Metals 1 and 2 Model

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Lesson Plan Industry Sector
Manufacturing & Product Development

Lesson Plan Originally Created By: Gregg Bridges

Striking an Arc / Maintaining an Arc

Part of Unit: Arc Welding Processes and Equipment

Lesson Plan Overview / Details

This lesson will teach beginning welding students how to set up theSMAW welding machine, how to strike an arc, how to maintain the arc,and finally various techniques for manipulating the rod to reach thedesired outcome of weld bead.

Lesson Time

One period
55 Minutes

Objectives and Goals

  • Student will demonstrate proper current selection for E6013 welding rod.
  • Student will demonstrate proper voltage selection for E6013 welding rod.
  • Student will demonstrate proper use of the "scratch" and "tap" method for starting the arc.
  • Student will maintain the arc across the length of their practice welding.
  • Student will demonstrate various rod manipulation techniques.

Activities in this Lesson

  • Striking the arc - Demo / Modeling

    After taking roll and sending the students into the welding shop to dress out I gather the 15 students around myself in the middle of the welding shop.  I have a small metal table used for demonstrations in my class.  I check each student to ensure that each has the proper PPE in place.  With the power off on the machine I show the students how to turn the selector knob to AC current.  This is the desired current for E6013 rod.   I then show them  how to turn their voltage selector to 75.  I then show the students how to place the ground clamp on their station and the rod into the stinger. 

    With the power still off I demonstrate the tap technique which is to quickly tap the end of the rod onto your weld metal and quickly remove it.   I then demonstrate the scratch technique which is similar to striking a match.  Be sure to explain to your students that a 1/8 inch gap must be maintained.  Any longer and the arc will go out.  Any shorter and the rod will weld itself to the metal.

    I show my students what to do if thier rod does become welded to the table.  Turn off the power first, then release the rod from the stinger and gently rock it back and forth to release it. 

      I now ask that all students "cover" or place their helmets down.  I scan the group to make sure they are safe.  I then turn on the power and demonstrate the tap technique  and the scratch technique.

     

    I give a quick demo on how to shut off the power on their machine,  use the chipping hammer to chip slag, then using long welding tongs dip their metal into the quench tank. 

  • Tap and Scratch Technique - Lab / Shop

    Now I send each student off to their pre-assigned welding booth.  Each student is given a welding coupon.  This is a piece of mild steel.  1/4 inch thick,  3 inches wide and 6 inches long.  Each student keeps this piece of metal for the semester.  They can lay many layers of weld bead on this one piece of metal.   I also give each student 2 E6013 rods 1/8 diameter to begin with.   I tell the students to just practice getting the rod started.  I want them to take baby steps.  I also tell all the students that welding is like riding a bike.  Some will get it quickly and some will take longer.  It's not how fast they gain the concept but how well.  I poke my head in to each booth.  Welding helmet down of course to check students progress.  I help with hands on instruction to those who are struggling.  I usually do this for about 15 minutes.

  • Maintaining the Arc - Demo / Modeling

    Once 15 minutes has elapsed I gather the group back again around my demo table.  With the power off and helmets up I explain the importance of maintaining the arc.  Once an arc is established the welder must make sure that a 1/8 inch gap is always maintained.  I show the students how the welding rod burns just like a cigarette.  (I haven't found a better analogy yet).  As the rod is being "consumed" you as the welder must be pushing it down towards the metal and keeping it 1/8 gap at all times.    I demonstrate this a few times then again ask that all students cover.

    Check to make sure this is done then turn on your power.  I use the same technique I just taught the students to start the arc then i demonstrate the drag technique.  Hold the welding rod at a consistent 1/8 inch off the metal and simply drag it across the length of the metal.  This is their next task

  • Maintaining the Arc - Lab / Shop

    Again I send the group to their booths.  Now I check to see if they can maintain their arc from one end of their coupon to the other.  Some students will still be struggling with starting an arc.  Encourage them and let them know that there is no need to rush.  Take baby steps and then move on.  I use hands on demonstrations again for those that are struggling.

  • Rod manipulation - Demo / Modeling

    Once another 15 mins has elapsed I gather students a final time to show them various rod manipulation techniques.  The three I start with are circles,  half-moons, and zig zag.  I show each technique with the power off and ask that each student now lay one bead of each.  I never require one technique over another but instead ask the student which they prefer.  This has always resulted in great weld beads and I've yet to see a difference with the techniques in regards to penetration or effectiveness.

  • Rod Manipulation - Lab / Shop

    For the final time of the day I send them again to their booths to demonstrate what I have just shown them.  Again I check on each student in each booth and correct where needed. 

    • SMAW Techniques.ppt [ Download ] This is a power point that explains almost all there is to know about SMAW rod techniques. I suggest using what ever slide you may need.

Assessment

Assessment Types:
Observations,

I assess each student on a student by student basis during this lesson.  I have found it hard to place an end of the period deadline for mastering these techniques.  Instead I encourage each student to keep working on what we have discussed. 

The first assessment is to simply poke your head into their booth while they are trying to start an arc.  A simple pass or fail is used.  Either they can or they can't.  I've found the best way to show the students how to do it correctly is to actually grab their hands and do it with them.


The second assessment is maintaining the arc.  Again either they can or they can't.  I know they can when I witness them start an arc and make one continuous bead across the length of the coupon. Again be encouraging.  You will have some students who get it right away and others that are still struggling with starting the arc.  hands on demonstrations are terrific here as well.

 

Lastly the assessment  is rod manipulation.  Check on each student and see if they are actually moving the rod.  You can tell the difference between the drag technique and any one of the manipulation techniques by the size of the bead.  If they actually manipulated the rod the bead will be flatter and wider.  I ask each student which they preferred and encourage them to stick with that technique.

 

Closing thoughts:  Although this lesson may only take one day the assessment itself may take up to a week or longer.  It all depends on you.  I strongly suggest you start your students with E6013 rod.  It can be ran on any current ( preferrably AC though) and is extremely forgiving.  It is very easy to start and maintain.  You will f ind later as well as your students that other rods are not as forgiving.  Any small mistake and you either kill the arc or your bead looks terrible.