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Activity 001: Weld Inspection & Quality Assessment Lab

Activity ID: U6M4-ACT-001 Duration: 40 minutes Objective: Students will perform visual inspection and dimensional measurement on a set of weld samples, applying acceptance criteria to make pass/fail decisions on each. Group Size: 2-3 students

Overview

Using a collection of MIG and TIG weld samples with varying quality levels, students will practice the systematic inspection procedure, measure critical dimensions, and document their findings. This develops the critical eye needed for self-assessment during future welding.

Materials & Equipment Needed

  • 10 weld samples (prepared by instructor or collected from student work):
  • 3 fillet welds on T-joints (varying quality: good, undersized, cold lap)
  • 3 butt welds (varying quality: good, excessive reinforcement, undercut)
  • 2 MIG beads (one good, one with porosity)
  • 2 TIG beads (one good, one with inconsistent dipping)
  • Fillet weld gauge set
  • Digital calipers
  • 10× magnifying loupe
  • LED flashlight
  • Welding inspection checklist forms (10 copies)
  • Acceptance criteria reference sheet (from Slide 001)
  • Scoring rubric
  • PPE: Safety glasses, leather gloves (sharp edges on samples)

Instructions & Procedure

Phase 1: Instruction & Calibration (8 minutes) 1. Instructor demonstrates the 7-step visual inspection procedure on one sample 2. Instructor demonstrates fillet gauge use — measuring leg size, checking profile 3. Students practice with the fillet gauge on the instructor's sample 4. Review the acceptance criteria reference sheet

Phase 2: Independent Inspection (22 minutes) Each group inspects all 10 samples. For each sample, complete the inspection form:

  1. Sample identification: Label (A through J), process (MIG or TIG), joint type
  2. Visual inspection:
  3. Overall appearance (1-5 scale)
  4. Bead width consistency: " min to " max
  5. Ripple/pattern consistency: even / uneven
  6. Visible defects: list each one found
  7. Dimensional measurement:
  8. Fillet welds: leg size " (left), " (right), profile shape
  9. Butt welds: reinforcement height ", width "
  10. Defect assessment (for each defect found):
  11. Type of defect
  12. Location on the weld
  13. Approximate size/severity
  14. Probable cause
  15. Pass/Fail decision: Based on acceptance criteria
  16. Justification: 1-2 sentences explaining the decision

Phase 3: Group Comparison & Instructor Review (10 minutes) 1. Groups compare their pass/fail decisions — did all groups agree? 2. Discuss any samples where groups disagreed — what criteria caused the split? 3. Instructor reveals the "correct" assessment for each sample 4. Discuss the most commonly missed defects 5. Instructor demonstrates a bend test on one fillet weld sample (if applicable) to show how internal defects are revealed

Discussion Points

  • Which defect was hardest to see? What inspection technique revealed it?
  • Did any sample look good at first glance but fail on closer inspection?
  • How would you apply this inspection skill to your own welds during practice?
  • What is the difference between "acceptable for a makerspace project" and "acceptable for structural work"?

Expected Outcomes

  • Students correctly apply the 7-step inspection procedure to all samples
  • Students achieve ≥80% agreement with the instructor's pass/fail assessments
  • Students can accurately measure fillet leg size within ±1/32"
  • Students identify at least 7 of 10 present defects

Assessment Rubric

Criteria Excellent (4) Proficient (3) Developing (2) Beginning (1)
Inspection Procedure Follows all 7 steps systematically Follows most steps Skips steps or inspects randomly No systematic approach
Measurement Accuracy Within ±1/32" of instructor values Within ±1/16" Within ±⅛" Cannot use gauge accurately
Defect Detection Finds ≥90% of present defects Finds 70-89% Finds 50-69% Finds <50%
Pass/Fail Decisions ≥90% match instructor assessment 70-89% match 50-69% match <50% match

Safety Considerations

  • Weld samples may have sharp edges, spatter, and slag — wear leather gloves and safety glasses
  • Do not attempt to break or bend samples without instructor supervision
  • If a sample has a crack, handle carefully — the crack may propagate during handling
  • This is an inspection activity — no welding or grinding unless specifically instructed

Last Updated: 2026-03-19