STRESS LEARNING: CHALLENGES BUILD A BETTER WELDER
Making the task tough at the beginning makes it a whole lot easier to tackle industrial jobs

By James E. Greer

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Traditional training and education normally begin with the most simple and basic information and tasks and then progress into more complicated areas. Mathematics is an ideal example. A student first learns the principles of addition and after having mastered that task will move into more complicated calculations such as multiplication and division. In this standard educational model, lessons become progressively harder on a daily basis, every task is challenging, the chance of failure exists within every exercise, and skills are developed very slowly. The result is that students may become frustrated.

A Teaching Alternative Stress learning is an alternative teaching/training approach, and is particularly useful in welding training and education environments. It differs from the conventional teaching method by reversing the order in which information and tasks are learned. Students are taught a difficult, more advanced task first. Easier ones follow. Since welding tasks are often similar, once the most difficult skills are attained, the skills transfer to the similar easier ones. Thus, students have not wasted their time practicing basic or intermediate level skills. It is challenging, but students walk away with a higher degree of skill at a much more rapid rate of attainment. Since many tasks are taught faster, less overall training time is required, which saves training dollars. Students also improve their learning and understanding of basic concepts, improve technique, and obtain greater mastery of the material using this method of training.

Speeds Skill Learning Stress learning can accelerate student learning of basic skills in shielded metal arc welding (SMAW) training by making the student able to control welding variables much faster than if standard teaching methods are used. Stress learning increases the student’s ability to become proficient in striking an arc and mastering the basic SMAW variables of arc length and travel speed. These skills are learned far more rapidly and to a greater proficiency level because of stress learning.

Stress learning also helps in the attainment of theoretical concepts. In the basic shielded metal arc welding class, the students begin their welding practice after ten hours of safety instruction and a lecture on the six basic SMAW fundamentals: type of electrode, size of electrode, current setting, arc length, travel speed, and electrode angle.

At Moraine Valley Community College’s Welding Technology Program, stress learning is used in many ways. Below are a few examples to illustrate this methodology and explain some of its benefits.

Example 1: Bare Electrodes for SMAW Most students have trouble learning to strike an arc when first learning to weld, so it makes no difference to them if they are using an electrode that is extremely difficult to weld with or an easier welding electrode.

Therefore, to teach SMAW, I take a bare gas tungsten arc welding (GTAW) rod, ER70S-6, cut down to 12-in. lengths to use as the electrode. Most students have a great deal of difficulty starting the arc because uncovered or bare electrodes are extremely hard to use. The bare electrode tends to stick to the work when an arc initiation is attempted, making it very difficult.

In order to weld with the bare electrode, the student must first learn to strike an arc like a match. The tapping method does not work very well. The student must do the arc strike correctly or the electrode will stick. A student who becomes proficient in starting the arc with the uncovered electrode has no problem starting an arc with any covered SMAW electrode even when welding at low amperages. This is because mastery of a hard task makes it easier to complete a similar yet easier task.

When using the bare electrode it is also very difficult to maintain the arc while welding. If the arc length becomes too long, the arc will extinguish because there is no ionized gas column to help maintain the arc. If the arc length becomes too short, the electrode will short circuit and weld itself to the base metal. This causes the student to learn to strike the arc correctly, to preheat the material with a long arc before attempting to weld (a non-low-hydrogen start) and to hold a constant arc while welding. These skills can later be applied to standard SMAW electrodes.

Expanding the Learning Opportunities The uncovered electrode provides another instructional opportunity. I demonstrate a weld and then wrap a piece of wet paper towel around the electrode to show how a crude coating was first developed and the change the cellulose makes in the quality of the weld. When the weld is made with the bare electrode, the student can see the oxidized surface in the crater of the weld. Without changing anything except adding the paper towel to the electrode, the students notice it is possible to hold a much tighter arc length and that the weld quality is much better.

This demonstration is used as an introduction to the function of coatings on electrodes and to explain the use of shielding gases in GTAW, GMAW, and other processes that use a shielding medium.

Example 2: Oxyfuel Cutting The Welding Advisory Committee, a group of local industry volunteers who advise the college regarding welding, determined manual oxyfuel cutting should be a program objective. To meet this objective, all the steel used in the shielded metal arc welding classes is cut by hand using the oxyfuel welding process. In order to train to a high proficiency level, it was decided all cutting would be done by the students, so no precut materials are provided. In the basic classes, the students are given square tube, which is difficult to cut and offers the beginner a challenge.

To practice welding T-joints, the student must cut rectangular pieces from the square tube. To achieve good joint fitup, the student must cut straight because no grinding is allowed in the beginning classes. The better the skills used to make the cut, the better the fitup of the resulting joint.

In the advanced classes, students must progress their manual oxyfuel cutting skills to a much higher level. They are required to cut all their own bevels by hand. The students are constantly reminded they are not enrolled in a grinding class and are expected to use a grinder only to clean the bevel face and not to correct bad cuts. In the pipe class, all of the carbon steel pipe welded with SMAW is beveled by hand. This forces the students to again increase their skill level. The students often complain that other schools provide precut material to weld on, but when they join the work force they see their cutting skills are far advanced from those from other schools. The reason is stress learning.

Example 3: Gas Tungsten Arc Welding When doing gas tungsten arc welding training, the students are started on aluminum. For the most part, students enjoy the GTAW process and feel superior in the knowledge many welders are not able to GTA weld. Once they gain proficiency in aluminum, they are introduced to stainless steel welding, where they weld fillets on approximately 0.062-in.-thick T and lap joints. Once proficiency is gained (or at least approached with the 0.062-in. stainless), the real stress learning activity begins.

A Real Test of Skill Gas tungsten arc welding of razor blades is a stress learning technique proven to be very successful. The students attempt to weld razor blades together using a backing gas purge fixture. The razor blades, of course, are very thin, and the backing gas purge fixture does not cool the weld joint as when applying copper to the back of the joint. The blades are placed in the fixture and held in position using a good quality masking tape. The fixture could be used to clamp the blades in place, but that would make it too easy to position the pieces. The backing gas is 100% argon. The tungsten is 1Ž16-in. ceriated tungsten ground to a point. This size tungsten is normally the smallest tungsten commonly found on job sites in the Chicagoland area. The 1Ž16-in. tungsten size makes the students compensate much as if they were welding a thin section in industry. The tungsten used could be smaller so the student is expected to grind the electrode enough to compensate for its original size. The students are not allowed to produce autogenous welds but must add a filler metal.

Bringing Out the Best The blades are difficult to weld, and this project requires many skills on the student’s part. The welding procedure tolerances for successful completion of this project are restrictive, and there is little room for error. The welding current must be set correctly using the remote foot control. If the setting is too high, it will cause melt-through. If it is too low, the penetration will not be achieved. Many students rely on the foot control to set the current. The students are often not too concerned with the panel control current setting because it can be fine-tuned with the remote control. With razor blade welding, the setting must be very close or the project will be doomed from the start. The student is forced to read the heat input by watching the weld pool very closely. Many of the students do not really learn to control heat input closely with GTAW until they attempt this project.

Travel speed is another weld variable that must be very precise to obtain proper penetration and correct bead width. Reading the welding pool is another skill the razor blade project teaches. When the students try welding open butt joints using the GTAW process, they normally have a difficult time recognizing if penetration is acceptable. Once students have mastered the razor blade welding project, they usually are able to successfully judge GTAW penetration on butt joints.

Welding Thin Material Made Easier Starting the arc on the razor blades without melt-through teaches a useful skill for welding thin materials. The razor blade is so much thinner than the average material welded that the student can easily start a weld on material that other welders would have trouble with. Adding filler metal to the weld is a skill instructors sometimes wish their students were more adept at. This stress learning project provides them with that skill. The dip feed technique of filler metal addition is used. If the students do not use this technique almost to perfection, they will fail the project. When they are allowed to weld on other projects, their competency in filler metal addition can be observed. Finishing the weld without melt-through and backing gas pressure are skills that must also be mastered.

Ready to Tackle Real Jobs Students who gain proficiency with this project can be very successful welding the thin material normally found in industry because typical industrial applications are usually much thicker than razor blades. This is an excellent example of how stress learning makes the student more industrially proficient.

The best thing about stress learning is that it reinvigorates the students’ interest by challenging them and making them aware they are progressing and succeeding. It builds confidence while it builds knowledge and skill.

Stress learning, of course, cannot be applied to all training situations, but it is particularly effective for a hands-on skills training environment. Since students are given projects that reflect the skills they will be required to possess and tasks they will be required to perform on the job, this adds to the success of the training.

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JAMES E. GREER (greer@morainevalley.edu) is a professor at Moraine Valley Community College, Palos Hills, Ill., and an AWS Vice President. Paper presented at Third International Conference on Education in Welding, JOM Institute, Helsingør, Denmark.

(INFO FOUND AT:   http://www.aws.org/wj/apr03/feature.html )