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Robert Yates

Welding Fundamentals and Welding 101-01

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Welding Fundamentals and Welding 101-01

WARNING


Never look at the welding arc without protection. Looking at the arc with the naked eye could result in permanent eye damage. If you receive flash burns, medical personnel should treat them.

What is Welding?

Welding is the fusion of two like or dissimilar metals.

Before we discuss the different types of welding machines, you must first have a basic knowledge of the electrical terms used with welding.

Electrical Terms

Many terms are associated with arc welding. The following basic terms are especially important.

ALTERNATING CURRENT. — Alternating current is an electrical current that has alternating negative and positive values. In the first half-cycle, the current flows in one direction and then reverses itself for the next half-cycle. In one complete cycle, the current spends 50 percent of the time flowing one way and the other 50 percent flowing the other way. The rate of change in direction is called frequency, and it is indicated by cycles per second. In the United States, the alternating current is set at 60 cycles per second.

AMPERE.— Amperes, sometimes called “amps,” refers to the amount of current that flows through a circuit. It is measured by an “amp” meter.

CONDUCTOR.— Conductor means any material that allows the passage of an electrical current.

CURRENT.— Current is the movement or flow of an electrical charge through a conductor.

DIRECT CURRENT.— Direct current is an electrical current that flows in one direction only.

ELECTRICAL CIRCUIT.— Electrical circuit is the path taken by an electrical current flowing through a conductor from one terminal of the source to the load and returning to the other terminal of the source.

POLARITY.— Polarity is the direction of the flow of current in a circuit. Since current flows in one direction only in a dc welder, the polarity becomes an important factor in welding operations.

RESISTANCE.— Resistance is the opposition of the conductor to the flow of current. Resistance causes electrical energy to be changed into heat.

VOLT.— A volt is the force required to make the current flow in an electrical circuit. It can be compared to pressure in a hydraulic system. Volts are measured with a voltmeter.
Cables
Welding cables carry the current to and from the work piece. One of the cables runs from the welding machine to the electrode holder and the other cable connects the work piece to the welding machine. The cable that connects the work piece to the welding machine is called the ground. When the machine is turned on and the operator touches the electrode to the work piece, the circuit is completed, current begins to flow, and the welding process commences.
The welding cables must be flexible, durable, well insulated, and large enough to carry the required current. Only cable that is specifically designed for welding should be used. A highly flexible cable must be used for the electrode holder connection. This is necessary so the operator can easily maneuver the electrode holder during the welding process. The ground cable need not beso flexible because once it is connected, it does not move.


Electrode Holder

An electrode holder, commonly called a stinger, is a clamping device for holding the electrode securely in any position. The welding cable attaches to the holder through the hollow insulated handle. The design of the electrode holder permits quick and easy electrode exchange. Two general types of electrode holders are in use: insulated and non-insulated. The non-insulated holders are not recommended because they are subject to accidental short-circuiting if bumped against the work piece during welding. For safety reasons, try to ensure the use of only insulated stingers on the jobsite.

Electrode holders are made in different sizes, and manufacturers have their own system of designation. Each holder is designed for use within a specified range of electrode diameters and welding current. You require a larger holder when welding with a machine having a 300-ampere rating than when welding with a 100-ampere machine. If the holder is too small, it will overheat.


Ground Clamps

The use of a good ground clamp is essential to producing quality welds. Without proper grounding, the circuit voltage fails to produce enough heat for proper welding, and there is the possibility of damage to the welding machine and cables. Three basic methods are used to ground a welding machine. You can fasten the ground cable to the workbench with a C-clamp, attach a spring-loaded clamp directly onto the work piece, or bolt or tack-weld the end of the ground cable to the welding bench. The third way creates a permanent common ground.


Cleaning Equipment

Strong welds require good preparation and procedure. The surface area of the work piece must be free of all foreign material, such as rust, paint, and oil. A steel brush is an excellent cleaning tool and is an essential part of the welder’s equipment. After initial cleaning and a weld bead has been deposited, the slag cover must be removed before additional beads are added. The chip-ping hammer was specifically designed for this task. The chipping operation is then followed by more brushing, and this cycle is repeated until the slag has been removed. When the slag is not removed, the result is porosity in the weld that weakens the weld joint.
Cleaning can also be accomplished by the use of power tools or chemical agents. If these items are used, it is essential that all safety precautions are followed.


Safety Equipment

Arc welding not only produces a brilliant light, but it also emits ultraviolet and infrared rays that are very dangerous to your eyes and skin. Personal safety items include helmets, lenses, and gloves. An important item that needs to be covered here is welding screens. The welder not only has to protect himself but he also must take precautions to protect other people who may be working close by. When you are welding in the field, you must install a welding screen around your work area. It can be an elaborate factory-manufactured screen or as simple as one constructed on site from heavy fire-resistant canvas.

Another area often overlooked is ventilation. Welding produces a lot of smoke and fumes that can be injurious to the welder if they are allowed to accumulate. This is especially true if you are welding in a tank or other enclosed area. Permanent welding booths should be equipped with an exhaust hood and fan system for removal of smoke and fumes.


Questions and comments

Sam

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I use Aloe for arc burns- from a plant not the canned stuff. Put it in the eye = feels like a million bucks.

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i like the thuroughness of the post. but shouldnt you also talk about brazing and soldering? along with the different welder types? as in a tig or mig?

and i know this sounds completely self explanitory, but under the saftey section:
ALWAYS:
wear long pants (denium preferrably)
wear LONG sleved shirt ( denium or a shirt that is specifically tagged for welding purposes)
wear thick soled, leather steel toe boots. (leather and steel toes are a must. and i reccomend the steel toes that come with the arch protector in the tounge)
make sure your lense is the correct lense for your welding type (ive seen men use lenses for O/A tanks to stick weld with)
wear full leather gloves. no cloth is allowed here. NO EXCEPTIONS! (i also reccomend the ones that have the extra cuff length. leather only of course)

NEVER:
wear short pants or short sleeved shirts.
wear a tennis shoe or even a hiking boot to do this.
touch a weld barehanded before 5minutes have passed (might look cooled but it probably isnt)
attempt light a cigarette off a fresh weld. (it is a dumb thing to do, i should know)
weld when it is damp out, this only applies to when you operate your welder outside. unless you are in a real buiding with no moisture, then dont weld when wet.

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I'll have the next one up in a few days , Welcome to the Site Gypsyfeet . I'll do my best to help you get welding good and in to forging some in a short time , even welders forge their Chipping hammers and make a few tools to suit themselves for jobs to be done . Work on the safety Equipment First . that is Important when welding and forging .

Blessings and Best Regards ,

Next Section will be up in A few days .
( Starting with a few simple welding rods and what the Numbers mean on them )

Sam

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Clinton ,
The use of Aloe is fine for a sun burn and/or an arc burn from welding on most occasions . However Safety equipment worn correctly prevents this from happening and is recommended . as for ones Eyes you only have 2 things that come in pairs on the body need proper protection when doing Any type of work 2 ears = ear protection , 2 eyes the proper Eye protection I.E clear, shaded, or Cutting Glasses ,face shield Hoods , 2 Feet = proper shoes or boots , 2 hands = gloves for the work being done .
As for your eyes A flash burn to the eyes is a serious issue , go to the Eye Doctor ! ! ! they deal with it ALL the time , and they can / could save your sight and keep you from being blind.

Ramsies,
I will cover the different “welder” type of Machine, also “Weldor”, which term distinguishes the tradesman from the equipment used to make welds, is a tradesman who specializes in welding materials together. Also I will cover the types of Welding processes. ( later in the next course , writing a lesson plan from my memory and books has been a bit for me as the class / course gets under way they will get better .
Your warnings and cautions are good for the clothing with one exception the Steel toe is now composite material much do to the nature of steel toe shoes and boots chopping off the toes of folks. It is accepted to use them, however with the composite type, it offers protection and in the case of a heavy object, being dropped on one’s foot the toe may be mashed but not cut off like the steel cap.

To the Welding 101 folks ,
I am sorry for the delay on the course as I am trying to do a few of the lesson plans ahead , after this I should be able to post /hold class and chat with / answer and questions over the information posted .
Thank you for understanding
Best Regards

Sam

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When welding in the field or sometimes in a shop environment you can get arc burn from a reflection or from someone welding behind you. It may or may not be severe, in either case it came from an unpredicted source.

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i know the steel toes are now a composite, lol, but steel toe is more recognizable than composite toe. and thank you for the praise. it is much apprieciated.

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Clinton,
yes it happens All the time flash welds that is the Aloe for eyes is not a chance I want to take I like seeing my kids not just hearing them .

Sam

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"Fusion welding" refers to melting metal together. However, in forge welding and ultrasonic welding, there is no melting. Furthermore, experiments have been done in outer space where highly polished specimens with plane surfaces have been
"cold welded," placed together and cohesion took place. No heat. It's cold out there.

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fusion - the act of fusing (or melting) together.,the state of being combined into one body.,The merging of different elements into a singular mass.

Sam

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"Fusion welding" refers to melting metal together. However, in forge welding and ultrasonic welding, there is no melting. Furthermore, experiments have been done in outer space where highly polished specimens with plane surfaces have been
"cold welded," placed together and cohesion took place. No heat. It's cold out there.


The bolded section fascinates me. The concept of creating structural members that could be directionally strengthened via layer welding is something that I've puzzled over how to do economically for quite some time. Combine that with the possibility of asteroid mining in about 100 years and this could be the way to go.

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"Fusion welding" refers to melting metal together. However, in forge welding and ultrasonic welding, there is no melting. Furthermore, experiments have been done in outer space where highly polished specimens with plane surfaces have been
"cold welded," placed together and cohesion took place. No heat. It's cold out there.

the outerspace bit is somthing i find neat, think of it gents, one day when the people of earth decide to colonate a different planet(and yes, we probably will, alot of money is going into extensive reaserch on an earth substitute for when we mess up this planet enough, we can move to another) but think of it lads! you need a building? while they are researching the planet for how we can colonize, we can "weld" houses and other structures WITHOUT ELECTRICITY and then just push them into new earth! oh how neat that will be!

doing great by the way, though i havent to agree with frank "fusion welding" is a point in which two base metals are melted (or heated really hot and beaten) together. welding in the sense that everyone thinks of is where you have your base metals and then you intoduce a filler metal to them.

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. welding in the sense that everyone thinks of is where you have your base metals and then you intoduce a filler metal to them.


I think that the term "Everyone" is rather broad, as well as incorrect

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well, i guess your right about that. as i do tend to be incorrect about somthings. but i guess what i should say is : the general population minus anyone with metalworking experience.

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ya know, there is a major difference between bonding and fusion. Bonding is joining as substance without actually fusing them together. Welding is actually a thermo molecular restructuring of the parent materials in order to fuse them together in a permanent state. The job I am presently in is referred to as carbide welding....it's brazing with carbide in a nickel-silver matrix...a bonding process. As far as fusing aka welding carbon steel to stainless....chromium steel...a 309 or 308 filler works well, be it SMAW or GMAW.

 I kinda figure certifications are just paper....you can weld or you can't.

Personally I've certified Section 8 and 9 (r,s and u stamps) API WSMA1104 6g, mil std 248c/271, AWS D1.1-98 1-1 2g GMAW, AWS D1.1-98 WSMAW 1-3 2g, AWS D1.1-98 WFCAW 1-2 2g, AWS D1.2-97 WGMAW 23/23 2g, SMAW 6g 6016-7018, QW-302 through QW-305,6gt 2202-2222.1, ETI AWS D1.1 QW-150 WFCAW, ASME section 8-4 and1 pressure vessel, NYCDOT 811.3-SMAW 1g 2g 1f 2f and BMP 03.012-03.015, 03.017, 03 020, 03.021, 03.032 and finally 03.057. There where more but I didn't document them.

 

The above mentioned certs where only stated to validate that I know NOTHING about welding and joining. I learn something new every day...I've only been doing it since 1979.

 

Integrity is doing what's right regardless who's watching 

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