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newSchoolWorks.com › VoTechWorks › Building & Construction › Welding › Gas Metal Arc Welding (GMAW) › Lesson 9
BLD-WELD01-04 · Lesson 9 · 12 clock hours · practice

Capstone Performance Welds and Portfolio Completion

Objective. Students will independently produce a complete set of GMAW performance welds (1F, 2F, 3F, 1G) to AWS D1.1 visual acceptance criteria, assemble a process portfolio documenting their WPS interpretation, machine setup records, inspection logs, and bend test results, and present their best weld pair to the instructor in a structured review.

Capstone Performance Welds and Portfolio Completion

This lesson is the culmination of your GMAW course. You will work independently to produce four performance welds, assemble a professional process portfolio, and present your work in a structured review. Every skill you have practiced—machine setup, WPS interpretation, safety compliance, visual inspection, and self-assessment—comes together here.

Safety Reminders Before You Strike an Arc

Because no instructor coaching is provided during the performance weld session, you are fully responsible for your own safety decisions. Before you begin:

Understanding the Four Performance Welds

You will complete one weld in each of the following positions using the WPS you have already interpreted:

Selecting and Applying Your WPS

Select the WPS from your student-completed set that matches the base metal, filler metal, and position for each coupon. For every weld, confirm these essential variables before you strike an arc:

1. Filler metal: ER70S-6, 0.035-inch diameter.

2. Shielding gas: C25 (75% Argon / 25% CO₂) at the flow rate stated on your WPS—typically in the range of 15–25 cubic feet per hour, but use your documented value.

3. Voltage and wire feed speed: Set to the ranges on your WPS for the material thickness (¼-inch A36 plate). Record the actual dial settings on your machine setup card.

4. Travel speed and angles: Work angle and travel angle vary by position; review your notes for each position before tacking.

5. Preheat: For ¼-inch A36 plate at normal shop temperature, preheat is generally not required, but follow your WPS.

Record every actual setting on your machine setup card immediately after dialing in—do not fill it out from memory after the fact.

AWS D1.1 Visual Acceptance Criteria — What the Inspector Checks

All four welds will be visually inspected against AWS D1.1 criteria. Know these standards:

After visual inspection passes, your 1G groove weld coupon is prepared and loaded into the guided-bend jig for a face-bend test. The root of the bend is the face of the weld. After bending, examine the convex surface for cracks or other discontinuities exceeding the code's acceptance limit.

Assembling Your Portfolio

A professional portfolio demonstrates that you can document your work to industry standards. Organize your binder or digital folder with a table of contents and these required sections in order:

1. Lab log sheets from every GMAW lesson

2. Process logs (voltage, amperage, wire feed speed, gas flow records)

3. Defect logs with sketches or photos and corrective actions taken

4. Bend test inspection reports

5. Safety audit checklists

6. Machine setup cards

7. Your student-completed WPS set

8. One-page written reflection

The written reflection must identify your most significant skill improvement during the course, explain what caused the problem, and describe specifically how you corrected it. Use correct GMAW and AWS terminology throughout.

The Structured Weld Review Presentation

You will present your 1G groove weld and one fillet weld to your instructor. Plan to cover:

The instructor will ask three to five follow-up questions. Answer using correct AWS terminology. If you do not know an answer, say so honestly—do not guess at code requirements.

Setting Yourself Up for Success

Arrive early enough to inspect and clean your machine, confirm gas flow at the nozzle, and run a short test bead on scrap before your performance welds. Budget your time: four welds plus tacking and cleanup typically take a full lab session. Quality over speed—a rejected weld requires a complete restart with a new coupon.

Key terms10

WPS (Welding Procedure Specification)A written document that prescribes the essential, supplementary essential, and nonessential variables required to make a weld that meets code requirements; the welder must follow it exactly during qualification and production welding.
Essential VariableA WPS parameter whose change, such as filler metal classification or position, requires requalification of the weld procedure because it affects mechanical properties or soundness.
1G / 2F / 3F Position DesignationsAWS standardized codes describing weld orientation: the number indicates position (1=flat, 2=horizontal, 3=vertical, 4=overhead) and the letter indicates joint type (F=fillet, G=groove).
AWS D1.1 Visual Acceptance CriteriaThe specific limits on weld discontinuities—such as undercut depth, porosity size and frequency, crack prohibition, and weld profile—that a completed structural weld must satisfy to pass visual inspection under the Structural Welding Code–Steel.
Guided Face-Bend TestA mechanical test in which a groove weld coupon is bent around a fixed-radius die with the weld face in tension; the bent surface is then examined for cracks or other discontinuities exceeding code acceptance limits.
UndercutA groove melted into the base metal at the weld toe that is left unfilled by weld metal; AWS D1.1 limits its depth for structural applications.
Fillet Weld GaugeA precision measuring tool used to verify fillet weld leg size, throat dimension, and convexity or concavity, confirming compliance with the specified weld size.
ER70S-6An AWS A5.18-classified solid GMAW electrode wire; ER=electrode/rod, 70=minimum tensile strength of 70,000 psi deposited weld metal, S=solid wire, 6=chemical composition and deoxidizer level suitable for welding on mill-scale or slightly rusty plate.
C25 Shielding GasA common GMAW shielding gas blend of 75% argon and 25% carbon dioxide that provides good arc stability, moderate spatter, and adequate penetration for short-circuit and spray transfer on carbon steel.
Portfolio ReflectionA written self-assessment, typically one page, in which the welder identifies a specific skill deficiency, explains its root cause, and documents the corrective steps taken; it demonstrates professional accountability and learning growth.

Worked examples4

1. Your fillet weld gauge shows the measured weld leg on the 2F coupon is 5/16 inch. Your WPS specifies a minimum fillet weld size of 3/8 inch for ¼-inch base plate. Does this weld pass or fail AWS D1.1 visual inspection for weld size, and by how much is it undersize?
  1. Convert both dimensions to a common unit. 5/16 inch = 0.3125 inch (measured); 3/8 inch = 0.375 inch (required).
  2. Subtract measured from required: 0.375 − 0.3125 = 0.0625 inch.
  3. AWS D1.1 requires the fillet weld leg to meet or exceed the specified size. The measured leg is below the required minimum.
  4. Conclusion: the weld FAILS visual inspection; it is undersize by 0.0625 inch (1/16 inch). The coupon must be rejected; additional weld metal may be added to bring the leg up to size if the weld is otherwise sound, per your instructor's direction.
Answer: The weld fails. It is 1/16 inch (0.0625 inch) undersize.
2. Using a straight-edge fillet gauge, you measure the convexity of your 1F fillet weld. The weld leg size is 3/8 inch. AWS D1.1 limits convexity to 1/16 inch plus 0.10 times the weld leg size. What is the maximum allowable convexity for this weld?
  1. Identify the formula: Maximum convexity = 1/16 inch + (0.10 × leg size).
  2. Convert 1/16 inch to decimal: 1/16 = 0.0625 inch.
  3. Calculate 0.10 × 3/8 inch: 0.10 × 0.375 = 0.0375 inch.
  4. Add the two values: 0.0625 + 0.0375 = 0.1000 inch.
  5. Convert back to a fraction for practical use: 0.100 inch ≈ 3/32 inch (0.09375 inch) rounded up; express as 0.100 inch or just over 3/32 inch.
Answer: The maximum allowable convexity is 0.100 inch (just over 3/32 inch) for a 3/8-inch fillet weld leg.
3. You are setting up your CV GMAW machine for 0.035-inch ER70S-6 wire on ¼-inch A36 plate in the 1G position. Your WPS specifies a voltage range of 18–21 V and a wire feed speed range of 280–320 inches per minute (ipm). You set the machine to 19.5 V and 300 ipm. Are these settings within the WPS range?
  1. Check voltage: the WPS allows 18–21 V. Your setting is 19.5 V. 18 ≤ 19.5 ≤ 21 → within range.
  2. Check wire feed speed: the WPS allows 280–320 ipm. Your setting is 300 ipm. 280 ≤ 300 ≤ 320 → within range.
  3. Both parameters are within the WPS-specified ranges; the setup is compliant.
  4. Record 19.5 V and 300 ipm on your machine setup card before striking an arc.
Answer: Yes, both settings are within the WPS ranges. Record them on the machine setup card.
4. After your face-bend test on the 1G groove coupon, you find two separate open discontinuities on the convex (tension) surface. One measures 1/16 inch long and the other measures 3/16 inch long. AWS D1.1 allows individual discontinuities up to 1/8 inch (0.125 inch) on a bend specimen. Do these discontinuities cause the coupon to pass or fail?
  1. Convert all measurements to decimal inches: 1/16 inch = 0.0625 inch; 3/16 inch = 0.1875 inch; limit = 1/8 inch = 0.125 inch.
  2. Evaluate the first discontinuity: 0.0625 inch ≤ 0.125 inch → passes individually.
  3. Evaluate the second discontinuity: 0.1875 inch > 0.125 inch → exceeds the individual limit → FAILS.
  4. Because the second discontinuity exceeds the individual maximum allowed length, the coupon fails the bend test regardless of the first discontinuity's size.
Answer: The coupon fails the bend test. The 3/16-inch (0.1875-inch) discontinuity exceeds the 1/8-inch (0.125-inch) individual limit.

The math in this lesson2

Learners evaluate the convexity limit 1/16 in + 0.10 × leg and check legs and machine settings against WPS ranges.
A-SSE.1N-Q.3
Brush up in the math halls at newSchoolWorks.com:
In class: Independent performance weld session: with no coaching, each student selects their WPS, sets up the machine independently, tacks their coupons, and completes one each of 1F fillet, 2F fillet, 3F fillet, and 1G groove welds; instructor observes safety compliance only and does not advise on technique. · Portfolio assembly: students compile all lab log sheets, process logs, defect logs, bend test inspection reports, safety audit checklist, and machine setup cards from the course into a structured GMAW process portfolio with a table of contents and a one-page written reflection describing their most significant skill improvement. · Structured weld review presentation: each student presents their 1G groove weld coupon and one fillet weld coupon to the instructor, explaining WPS variables chosen, problems encountered and corrected, and self-inspection results; instructor asks three to five follow-up questions drawn from AWS D1.1 visual criteria and GMAW process knowledge.
Materials: CV/DC GMAW machine; ER70S-6 0.035" wire; C25 gas; ¼" A36 plate for fillet and groove coupons; all lab log and inspection forms from prior lessons; portfolio binder or digital folder; fillet weld gauge; guided-bend jig; angle grinder; AWS D1.1 reference; student-completed WPS set; printer or digital submission tool
Check: All four performance welds inspected by instructor against AWS D1.1 visual acceptance criteria using fillet weld gauge; 1G groove weld must also pass a face-bend test. Portfolio evaluated with a rubric: completeness (all required documents present), accuracy of self-inspection records, and quality of written reflection—must score 75% or higher. Verbal presentation must demonstrate correct use of AWS D1.1 terminology.

Practice check8

Answer each question, then check it. Nothing is recorded; this is your own practice.

AWS SENSE L1-2 – Professional Practices
1. During the independent performance weld session, the instructor's role is limited to:
NCCER Welding L1-4 – GMAW Process
2. Which GMAW position requires the welder to pay closest attention to preventing the molten puddle from sagging downward due to gravity while maintaining fusion on both legs?
AWS D1.1 Certified Welder – Visual Inspection
3. AWS D1.1 specifies that undercut depth on primary structural members shall not exceed:
AWS D1.1 Certified Welder – Mechanical Testing
4. A face-bend test is performed on the 1G groove weld coupon. The weld face is placed in tension during the bend. After bending, you find a crack that originates at the weld toe and measures 3/32 inch long. Given that the AWS D1.1 bend specimen limit is 1/8 inch for individual discontinuities, this coupon:
AWS SENSE L1-2 – GMAW Process Variables
5. Which shielding gas blend is specified for the capstone GMAW performance welds, and what is its composition?
NCCER Welding L1-4 – Professional Practices and Documentation
6. When preparing the portfolio, a student discovers that three lab log sheets from early in the course have missing voltage and wire feed speed entries. The most appropriate action is to:
AWS SENSE L1-2 – Filler Metal Classification
7. The AWS classification ER70S-6 describes a solid GMAW electrode wire. What does the '70' in this designation indicate?
AWS D1.1 Certified Welder – Professional Conduct
8. During the structured weld review presentation, a student cannot remember the AWS D1.1 limit for undercut depth when the instructor asks. The student should:
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