits: 1- all positions 2- flat and horizontal positions 3- not approved number 4- vertical only

Polarity digits: 0- If 0, refer to previous digit 1- AC or DC reverse or straight 2- AC or DC straight 3- AC or DC straight or reverse 4- AC or DC straight or reverse 5- DC reverse 6- AC or DC reverse 7- AC or DC 8- AC or DC reverse or straight Digits 5 through 8 are low hydrogen electrodes Most common electrodes: E6011- Fast freeze; good penetration. Marginal appearance E6013- Fill freeze; marginal penetration, smooth appearance E7018- Low hydrogen- stronger in tensile strength than mild steel

Electrode Characteristics

Electrode Characteristics continued

Electrode coatings (flux): Synthetic Iron powder Alloys Flux purpose: Produces gaseous shield (keeps out oxygen and nitrogen) Cleanses weld (slag floats to the surface) Slows cooling rate for increased weld strength (slap) Directs and stabilizes arc (barreling effect) Adds strength to the weld (alloying elements.)

Electrode Sizes: 1/16 3/32 1/8 5/32 3/16 of an inch in diameter

Approximate Amperage Settings

Fundamentals of arc welding: Amperage: dependent on mental thickness Arc length: equal to the diameter of the bare end of the electrode Angle of the electrode: 15-25 degrees in the direction of travel. Rate (Speed) of travel: bead width should equal 2 ½ times the diameter of the bare end of the electrode.

Arc Welding hints: (procedure) Methods of striking an arc: scratching tapping Starting a bead- long arc (more heat) Finishing a bead: shorten arc then stop completely and let eye cool for one or two seconds and deposit a spot of weld directly in the crater (to fill it up) Starting a new rod in the middle of the bead: Strike arc one inch ahead of crater. Move back into crater with long arc and proceed to weld as usual.

Arc Length

Electrode Angles

Travel Speed

Starting The Arc

Bead Initiation

Techniques Stringer Weave Beads Narrow and No Motion D. Box Weave A. Circles B. Crescent C. zig zag E. Double J

Bead Formation

Bead Termination

Restarting Interrupted Bead 1. Strike Arc Here 2. Move Electrode to Crown of Crater 3. Resume Travel Forward

Sample Beads For Quality Welding

Trouble Shooting: Undercut: a. too long of arc b. excessive amperage Overlap: a. too low amperage Narrow bead: low amperage too fast rate of travel Wide bead: too slow rate of travel excessive amperage Splatter: a. long arc b. excessive amperage Electrode Sticks: a. too short of an arc b. too low amperage

Methods of identifying metals: Surface appearance Sound Spark test high carbon: many short sparks low carbon: longer shaft like appendages

Controlling distortion: Distortion: forces of expansion and contraction pushing and pulling in metal being welded until it will not return to its original shape or position. Control methods: proper preparation tacking clamping avoid excessive amperage intermittent welding don’t over weld peening use fewer passes back step method weld down hill (sheet metal)

Safety Rules For ARC Welding Secure services of a competent electrician when making electrical installations for an arc-welding machine. Inspect primary and secondary cables regularly. Repair or replace defective cable at one and use only parts that are rated for the welder. Do not run machinery over or under cables. Stand on a dry board while welding if the ground or floor is wet. Make sure that all electrical connections including the power line, arc welding machine cable, electrode and ground clamp are firmly attached before beginning to weld. Wear good quality gauntlet leather gloves. Use electrode holders, which are fully insulated. Protect face and eyes from flying particles of slag by wearing safety glasses, and placing your hand in front of your face to deflect particles when chipping the bead. Wear high top leather shoes to protect feet and ankles from burns caused by weld spatter.

Safety Rules For ARC Welding Wear skullcaps under helmet to protect head from particles or spatter. Keep buttoned parts of clothing such as collar, shirtsleeves, and pockets. Have cuffs of pants turned down in order to avoid catching weld spatter. Avoid wearing ragged clothes while welding. Avoid handling hot metal. Twist electrode free or remove holder, before removing your helmet, if electrode should “freeze” in welding. Do not strike the arc without first covering the face and eyes with the protective shield or helmet. Give the word “cover” to all people standing nearby when ready to strike an arc. Do not weld around small children, as they tend to look directly at the arc. Examine the head shield or helmet and color lens, making sure that there are no cracks, which will permit leakage of light rays.

Safety Rules For ARC Welding Wear protective clothing when welding, and keep all parts of the body covered. The arc flash will penetrate lightweight clothing such as T-shirts. Treat eyes with butyn preparation to prevent inflammation, in case a direct flash is received from the arc at close range. (Also milk, potato water, cool boric acid, or 5% argyrols solution). Keep shop well ventilated when welding steel or cast iron in order to insure comfort of welding operator. Use ventilating fan, or work in the open when welding metals containing zinc lead (galvanized metals). Use forced ventilation when welding in a confined area such as a tank. Drink sweet milk to over come nausea resulting from welding where zinc-oxide fumes are present. Clean the shop frequently, especially in areas where welding is done. (Fire hazard) Never weld where uncovered containers holding combustible or flammable materials are in the shop. The best first aid for minor burns is to immerse the injured area in cold water for several minutes.