Course Description
Gas Tungsten Arc Welding (GTAW) Principles introduces the fundamental techniques of GTAW — universally called TIG welding in the shop — and provides supervised practice developing them. Students begin on plate, establishing torch control, filler metal feed, arc length, and puddle management, and progress to combining GTAW with shielded metal arc welding in applications that use both processes on a single weldment.
Within the SCNS taxonomy, PMT is the Precision Metalworking prefix, and the 0-level number identifies this as a postsecondary adult vocational (PSAV) clock-hour course. It is measured in 90 clock hours and carries zero college credits. It appears at approximately five Florida institutions within PSAV Welding Technology programs.
GTAW is the process that separates a competent welder from a highly employable one. It is the slowest of the common processes and the most demanding of manual skill — the welder controls the arc with one hand, feeds filler with the other, often modulates amperage with a foot pedal, and does all of it while maintaining a gas shield that will ruin the weld if disturbed. It is also the process required for aluminum, stainless steel, titanium, thin-wall tubing, and code work in aerospace and food and pharmaceutical processing. Students should expect this course to be harder than the SMAW and GMAW courses that precede it, and should expect the first several sessions to produce nothing usable. That is normal.
⚠ Sequence-position drift: the roman numeral in the title is local
Daytona State titles this course "Welding VII (Gas Tungsten Arc) and Lab". Florida course inventories circulate it as "Gas Tungsten Arc Welding Principles." The "VII" is Daytona State's position in its own program sequence — it says nothing about where the course falls at another institution, and a different Florida college may teach the identical content as its Welding IV or Welding V.
The same caution applies to hours. Related PMT courses in this repository run at 50, 75, and 150 clock hours depending on the occupational completion point they serve, and the 90-hour value here reflects Daytona State's catalog. Sequence courses by the SCNS number and the published prerequisite chain, never by the roman numeral in a local title, and read the program's own FLDOE curriculum framework for hours.
Learning Outcomes
Required Outcomes
- Describe the GTAW process: the tungsten electrode, the inert gas shield, the arc, and the separately added filler metal.
- Set up a GTAW station: machine polarity and current type, gas supply and flow rate, torch assembly, and workpiece connection.
- Select the correct tungsten electrode type and diameter for the base metal and current, and grind and prepare the electrode correctly.
- Select and set the correct shielding gas and flow rate, and recognize the weld defects caused by inadequate or turbulent shielding.
- Explain the difference between DCEN, DCEP, and AC output and select the correct one for carbon steel, stainless steel, and aluminum.
- Select filler metal by AWS classification appropriate to the base metal.
- Establish and maintain an arc, control arc length, manipulate the puddle, and add filler metal at a consistent rate.
- Produce acceptable GTAW welds on carbon steel plate in the flat and horizontal positions, on fillet and groove joints.
- Produce acceptable GTAW welds on stainless steel, controlling heat input, distortion, and oxidation.
- Apply joint preparation, fit-up, cleaning, and tack welding practices appropriate to GTAW.
- Combine GTAW root passes with SMAW fill and cover passes on a single weldment.
- Perform visual inspection of a completed weld and identify discontinuities: porosity, tungsten inclusion, lack of fusion, undercut, cracking, and oxidation.
- Diagnose the procedural cause of a defect and correct the technique or setting that produced it.
- Apply all applicable safety practices, including personal protective equipment, ventilation, compressed gas handling, and electrical safety.
- Read and follow a welding procedure specification (WPS).
Optional Outcomes
- Produce acceptable GTAW welds on aluminum using AC output and appropriate cleaning and preheat practice.
- Weld pipe and tubing using GTAW, including open root technique.
- Apply back purging techniques for stainless steel and reactive metals.
- Weld out of position — vertical and overhead — using GTAW.
- Prepare for and take an AWS or employer performance qualification test.
- Describe orbital and automated GTAW applications.
Major Topics
Required Topics
- GTAW process fundamentals and comparison to SMAW, GMAW, and FCAW
- Power sources, current type and polarity, high-frequency start, and pulse settings
- Torch components, collets, cups, gas lenses, and consumable selection
- Tungsten electrodes: alloy types, color coding, selection, and grinding
- Shielding gases: argon, helium, and mixtures; flow rate, coverage, and post-flow
- Filler metals and AWS filler classification
- Base metal preparation, cleaning, and fit-up
- Arc starting, arc length control, torch angle, and travel speed
- Puddle control and filler metal addition technique
- Welding carbon steel with GTAW: settings and practice
- Welding stainless steel: heat input, distortion, oxidation, and back purging
- Joint types and welding positions; flat and horizontal fillet and groove welds
- Combination process work: GTAW root with SMAW fill and cap
- Weld discontinuities, visual inspection, and defect diagnosis
- Welding procedure specifications and welder qualification concepts
- Shop safety: PPE, ventilation, compressed gas, electrical, fire watch, and hot work
Optional Topics
- Aluminum GTAW: AC balance, cleaning action, oxide removal, and preheat
- Pipe and tube welding, open root and consumable insert techniques
- Out-of-position GTAW
- Reactive and exotic metals: titanium, nickel alloys, and purge requirements
- Nondestructive examination methods and destructive bend testing
- Code welding: AWS D1.1, AWS D1.6, AWS D17.1, and ASME Section IX
- Automated and orbital GTAW
Resources & Tools
- Welding: Principles and Applications (Jeffus) — the most widely adopted welding text in Florida programs.
- Modern Welding (Althouse et al.) — the other standard, common in secondary and PSAV programs.
- AWS D1.1 Structural Welding Code — Steel; AWS D1.2 (aluminum), AWS D1.6 (stainless), AWS D17.1 (aerospace), and ASME Boiler and Pressure Vessel Code, Section IX — the standards that govern qualified welding in the industries this course leads to.
- AWS A5.18, A5.9, A5.16 and related filler metal specifications.
- American Welding Society (aws.org) — certification pathways, SENSE program materials, and technical resources.
- Equipment: constant-current GTAW power sources with AC and DC output and high-frequency start, torches (air- and water-cooled), foot pedals, gas lenses, tungsten grinders with dedicated dust collection, purge equipment.
- Consumables: tungsten electrodes, argon and argon-helium mixes, filler rod in carbon steel, stainless, and aluminum.
- Inspection tools: fillet weld gauges, undercut gauges, and bend test fixtures.
Career Pathways
- TIG welder / fabricator — the immediate destination, and the process that commands the highest hourly rates among manual welding jobs.
- Aerospace welder — Florida's Space Coast is one of the densest aerospace manufacturing corridors in the country. Blue Origin, SpaceX, Lockheed Martin, Northrop Grumman, L3Harris, and their supplier base all require GTAW under AWS D17.1, and these are among the best-paid welding jobs in the state.
- Marine and yacht fabrication — Fort Lauderdale, Riviera Beach, Tampa, and Jacksonville support a large marine industry where aluminum and stainless GTAW work is constant.
- Food, beverage, and pharmaceutical process piping — sanitary stainless tubing welded to high standards; Florida's beverage, citrus, and pharmaceutical processing plants hire for this specifically.
- Power generation and pipe welding — utility and industrial maintenance, including FPL and Duke Energy facilities and their contractors; GTAW root passes are standard on code pipe.
- Motorsports, custom fabrication, and specialty shops — chassis, roll cages, exhaust, and aluminum work.
- Welding inspector (CWI) and welding educator — later-career paths requiring AWS certification and documented experience.
- SOC code 51-4121 Welders, Cutters, Solderers, and Brazers. Florida's welding workforce demand is driven by aerospace, marine, construction, and an aging incumbent workforce.
Special Information
⚠ Safety: the hazards specific to GTAW are not the ones students expect
Every welding student learns about arc eye and burns. GTAW carries several hazards that are less obvious and, over a career, more consequential.
- Thoriated tungsten electrodes are radioactive. Thorium-232 is a low-level alpha emitter. The hazard is not the electrode sitting in the torch — it is grinding it, which produces respirable radioactive dust that can be inhaled and retained. This is a genuine, documented occupational exposure and it is routinely glossed over in shops. Use a dedicated grinder with local exhaust and a collection system, never a shared bench grinder, and prefer ceriated, lanthanated, or rare-earth electrodes, which perform as well or better on most work and are not radioactive. Many aerospace and institutional shops have eliminated thoriated tungsten entirely.
- Hexavalent chromium is produced when welding stainless steel — and stainless is a primary GTAW material. Cr(VI) is a confirmed human carcinogen regulated by OSHA under 29 CFR 1910.1026, with a permissible exposure limit low enough that ordinary shop ventilation may not meet it. Local exhaust ventilation at the arc, not a fan blowing across the shop, is the control that works.
- Argon is an asphyxiant and is heavier than air. It displaces oxygen and pools in low areas, tanks, and pits. Purging the inside of a vessel or pipe and then reaching into it is a recognized confined-space fatality mechanism. Purge gas is invisible, odorless, and gives no warning.
- Ozone and ultraviolet radiation are unusually intense in GTAW because the arc is open and clean, with no flux smoke to absorb UV. Skin exposure produces burns through a single shift, and reflected UV burns skin that was never facing the arc. Cover all skin; the classic injury is a sunburned neck under an open collar.
- High-frequency arc start generates electromagnetic interference that can affect implanted medical devices such as pacemakers. Anyone with an implanted device must clear GTAW work with a physician.
None of this argues against the process. It argues for controls that are cheap now and impossible to retrofit onto a lung.
⚠ This is a PSAV clock-hour course — it does not transfer as college credit
PMT0131C is 90 clock hours with zero college credit. PSAV coursework does not transfer to a college-credit program the way a 1000- or 2000-level course does. What exists instead is articulation — Florida's statewide Gold Standard Career Pathways agreements and local articulation agreements may award credit toward a related A.S. degree for completing an entire PSAV program or an occupational completion point, not for individual courses, and not automatically. Students planning to continue into an A.S. in Engineering Technology or a related program should obtain a written evaluation from the receiving institution before assuming credit will follow.
What PSAV welding does produce is direct employability, and in this trade that is worth more than the transcript. Employers hire on a performance qualification test, not on a course grade.
⚠ Career honesty: the certificate does not certify you — the test does
This is the point that most changes how a student should approach the course. Completing a welding program does not make a person a "certified welder." Welder certification is a performance qualification to a specific procedure, on a specific material, thickness, joint, and position, witnessed and documented — under AWS D1.1, ASME Section IX, AWS D17.1, or an employer's own procedure. It belongs to the employer or the certifying body, it is specific to what was tested, and it expires or lapses if the welder does not maintain continuity in that process.
The practical consequences: a welder qualified on carbon steel plate is not thereby qualified on stainless pipe; a lapsed qualification must be retested; and moving to a new employer usually means testing again on day one. Students should use lab time to build the ability to pass a test cold, because that is the hiring gate. The credential the course gives is skill; the paperwork comes from the test.
Course format, cost, and time expectation
PMT0131C is a laboratory-intensive course — the great majority of the 90 hours is time under the hood. Daytona State offers it fall, spring, and summer, lists PMT0134C as a corequisite, and attaches a substantial lab fee ($407.62), which reflects real consumable cost: argon, tungsten, filler rod, and base metal are expended in quantity while learning. Expect graded performance projects judged by visual inspection and, in many programs, destructive bend testing — a weld either passes or it does not, and partial credit is rare.
Students should also plan for personal equipment. A quality auto-darkening helmet, TIG-specific thin gloves that permit filler feel, a jacket, and safety glasses are ordinary personal purchases in this trade, and cheap gloves in particular make GTAW harder than it needs to be.
Position in the program
GTAW normally comes late in a welding program because it builds on puddle control developed in SMAW and GMAW. Daytona State's designation as "Welding VII" reflects that placement. Students who found SMAW and GMAW straightforward should still expect a difficult adjustment: GTAW is a two-handed, sometimes three-limbed coordination task, and progress in the first two weeks is genuinely slow for nearly everyone. Consistent shop time matters far more here than in the earlier courses.