Description - · Web viewAn Arc Welder welds together metal components of products as...

Description

An Arc Welder welds together metal components of products as specified by layout, blueprints, diagram,

work order, welding procedures, or oral instructions, using electric arc-welding equipment. They may work on

products such as pipelines, automobiles, boilers, ships, aircraft, and mobile homes.

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Duties Include:

· Connecting cables from welding unit to obtain amperage and voltage

· Examining weld for bead size and other specifications

· Manually guiding electrode or gun along weld line

· Obtaining electrode and inserting electrode into holder

· Striking arc which generates heat to melt and deposit metal from electrode to workpiece and join

edges of workpiece

· Welding in flat, horizontal, vertical, or overhead position

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Working Conditions

Where Do They Work?

· Welders work in manufacturing plants, industries, construction sites, utility installations, repair

shops, or construction companies.

· Two-thirds of all welders are employed in manufacturing plants that produce motor vehicles, ships,

boilers, machinery, appliances, and other metal products.

· One third of all welders work for repair shops or construction companies that build bridges, large

buildings, pipelines, and similar metal structures.

· Depending on the work site, welders may spend their day inside, outside, or in confined spaces such as

tunnels, or inside a large storage tank.

When Do They Work?

· Most work a typical 40 hour week.

· Those on maintenance crews or on a job to meet a deadline may work overtime, holidays, weekends,

or evenings to meet deadlines.

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What Do They Work With?

· Safety gear such as goggles, helmets, protective clothing, safety shoes, and other gear to prevent burns

and injuries.

· Metals that may give off toxic fumes when heated, harmful substances, explosives, and electrical

equipment.

· Welding can be very hot work, especially when working outside during the summer.

· Welding can be very dangerous if safety rules are not followed.

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Training

There are 3 main ways to get the training needed to become a welder:

Formal Training Welder Program

· A high school diploma or GED is required to enter formal welding training programs.

· These programs are offered through community colleges, technical institutes, trade schools, and

in the armed forces.

On the Job Training Program

· Usually lasts from several days or weeks to 1 to 3 years depending on the skill level required for

the job.

· Trainees begin as helpers to experienced workers and are given more challenging work as time

progresses.

· Trainees also receive formal classroom instruction on the technical aspects of welding.

Apprenticeship Training program

· Teaches a range of metalworking skills including the basics of welding.

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Classes that may be helpful to take while in high school include:

· Co-op Education

· Drawing and Design

· Electricity & Electronics

· Industrial Arts

· Machine Shop

· Mechanical Drawing

· Metal Shop

· Shop Math

· Shop Mechanics

· Welding

Helpful Skills and Attributes Include:

· Workers who can bend, stoop, and work in awkward positions

· Manual dexterity, good eye-hand coordination, and good eyesight

· Patience and the ability to concentrate for extended periods of time on a task

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Employment Projections and Salary

The average salary for Arc Welders in the State of Virginia was $28,340 in 2002. The need for welders is

expected to grow 8% throughout the year 2008 nationally and in the State of Virginia.

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Now that you have been presented a few facts about a career in welding, do you think that you would be

interested in becoming a welder?

Take the Interest Checksheet from your clipboard and check Question #1:

_____Yes I would, _____Maybe, or _____No, I would not,

then call your evaluator

(Observation Point #1)

This information was obtained from 2002 Virginia VIEW. Www.vaview.vt.edu.

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You will begin by watching a Welding Safety video. After you watch the video, you will be given a Welding

Safety Test. Safety is very important during this work sample. Serious injury can result if safety rules are not

followed.

Call your evaluator to watch the video and take the safety test.


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Arc Welding has become an important part of manufacturing, construction, and maintenance industries.

Because of this, the number of good arc welders needed in these areas is increasing yearly.

In order for you to learn to arc weld properly, you must repeat the required tasks until you can do them

accurately and consistently. In this section of the work sample you will be given the chance to try some of these

tasks. You will be able to see what an arc welder actually does and how you compare to others who have interest

in this field but haven’t received the specific training that a person would receive in an entry level position in arc

welding.

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In order for you to complete this section of the work sample, you will need to closely listen to the

instructions. If you have any questions at any time, ask your evaluator right away. BE SURE THAT YOU

FOLLOW THE DIRECTIONS AND PAY CLOSE ATTENTION TO SAFETY PRECAUTIONS. If you have

any questions at this time, ask your evaluator. If not, you may continue.


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PREPARING TO WELD-SAFETY RULES

In order to arc weld, the first thing you must learn and remember are the safety rules which apply to this

task. You must know these in order to protect you, your evaluator, and others in the work area.

Follow these directions in order to prepare yourself to weld:

1. Roll down all cuffs and shirt sleeves.

2. Place pant cuffs on the outside of your boots.

3. Button all shirt buttons including the top collar button.

4. If you have matches or lighters in your pockets please remove them, they could ignite.

5.6. Put on a pair of safety glasses and remember not to remove them until you have completed the work

sample.

6. Put on a leather coat and shoe protectors.

7. Adjust a head shield for fit and place it on your head in the “up” position.

8. Obtain a pair of leather gloves and keep them handy. You will need them for picking up hot material,

and while doing the welding exercises.

9. Obtain a pair of pliers and chipping hammer.

Perform the tasks and call your evaluator. (Observation Point #4)

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You must check the work area to make certain that it is safe.

Check the area for the following:

1. Make sure that the arc welding machine is turned off. Locate the “power switch” and see if the switch

is in the “off” position.

2. Check cables to see if there are any breaks or if they are loose where they enter the welding machine.

Also, make certain that you won’t trip on them while welding.

3. Check to see if there are any materials which will burn in the area. If there are, move them to a safe

place so that there will be no chance of fire.

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4. Make certain that there is no water on the floor or on the work bench. If there is, make certain that

you wipe it completely dry so that you won’t receive a shock.

5. Check to see that all persons, including your evaluator, are properly clothed in safety equipment. If

they are not, tell them that you will be welding, and that they should be wearing the proper safety

equipment if they will be observing you.

6. Check to be sure that the electrode cable is plugged into the negative plug at the bottom left-hand

corner of the welder.

Do the tasks and call your evaluator.


REMEMBER NOT TO LOOK DIRECTLY INTO THE ARC WITHOUT USING THE TINTED

SHIELD IN THE WELDING HELMET. DON’T STRIKE AN ARC BEFORE MAKING CERTAIN THAT

ALL PERSONS HAVE THEIR WELDING SHIELD IN PLACE.

ABOVE ALL ELSE, REMEMBER TO LOOK OUT FOR SAFETY HAZARDS WHICH MAY CAUSE

BURNS, EYE INJURY, FIRE, AND SHOCK.

You are now ready to begin the welding practice exercises. Follow these instructions in order, but don’t go

too quickly so that you make mistakes.

PREPARING TO WELD-MATERIAL

Obtain the following materials from your evaluator, placing them on the work bench in order, from left to

right.

1. Three (3) steel plates from the storage bin.

2. Five (5) electrodes from the box beneath the work bench.

3. Welding fixture from the left-hand side of the work bench.

4. Ground clamp and electrode holder which are hanging above the welding machine.

5. Chipping hammer and wire brush tool.

6. Pliers

These materials will look like this when you have completed this section of instructions.

WELDING PRACTICE EXERCISES.

Clean off the welding fixture as best as you can, using the chipping hammer and wire brush tool. Attach

the ground clamp firmly to the welding fixture. Place (1) steel plate on the welding fixture as shown below. Push

all remaining loose materials to the right side of the work bench.



Insert (1) electrode into the electrode holder with the bare wire end in the clamp. Turn the electrode 1/4

turn in order to be certain that the wire is in contact with the clamp.

Set the electrode holder aside. Make certain that no part touches any metal surface.



Go to the welding machine. Turn the “amperage setting dial” to between 90 and 05 amperes. Put the

“power switch” to the “on” position. The welding machine is now in operation. Be certain that the ground

clamp and electrode holder do not come in contact with metal surfaces and cause an arc. It could damage your

eyes. Return to the work bench and put on the leather gloves.



In order to weld correctly, you must be able to maintain the correct welding position, know how to properly

strike an arc, maintain the correct arc length, and move at the correct speed.

CORRECT WELDING POSITION

To place yourself in the correct welding position, follow these directions if you are right handed, if you are

left handed, reverse positions of your hands. Always, if possible, weld directly across, in front of you, either left

to right or right to left.

1. Hold the electrode holder in your right hand.

2. Touch the left hand to the underside of the right hand.

3. Put the left elbow into your left side and your right elbow into your right side.

4. Hold the rod at a 5 to 10 position.

When you are in the correct position, you will look like this:



ALWAYS REMEMBER TO WELD WITH TWO HANDS WHENEVER POSSIBLE.

By using this position, you should be able to hold the electrode steady and control it better.

When you begin to move, always move from left to right, if possible, holding the electrode at a slight angle

(5to 10) as shown in the diagram.

STRIKING THE ARC

Lower your head shield and tell your evaluator to cover up. Remember to do this whenever you are going

to start a weld or strike an arc.

Place yourself in the correct welding position which you have just learned. Place the electrode tip about 3

to 4 inches above the welding fixture surface.

Slowly tap the electrode on the welding fixture surface until an arc is established. Then, raise the tip

immediately to a height of about 1/8 inch, otherwise the electrode will stick to the surface. Lift the electrode to

the height of 3 to 4 inches above the surface in order to break the arc. Repeat this procedure until you can strike

10 consecutive arcs without the electrode sticking to the surface of the fixture. After you can do this go on to the

next step.



Another way of striking an arc is by the scratching method. This method is similar to striking a match.

Lower your head shield and assume the correct welding position. Scratch the electrode slowly over the metal,

and you will see some sparks begin to fly. While you are scratching, raise the electrode tip to about 1/8 inch

above the surface, once you have established the arc.

Remember to keep moving once the arc is established, otherwise it will stick to the surface. Also, don’t jab

the electrode into the plate, because either the electrode will stick or the arc will be broken right away. Repeat

this procedure until you can do it properly 10 times in a row.



CORRECT ARC LENGTH

The arc length is the distance from the tip of the electrode tip to the surface of the metal plate.

Once you have established an arc, maintaining a correct arc length becomes most important. The arc

should be short, about 1/16 to 1/8 inch long. As the electrode burns off, the electrode must be fed into the work

to maintain the correct arc length.

The easiest way to tell if the arc is the correct length, is by listening to the sound. If the arc sounds like

crackling, like eggs frying in a pan, the correct arc length has been established. If too short or too long, you will

either hear a popping or a hissing sound.

CORRECT WELDING SPEED

Another important thing to watch while welding is the puddle of molten metal right behind the arc. DO

NOT WATCH THE ARC ITSELF.

It is the looks of the puddle and the ridge where the molten puddle becomes solid that tells you if you are

traveling at the correct speed. The ridge should be about 3/8 inch behind the electrode. Most beginners tend to

weld too fast, resulting in a thin, uneven looking bead. They are not watching the molten metal.

In order for you to become able to do all four of these operations at the same time and correctly, you will

now practice making a pad. A pad is a series of beads that are run next to each other.

On the plate in front of you, run 10 beads from left to right. (Reverse if you are left-handed). After each

bead has been run, break the arc and raise your head shield. Inspect the bead by comparing it to examples on

the sample board, which is located behind the welding machine. After you run a bead, you will need to cool the

metal. Pick up the metal with the pliers and dunk it into the water. Be sure to have your safety glasses on.

Because of the steam that will come off of the water, be careful not to have your face close to the water.

MAKE CERTAIN THAT YOU REMEMBER TO FOLLOW ALL SAFETY RULES. If your electrode

becomes too short for you to use (minimum of 3 inches), discard it into the coffee can in the back right corner of

the welding booth. Place another of the electrodes into the electrode holder and continue.

Be sure that you assume the correct arc welding position, strike an arc correctly, maintain the correct arc

length, and move at the correct speed. Practice these tasks in order and very slowly so that you will learn the

proper way to arc weld.

After you have completed the pad, it should look like this:

CLEANING THE WELD

After you complete each weld bead, you must clean it properly so that no excess slag or other particles

become imbedded in the weld. Pick up the chipping hammer-wire brush tool. Make certain that you are

wearing your safety glasses. DO NOT PICK UP THE PLATE WITHOUT USING THE PLIERS AND

WEARING YOUR GLOVES-IT IS VERY HOT! Then hit the weld as shown in the diagram, and follow by

scrubbing with the wire brush. Do this until the weld bead is very shiny and clean. Then you can continue by

making another weld bead as you were instructed.

Chipping

Brushing

Remember, you will run a bead, clean the weld and then cool the metal in the water.



FLAT POSITION WELDING

You should know how to perform basic welding techniques of starting the arc and holding it properly. Now

it will be necessary for you to learn how to make two basic welds that are widely used. These welds are the butt

weld and the fillet weld.

BUTT WELDS

The most widely used weld is the butt weld. Place one of the steel plates that you have on the work bench,

next to the one with the pad you just made. Leave about 1/16 to 1/8 inch between the two pieces, so that the weld

will penetrate deep enough into the metal. Tack the plates at both ends by making a short weld bead, so that the

heat will not cause the plates to move apart.

Tack Weld

Now weld the top plates together. Weld from left to right (reverse if left-handed.) Point the electrode down

in the crack between the two plates, keeping the electrode slightly tilted in the direction of travel.

Watch the molten pool of metal to be sure that it distributes itself evenly on both edges and in-between the

plates. After you have completed this weld, compare it to the example on the sample board, then continue on to

the next task.



FILLET WELD

Another weld which is widely used, because it is used in corners, is the fillet weld.

When making fillet welds, it is important to hold the electrode in a 45-degree angle between the two sides,

or the metal will not distribute itself evenly. To make it easy to get the 45-degree angle, it is best to put the

electrode in the holder at a 45-degree angle.

Position the electrode in the holder properly, then obtain the third metal plate. Assemble the third metal

plate to the second plate as shown, at a 90-degree angle to it.

While holding the plate with your left hand (your right hand if you are left-handed), tack the two ends of

the upright metal plate to the bottom plate. Then perform the weld on the side closest to you by moving from left

to right (reverse if left-handed), with the electrode at a 35to 40-degree angle. After you have done this, stop and

compare it against the example on the sample board. The height and width of the weld bead should be equal.



Turn the assembly around and make another fillet weld on the other side of the two plates, try to improve

on your last attempt at this weld. REMEMBER TO CLEAN THE WELDS AFTER YOU FINISH RUNNING A

BEAD.

After you have completed this task, turn off the welding machine and hand the electrode holder down on

the work bench.



Replace all the materials and equipment which you have used to their positions which are labeled. Sweep

the area and pick up all waste materials. BE CAREFUL THAT YOU DON’T GET BURNED ON ANY OF THE

HOT METAL PLATES. Throw the waste in proper receptacles. Get the broom and dust pan. Clean the work

table and throw the waste into the metal trash can. Take your Interest Check Sheet and answer question #2.

Now that you have completed the work sample, would you like to do that type of work for a living?

Check:

_____ No, I wouldn’t _____ Maybe

_____ Yes, I would

Answer the question and call your evaluator.


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