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Starvard University · Welding 101
You will understand the main welding processes, the safety habits that come before any arc is struck, and the practice path toward entry-level work. This course teaches theory in plain words, grounded in OSHA and NIOSH safety guidance and Bureau of Labor Statistics career facts. Real welding skill is learned hands-on with an instructor, and this course will say so plainly whenever it matters.
Hello, my name is Finn, and I'm going to help you understand this course.
Here it is, explained like you are 10:
Welding joins pieces of metal by melting them together with great heat. It is strong, useful work, but the light can hurt your eyes, the smoke can hurt your lungs, and sparks can start fires. This course teaches the safety rules first, then explains stick, MIG, flux-core, and TIG welding in plain words, so you know what each job does before you ever practice with a teacher.
OSHA, the federal workplace safety agency, describes hazards from welding that include metal fumes, ultraviolet radiation, burns, eye damage, and electric shock, and says many can be controlled with proper work practices and personal protective equipment. NIOSH adds that welding fumes can contain metals such as manganese and chromium, and that confined spaces can raise exposure.
The lessons build in order. You start with careers and safety, learn how heat changes metals and how joints and symbols work, then meet each process one at a time. Cutting, inspection, and certification preparation close the course. Nothing here replaces hands-on training: you learn the language, the rules, and the reasons, so supervised practice makes sense from the first day.
The whole course in brief
What you will be able to do after this course
The twelve lessons
Lesson 1
Welders join, repair, and cut metal in construction, manufacturing, shipbuilding, and repair shops. The Bureau of Labor Statistics counted 437,700 jobs for welders, cutters, solderers, and brazers in 2025, and most workers in the occupation work full time, sometimes outdoors and sometimes indoors in tight spaces. The work is physical and practical: you read a drawing, prepare the metal, make the weld, and check that it holds.
The typical entry path is a high school diploma or equivalent, combined with technical training and moderate-term on-the-job training, in the words of the Bureau of Labor Statistics. The median annual wage was $53,750 in May 2025, or $25.84 per hour. Employment is projected to grow 2 percent from 2025 to 2035, slower than average, yet about 40,300 openings are projected each year as workers retire or move to other jobs.
Certification is proof that you passed a hands-on test making a sound weld in a set process and position, judged against a standard. Employers and training programs use such tests because a certificate tells them your weld held up under inspection, not just that you attended class. This course teaches theory only. Real welding skill is learned hands-on with an instructor, in a booth, with real metal, real feedback, and time to practice.
Lesson 2
Safety comes before technique, every time. Never weld without personal protective equipment and ventilation, and never take a shortcut with either one. Wear a welding helmet with the correct shade for the work, flame resistant gloves and a jacket or sleeves that protect your arms, sturdy boots, and clothing that covers your skin. Wear pants without cuffs, because cuffs can catch sparks and hot metal. Put safety glasses on under the helmet, so your eyes stay protected when you lift the helmet to chip or inspect.
The arc can burn eyes and skin with ultraviolet radiation, a painful injury often called arc eye, and sparks and hot slag cause burns. Welding smoke is a real hazard too. OSHA says general ventilation moves fresh air through the area, local exhaust removes fume at the source, and you should position yourself to keep fume away from your breathing zone, staying upwind outdoors. Do not weld in confined spaces without ventilation. If ventilation and work practices do not reduce exposure to safe levels, respiratory protection may be required. Stainless steel deserves special respect: OSHA explains that chromium in stainless steel is converted to its hexavalent state during welding, and that hexavalent chromium fume is highly toxic, can damage the eyes, skin, nose, throat, and lungs, and can cause cancer.
Fire discipline is strict. OSHA requires that, where practicable, all combustibles be relocated at least 35 feet from the work site, or shielded if they cannot move. A fire watch is required in the situations OSHA lists, including when appreciable combustible material is closer than 35 feet, and the fire watch shall be maintained for at least a half hour after welding or cutting ends, to catch smoldering fires. Welding galvanized steel is especially dangerous: its zinc coating makes zinc fumes that can cause metal fume fever, an illness with flu like symptoms, so avoid welding it where you can, and where you cannot, use the ventilation and respiratory controls OSHA describes and clean the coating back from the joint under instructor guidance.
Lesson 3
Most welding is done on steel, which is iron with carbon and other elements added. Mild steel is common, forgiving, and widely used for frames, repairs, and fabrication. Stainless steel contains chromium, which OSHA notes is added to alloy steel to increase hardenability and corrosion resistance. That is why stainless resists rust. Aluminum is lighter and conducts heat quickly, so it behaves differently under the arc and takes practice to control.
Heat changes metal in ways you can see and ways you cannot. Metal expands as it heats and shrinks as it cools, and uneven heating and cooling can pull a part out of shape, which welders call distortion or warping. The area beside the weld, often called the heat affected zone, can become harder or softer than the rest of the piece. Fast cooling can leave some steels hard and brittle, while slow, even cooling is gentler on the finished joint.
Coatings change the job completely. Paint, oil, rust, and solvent residue should be cleaned off before welding, because OSHA warns that welding surfaces should be cleaned of any coating that could create a toxic exposure. Galvanized steel carries a zinc coating, and welding it makes zinc fumes linked to metal fume fever, covered in Lesson 2. Treat coated metal as a warning sign: identify the coating first, ask how it will be handled, and never assume shiny metal is safe metal.
Lesson 4
A joint is where the pieces meet, and five basic types cover most work. A butt joint places two pieces edge to edge in the same plane, like two plates forming one flat sheet. A lap joint overlaps one piece over another. A tee joint meets at a right angle, like a post on a plate. A corner joint meets at the edges of two pieces, and an edge joint joins the edges of pieces lying side by side.
Each joint can be welded with different weld types. A groove weld fills a prepared opening between pieces, often with the edges shaped so the weld can reach deep. A fillet weld is roughly triangular and joins surfaces at an angle, as in tee and lap joints. Choosing the joint and weld together is a design decision: the load the part must carry, the thickness of the metal, and access for the torch or electrode all shape the choice.
Position describes the direction you weld in. The four basic positions are flat, horizontal, vertical, and overhead. Flat is usually the easiest to learn, because gravity helps the molten metal stay in the joint. Overhead is the hardest, because gravity pulls the molten metal down toward you. Certification tests are given by process and position, so a welder qualified in the flat position is not automatically qualified overhead, and practice in each position matters.
Lesson 5
A blueprint tells you what to build: the shape, the size, and how the parts fit. A welding symbol is the shorthand on that drawing that tells you what weld to make, where to make it, and how big it should be. Learning to read symbols means a drawing made in an office can become correct work in your hands, without guessing and without asking someone to redraw it in words.
The symbol is built around a horizontal reference line with an arrow pointing to the joint. The arrow side is the side the arrow touches, and information placed below the line generally refers to that side, while information above the line refers to the other side of the joint. A small triangle in the symbol means a fillet weld. Other shapes stand for groove welds of different edge preparations, so the shape itself is an instruction about how the edges should be prepared.
Read a drawing in a steady order. First find the joint and the arrow. Next read the weld type and its size, then its length and spacing if the weld is not continuous, and finally any tail note, which can carry extra instructions such as the process to use. Check the measurements on the drawing against the real pieces before you weld. A symbol you misread becomes metal you must cut out, so slow reading at the start is fast work in the end.
Lesson 6
Stick welding, formally shielded metal arc welding or SMAW, is one of the oldest and most versatile arc processes. OSHA describes its electrode as providing both flux and filler material. An electric arc melts the base metal and the end of a coated rod, called the electrode or stick. The rod becomes the filler metal that fills the joint, while its flux coating burns and forms a shielding gas and a protective slag layer over the hot weld.
That self shielding design is why stick welding works well outdoors and on construction and repair work, where wind would blow away a separate shielding gas. It is used on steel in many thicknesses, on farm and heavy equipment repairs, and on structural work. The equipment is comparatively simple and portable: a power source, cables, an electrode holder, a ground clamp, and rods kept dry and matched to the metal and position.
The skills to practice, always with an instructor, are striking the arc without sticking the rod, holding a steady arc length and travel angle, moving at an even speed, and reading the molten puddle. After the weld cools, you chip away the slag and inspect the bead. Expect early welds to look rough. Stick welding rewards patience and repetition, and its fume still demands the ventilation from Lesson 2, because OSHA ranks it among the higher fume arc processes.
Lesson 7
MIG welding, formally gas metal arc welding or GMAW, feeds a continuous wire electrode through a gun. OSHA describes it as widely used, with a consumable electrode for filler metal and an external gas shield. The wire melts into the joint as filler, while shielding gas flowing from the gun pushes air away from the molten metal, protecting it as it solidifies. A wire feeder keeps the wire coming at a steady rate you set.
Because the wire feeds continuously, MIG welding has no rod changes and can lay metal quickly and neatly. It is common in manufacturing, auto body work, and fabrication shops, and many beginners find its puddle easier to see and control than stick welding. The same gun based setup is less happy outdoors, because wind can disturb the shielding gas, and clean metal matters, because the process has no flux to handle dirt and rust for you.
The basics to learn under instruction are wire feed speed and voltage settings, gun angle, contact tip distance, and a steady travel speed that keeps the puddle the same size from start to finish. Listen as you learn: experienced welders describe a good MIG arc by its steady sound. And remember the fume order in the OSHA fact sheet: MIG welding generally produces less fume than flux-core and stick welding, but less is not none, so ventilation stays on.
Lesson 8
Flux-core welding, or FCAW, also feeds a continuous wire through a gun, but the wire is a tube filled with flux. OSHA lists its filler metal electrode with a flux shield. As the wire melts, the flux inside creates shielding that protects the weld, much as the coating does in stick welding, and it leaves a slag covering to chip away afterward. Some flux-core wires are self shielded, and others also use an external shielding gas.
The process is valued for speed and deep penetration on thicker steel, and self shielded wire is popular for outdoor construction and repair, because it does not depend on a gas bottle that wind can defeat. It is common on structural steel, heavy equipment, and ship and field work. The trade off is housekeeping and air quality: flux-core makes more smoke and spatter than MIG welding, and the finished weld needs slag removal before painting or the next pass.
OSHA places flux core arc welding at the top of its list of arc types in order of decreasing fume production. Read that as a direct instruction: position local exhaust close to the arc, keep your head out of the plume, and check that general ventilation is actually moving air. The technique basics mirror MIG welding, with settings, gun angle, and travel speed matched to the wire, plus the discipline to clean slag between passes so defects are not buried.
Lesson 9
TIG welding, formally gas tungsten arc welding or GTAW, uses a tungsten electrode that does not melt away. OSHA describes it as giving a superior finish, with a non-consumable electrode and an externally supplied inert gas shield. The arc from the tungsten melts the base metal, the shielding gas protects the puddle, and filler metal, when needed, is fed in by hand as a separate rod. One hand holds the torch, the other feeds filler, and many welders control the heat with a foot pedal.
Because the welder controls heat and filler separately, TIG welding gives precise, clean welds with little spatter and no slag. It is used where appearance and accuracy matter: stainless steel work, aluminum parts, thin materials, pipe, and repairs where a neat finish is part of the job. It is also the slowest of the four processes in this course, and the hardest to coordinate at first, because both hands and a foot may be working at once.
Cleanliness is the TIG rule. The metal, the filler rod, and the tungsten must be clean, and the shielding gas coverage must stay steady, or the weld will be contaminated and weak. OSHA lists TIG welding at the low end of fume production among arc processes, which fits its clean reputation, but the arc is intense and eye and skin protection are just as necessary. Learn it after stick or MIG basics, with an instructor watching your hands.
Lesson 10
Cutting is welding in reverse: instead of joining metal, you separate it with heat. Oxy-fuel cutting uses a flame from burning a fuel gas, usually acetylene, mixed with oxygen, the same kind of flame OSHA describes for gas welding. The flame preheats the steel, then a jet of pure oxygen does the cutting, burning through the heated metal and blowing the molten material away. It can cut thick steel and needs no electrical power at the torch.
Plasma cutting uses an electric arc to turn a jet of gas into a very hot plasma stream that melts through metal and blows the melt away. It cuts quickly and neatly, works on many conductive metals including stainless steel and aluminum, which oxy-fuel cutting handles poorly, and is common in fabrication shops and scrap and repair work. Both processes produce sparks, hot slag, fumes, and bright light, so the fire, eye, and ventilation rules from Lesson 2 apply in full.
Set up a cutting job like a welding job. Clear or shield combustibles, with the 35 foot rule and a fire watch where OSHA requires one, keep cylinders secured and hoses in good condition, wear the correct eye protection for cutting, and plan where the cut piece will fall. A piece of hot metal dropping where you did not expect it can burn you or start the fire you worked to prevent. Cutting is a skill of its own, learned hands-on, torch in hand, with supervision.
Lesson 11
Inspection starts with your eyes, good light, and a clean weld. Chip the slag, brush the surface, and look along the whole joint, not just the middle. A good weld has a reasonably even width and height, smooth transitions into the base metal, full coverage where the drawing asked for it, and no visible cracks. What you are checking is simple to say: did the two pieces truly become one sound piece of metal?
Learn the common defects by sight. Porosity is small holes in the weld, often from contamination or lost shielding. Undercut is a groove melted into the base metal beside the weld and left unfilled, weakening the edge. Incomplete fusion means the weld did not fully join to the base metal or to the previous pass. Cracks are the most serious defect, because a crack can grow under load. Excess spatter, uneven beads, and slag trapped inside the weld all point to settings or technique that need correction.
Inspection is also a record and a habit of honesty. Training and certification tests judge welds by examination and, in some testing, by bending or other destructive checks that reveal hidden flaws. In real work, a defect you find and repair is a success, while a defect you hide can fail under load and hurt someone. When in doubt, ask an experienced welder or inspector to look. Good welders inspect their own work critically, fix what they find, and keep notes on what caused each flaw.
Lesson 12
A certification test asks you to make a specific weld, in a specific process and position, on metal of a set thickness, that then passes examination. Preparation is therefore specific too. Find out exactly which test you will take, what it allows, and how the finished weld will be judged, well before test day. Study the safety rules and the theory from this course, because understanding why a setting matters helps you recover when a practice weld goes wrong.
Practice should imitate the test. Use the same process, position, and joint type, work within any time expectations, and inspect every practice piece the way an examiner will, cleaning it and hunting for the defects from Lesson 11. Keep a short log of each practice weld: settings, what the weld looked like, and what you changed next time. Patterns appear quickly in a log, and fixing one repeating flaw is the fastest way to improve before the test.
Arrive ready in body and gear. Bring your own helmet with the correct shade, gloves, jacket, and safety glasses if the test site allows personal gear, confirm the site rules in advance, and give yourself time to set up calmly. Remember the honest frame of this whole course: it taught you theory, vocabulary, and safety. Real welding skill is learned hands-on with an instructor, and the welders who pass are the ones who practiced under that kind of guidance until a good weld became their normal weld.
Sources
This course is built from the free safety and career guidance of the United States government. OSHA and NIOSH supply the safety, fume, and protective equipment guidance, and the Bureau of Labor Statistics supplies the career, pay, and outlook facts. Every process description, hazard warning, and pay figure in the lessons traces to one of these official sources.
Graduation
You learned what welders do and earn, the protective gear and ventilation that come before any arc, the warning on galvanized steel and its zinc fumes, how heat changes metals, the joints, positions, and symbols that describe a job, and how stick, MIG, flux-core, and TIG welding and cutting each work. You can inspect a weld for common defects and prepare for a certification test, knowing that real skill comes from hands-on practice with an instructor.
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