The Motor Skills of Welding
Achieving Excellence
by Eric Waterfield
The suggested light set-up pictured above is much brighter and is a great help, working well in dark areas. Of course, even brighter lights would be better suited, and when I find one that will come closer to the arc light in brilliance that will fit the bill, I may buy it.
The obvious down side to this suggestion is spatter (common to SMA or GMA welding) attaching to the lens of the light source. This problem may be resolved if a protective and changeable clear cover lens is provided. However, this problem may be seen as too much of a stumbling block to be useful for these processes, but its most practical purpose at the moment may be for GTAW because of the inherent absence of spatter.
- Auto Darkening Lenses
Auto darkening lenses serve a very useful purpose; they allow the welder to position the electrode exactly where the arc is intended to be struck. Although a bright light source may replace the need for an auto darkening, expensive face mask, it could also ad to its usefulness. Such face masks implement an electronic lens that provides an instant reduction in the light the moment an arc is struck. This happens so fast that the eye does not register the glare of the arc. The problem is that the eye is still not prepared for the high contrast behind the face mask. A strong fill in light will "reduce" the need for the eye to adjust as the suggested light reduces the contrast by filling in the shadows and providing more overall illumination.
- Dark Safety Glasses… improve a welder's vision
Another important situation often overlooked is when the eye is exposed to a bright light such as when working in bright sunlight the opening of iris is reduced to compensate.
As the pupil becomes smaller its light-gathering ability is reduced, and when the light is suddenly and drastically reduced as it is behind a welding mask, one is almost blind for a time until the eye adjusts. Even with a fill in light, it is still difficult to see ones work until the pupils expand enough to gather more light to allow the eyes to become adjusted.
The wearing of safety glasses is always recommended in an industrial area, wearing dark safety glasses is not only a good idea to protect one's eyes from particles, or from other welder's arc rays. The tinted lenses will reduce the amount that the iris closes in a brightly lit area making the available light to the welders eyes appear more of an even density, thus it will be easier for the eyes to more quickly adapt to the sudden dark environment as the welder dons a face shield.
It is possible to combine properly filtered lenses, so that if the welder is wearing shade numbered safety glasses, then the density of the lens in the face shield may be reduced accordingly to perhaps from #11 or #10 to #9 or #8. An added convenience is not having to remove the glasses each time a weld is performed, and maintaining the eyes stability by reducing the amount that the iris needs to expand behind a face shield. It is also possible that eye strain is reduced as a result.
A clear lens placed in front of the filter lens is often overlooked by a welder until it is "clear" that he can't see. Glass lenses being so easily covered with spatter make me wonder why they are in use. Very often an instructor reminds a student to change the clear lens in his face shield. Some times the "Glass" lens is so crusted over with spatter, it is a wonder that he can see at all
Plastic cover lenses resist spatter and will outlast a glass lens many times over, the down side is that a plastic lens will scratch easily, but will still be serviceable for quite some time, providing it is only the one on the outside of the mask that is damaged. A plain lens used on the inside of the mask with only a small amount of scratching and fogging will have a much more detrimental effect, and should be replaced often. But it will still provide serviceable use on the outside of the mask, and the new clear lens placed on the inside.
- Smoke
Visibility when welding in the overhead position is also compromised by the smoke from processes such as stick welding where a flux is used, especially when welding on a flat horizontal plate where the smoke tends to hang and build up. A round surface such as a pipe allows the fumes to dissipate more freely due to the rising hot gasses. Likewise, if a plate can be tilted, even slightly, it will improve the visibility by allowing the smoke to escape. Welding in a vertical position seldom has problems with visibility due to smoke, this is because the heated air rising up lifts the fumes away from the weld area immediately as they form.
PART TWO:TOUCH
A well-developed sense of touch is a very important part of the skill development in welding. It is often thought that the electrode must be held at a certain distance from the base metal. However, some manipulation involving contact of the SMAW electrode to the base metal will usually be required to control and deposit the weld metal correctly in any position, weather it is flat, vertical, horizontal or overhead. This skill will require a very sensitive and well-trained hand that requires much dedicated practice to acquire. The flux on certain electrodes allow for contact with the base metal by forming a cup shaped recess where the core wire is melted back for a short distance, this feature has functions that include maintaining a correct or minimum arc length. However, If the downward pressure applied to the electrode during contact welding is too great, the flux will be broken off causing unresolved flux to degas and be included in the weld deposit, possibly as inclusions of slag or porosity. This is especially true of low hydrogen electrodes such as E7018. These are all position electrodes and require finely controlled manipulation where a fine sense of touch is required, especially when welding out of position..
Some stick electrodes are very forgiving and easy to use especially in the flat position, and perhaps in a shallow groove. These are the heavily coated iron powder electrodes that are contact electrodes.
Another class of electrode that requires the most energetic manipulation are the organic coated electrodes such as the Exx10 or Exx11, this type of electrode produces a shielding gas in addition to a slag cover. This class of electrode requires some arc length to be able to develop a cloud of shielding gas, but it will still require some contact with the base metal. The root pass on pipe in the five G position may be applied either up hill or down hill, but in either case the electrode will be in close contact with the base metal, this is often with either a drag, or a stepping movement where the electrode intermittently makes contact with the base metal. Constant contact is most often applied in welding the downhill root pass on a pipe where carefully controlled constant pressure is applied to the electrode in order to obtain a fully penetrated and acceptable root bead.
- Rhythm
Welding is an art form where appearance matters. An experienced welder will look at a weld and will judge it by its aesthetics. The appearance of a weld is often an indication of the welder's skill, or lack of it.
A constantly repeated pattern on a weld deposit enhances its appearance and If rhythm is not used in say a vertical weld, the pattern will keep changing, this will result in a weld where the least problem will be a weld less pleasing to the eye.
Rhythm is a sense that really belongs with all the senses. On a job site one frequently hears a welder quietly singing or humming a tune as he works, perhaps not realizing that the timing of the music is really a subconscious aid to making a presentable weld by providing the timing of the electrode movement.
Weaving or stepping a weld deposit. The rhythm of a tune helps with the repetitive movement to aid the control the quality and appearance " pattern" of the weld deposit, in much the same way as the music for a dance dictates the movement and steppes of the dancer.
Perhaps there are welders who are not musically inclined, but there is no doubt that even without this aid, the person must have a sense of rhythm and the ability to time and space the movements in the same way, but a graceful waltz is difficult to perform without ¾ time.
- An analogy
Imagine an electrode is a tube and from this tube a viscous liquid is being emitted, the fluid being the molten metal. Now imagine that you are applying the liquid to a flat surface and you are creating a pattern. It could be something like using a hot glue gun or placing icing on a birthday cake with an icing gun.
This type of electrode forms a cup in the flux at the end of the rod, to maintain the correct distance of the core wire from the base metal when it is rested at the correct angle gently on the plate. Once the arc is struck with this electrode and the amperage is properly adjusted, it is simply a matter of maintaining the correct rod angle and allowing the melt off rate to govern the travel speed.
Touch is readily appreciated when the student realizes that he can feel when the electrode is touching the plate coupled with what he sees and hears when the arc length will vary as the electrode is allowed to move away from or closer to the work. The sensitivity involved with the feel of the electrode making contact with the parent metal.
PART THREE: SOUND
The sound of the arc can inform a welder about its condition - for example, the type of electricity, AC or DC positive or negative.
- Polarity
An SMAW electrode will have a specific sound when it is coupled to the negative pole that can be very different from the sound made when it is connected to the positive pole. An E6010 electrode is a very good example, with an unmistakeable sound; in fact, if the polarity is in doubt, any skilled experienced welder will recognize the difference immediately.
Alternating current also has a very distinctive sound.
- Electrode Type
What type of electrode is being used, 'organic' or 'inorganic'?
- Penetration
Penetration of the root, especially in pipe welding, has a very distinctive sound.
Other information gathered by ones hearing will soon become evident as a welders experience and skills advance. There are in fact times when being able to decipher the sounds coming from the arc action will be crucial in adjusting the required parameters in SMAW, as it will for several other welding arc processes. The operator of Electro slag welding depends upon emitted sounds related to the arc action and its condition, sounds that are unmistakable to the experienced operator.
The sounds from submerged arc welding, a predecessor and close relation to ESW, will also impart information about the current conditions in the weld action.
The sounds of GMA welding are especially informative. Volt-Amp settings are balanced by the sound i.e. wire speed too fast, volts too high. One can hear right or wrong polarity setting on this process, it is most obvious.
Being aware of the sounds made by the different situations is learned by taking the time to listen to the arc during welding and realizing what sounds the different settings make, and remembering them.
A student may be surprised when an instructor recognizes the state of the arc simply by the sound, but this is a result of much experience and observation.
Finally… addressing the weld
Perhaps the most important difficulty in addressing the weld is being able to relax. Concentration on technique is important, but early in ones practice even an experienced welder when faced with a new process will often be so focussed he does not realize how tense he has become. Ask any TIG welder to recall his early attempts to "walk the cup" whilst welding pipe.
Practice takes time, but most important is the acceptance of the fact that things do not always turn out right on the first attempts. Allowing for these learning experiences to happen knowing that eventually the sub conscious (I refer to it as the guy in the back room) will eventually take over. When this happens, it suddenly (not gradually) seems that you are just a spectator and you are simply watching it happen. At this point you realize that, "HEY I'm relaxed" and "Why did I ever think that this was difficult?", and you have arrived...
Comfort is not the only consideration when one is preparing to weld although it is very important, because if the operator adopts an awkward stance, he will not be able to relax and perform to the best of his ability. There is no such thing as cheating when it comes to positioning ones self to make a weld and especially when weld quality is paramount. Leaning against a solid object or sitting down if it is possible helps to steady ones body and improve ones hand control.
Most people are not ambidextrous, but the ability to weld using either hand will prove to be a great advantage down the road. This practice may be best left until proficiency has been achieved with one's dominant hand.
Make no mistakes…? No! Do things wrong deliberately! But only at welding school…
Experience is made up of events that turn out right and perhaps more so of the things that turn out wrong.
There is an old truism that says, "no one is a failure until he/she gives up trying".
(On a personal note… sure, there were times when I didn't make it and was disappointed when I didn't get the job, but knowing where my skills were lacking allowed me to address them. With the help of my mentors, I was that much stronger to pass the next test and get a better position.)
The advice I gave myself is to never turn down the chance to take a test for, in my opinion, one failed test is worth ten lessons.
When a person turns down a test, one has truly failed and, worst of all, the judge is one's self.
We may be told what polarity to use, how many amps and volts, rod angle, arc length and travel speed etc. So if you are an automaton you do these things and perhaps get good results and a pat on the back. Fortunately we are not automatons or morons and in the real world we must follow procedural instructions provided on many job sites. And we must most often make our own decisions. It is not only a matter of knowing what works, one must also know what does not work, and although we are told that one way is good and the other is bad the best way to find that out is to create a situation deliberately.
For example: We are told that an electrode must be connected to a specific polarity, so try the so-called wrong polarity. What happens to an E6010 if it is connected to the negative pole? We read that an E7018 must be connected to the Positive pole, but are there any exceptions?. An E7024 is said to operate on any polarity including AC, true, but what polarity does it work on best? There are electrodes that are designed to operate in certain positions i.e. flat or vertical-up or down. Try to weld with an E7018 vertically down. Or with an E7024 vertical up or down. Some of the results may surprise you. There are many other examples with all processes that unless they are first experienced can be a cause of embarrassment if they happen in the real world such as on a job site. Ignorance could on some jobs be expensive, or even a source of danger if the problem is not discovered, but never lose sight that although there are many exceptions to the rule, be very careful if you decide to even bend them.
Eric Waterfield
Introduction
I do not know of any motor skill taught effectively by correspondence, especially and in particular, welding.
So the following is in no way an attempt to teach a student of welding how to weld - only a competent welding instructor can do that. Welding instructors in the institutions here in Canada are knowledgeable enough and possess the skills required to teach all the welding processes commonly used in industry today.
We may explain skill development as experience gained through repeated practice. This is true, but in my opinion the results of practice may be speeded up by the early recognition of the role the senses play. Eventually they will fade into the recesses of the subconscious mind and become such an automatic response that one forgets that they are there.
I have been a welder and a welding instructor for many years and, like all instructors, I will be asked by students, "How do I do this?" I have to be truthful and say, "Give me the stinger and we will both find out."
This leads me to realize the importance of early recognition of the physical senses that are in play as a student creates a weld.
Perhaps the person who is highly skilled and has a long experience in welding takes for granted, and is no longer aware of, the feedback from the sight, sounds and feel of his actions as he creates a weld, until he is deprived of any one of them.
Three wise monkeys…See all. Feel all. Hear all.
First monkey 'See All' - sight
All students of welding begin to practice by relying on sight to guide them in their efforts to create an acceptable weld. There is no doubt that the sense of sight provides the most important information feedback of all the senses, for if one can't see what one is doing, it is near impossible to make a weld. However, sight is not the only sense essential to all successful welders.
Second monkey 'Feel All' - touch
The importance of this sense applies to processes such as SMAW, OAW and GTAW more than others, but especially when a student welder strives to gains the skill required to strike an arc and make a fairly good semblance of a weld with SMAW.
Third monkey 'Hear all' - sound
The sounds made by the arc will convey important information about the weld progress and condition, thus allowing for more fine adjustment.
PART ONE: SEE ALL
The instructor adjusts the amperage and explains how to strike an arc, also the importance of the distance of the electrode tip from the plate, the angle of the electrode and the travel speed. He will also explain things like how the slag forms on the end of a used SMAW electrode and how it is important to clean it off before trying to restart the arc. The instructor demonstrates, but first before he strikes an arc, he makes sure that the student has observed all the safety rules, noting that the students mask is in front of his face protecting him from the arc flash.
After this, it is monkey see, monkey "try to do" as the student struggles to reproduce what his instructor made look so ridiculously easy to do. Unfortunately, the first difficulty the eager student has must deal with is almost total blindness behind the facemask.
Improve your arc welding… by making your welding tasks more visible
Whilst welding in a brightly lit area the surrounding light can be a help if it comes from the right direction; it can also be a hindrance if its origin is in the wrong direction. Most light comes from above, be it from the sun, or shop light. Most welders find that welding with the plate on the flat downward position is the easiest as gravity is a great help, but mostly it is because this position generally allows the available light to fill in the shadows, making it easier to see. However, light coming from behind a welder may enter the face mask where the reflection from the welding lens will diminish his ability to see the weld area through it. Light-colored clothing may reflect the light from the arc back into the face shield and have the same effect. Providing a means for blocking the light from entering the face shield is very helpful.
Welding in the overhead position presents the most difficulty because the welder is not only now dealing with the force of gravity; it is generally difficult to see because the shop light or sunlight is shining from above and behind the fixture. This situation will put the weld area in deep shadow in contrast with the surrounding light; an added fill-in light to illuminate the dark areas would be very helpful.
- Reduce the shadows
Arc welding produces a lot of light, but in spite of this, welders often find it difficult to see well enough to place the weld where it is supposed to be. The reason for this is that light rays are directional, i.e. stream directly away from the weld area creating dark shadows in high contrast, whilst the arc is so bright that in spite of the filter lens in the welding screen, it dazzles the welder and deepens the dark shadows surrounding the weld area. This causes the operator to lose most of his ability to direct the progression of the weld deposit.
Most welders find that a fill-in light is helpful, and will often use a trouble light (a light bulb at the end of an electric cable), but this is most often a challenge in setup and placement so that the light is directed where it is most effective. The setup can be cumbersome, and sparks have the annoying habit of destroying the light bulb. I have often thought that if a welding helmet with a built-in fill light with sufficient intensity to effectively reduce the shadows was available it would be a good asset to the welder, and so I decided to try and prove my idea.
To the right is a picture of one of the crude light set-ups that I used, and I don't doubt that if this idea catches on, a more sophisticated arrangement will be developed, probably using a more powerful light source.
I found some inexpensive LED flash lights that, when strapped to my head shield, provided a very helpful fill in light. They helped to reduce the dark shadows sufficiently to improve my vision of the weld area and allowed me to direct the arc better. These flashlights are bright, and of a conveniently small shape.
Although there are brighter lights available, I have not yet found any that were as simple or convenient enough to fit to my welding helmet as easily. However I found a small twelve-volt auto flood light that was much brighter and more effective, but it required a separate power source. This was solved by using a small twelve volt battery intended for an electric trailer braking system; it measured three by four by four inches, and can be carried on ones belt held in a small pouch. A well-insulated cable from the battery runs to the light mounted on the face mask.
The user should be aware that there may be some unforeseen risk involved with this arrangement but this is for the user to assume. The main risks are probably from possible burns if an electrical short should happen to overheat the cable. A fuse or a breaker should be built in for safety. Also a break in a conductor could cause an arc that could possibly result in a burn so it is imperative to use a good flexible cable in good condition.
Although this involves low voltages, there are circumstances where the danger of electrocution or a very unpleasant electric shock is a possibility especially in wet conditions.
(I have had a personal experience of receiving a surprisingly strong electric shock from a twelve volt battery. I was sitting in an aluminum boat attaching cables to a bilge pump at a time when I was very wet with sea water…)