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newSchoolWorks.com › VoTechWorks › Manufacturing & Marine › Shipbuilding / Marine Fabrication › Steel & Aluminum Welding for Marine Fabrication › Lesson 12
MFG-SHIP13-03 · Lesson 12 · 23 clock hours · lab

Integrated Welding Project: Marine Panel Assembly with Full QA Documentation

Objective. Students will independently plan, fabricate, and inspect a multi-material marine panel assembly (carbon steel frame with aluminum insert or deck fitting) using at least two welding processes, completing all production, inspection, and QA documentation to shipyard standards.

Integrated Welding Project: Marine Panel Assembly with Full QA Documentation

This lab brings together every skill you have built in this course. You will plan, fabricate, and inspect a real marine panel assembly — a carbon steel frame joined to an aluminum insert or deck fitting — using at least two welding processes and completing the same QA paperwork a production shipyard requires. Nothing leaves the floor without documentation.

Why This Matters

Shipyards, classification societies, and the U.S. Coast Guard do not accept welds on faith. Every weld on a regulated vessel must be traceable: who welded it, with what process and consumables, at what parameters, and whether it passed inspection. When you submit your QA package at the end of this project, you are practicing the exact workflow required for ABS and USCG acceptance. Employers at naval and commercial yards expect new hires to understand this system from day one.

Pre-Production Planning

Before you strike an arc, write your welding plan. A good plan identifies:

Your instructor must approve your written plan before fabrication begins. This is not a formality — it is the shipyard gate-check that prevents costly mistakes.

Panel Fabrication

Work methodically across multiple sessions. Log every entry in your production traveler as you go — do not reconstruct it from memory at the end.

Steel frame (SMAW or FCAW): Tack in opposing corners first. Check squareness with a framing square before laying full welds. Monitor and record interpass temperature with your contact thermometer; most carbon steel WPS documents set a maximum interpass temperature, commonly around 400 °F — confirm the limit on your WPS. Exceed it and you risk degrading toughness in the heat-affected zone.

Aluminum insert/fitting (GMAW or GTAW): Clean all aluminum surfaces immediately before welding — use a dedicated stainless steel wire brush and then wipe with an approved solvent. Oxide contamination causes porosity. Do not allow the aluminum and steel to form a direct weld fusion joint; design a mechanical or bolted transition detail, or use a purpose-designed bimetallic insert if specified. Record wire feed speed, voltage, travel speed, and shielding gas flow rate in your traveler for every weld pass.

Non-conformances: If you detect a defect during production — excessive spatter, a visible crack, undercut beyond limits — stop, document it in the non-conformance section of your traveler with a description and your corrective action, then repair before continuing.

Safety Checkpoints

Final Inspection and QA Package

Visual Testing (VT) is the first and most fundamental NDE method and the one you will perform. Using your fillet gauge, undercut gauge, and 10x magnifier, inspect every weld against the acceptance criteria in AWS D1.1 (structural steel) and AWS D1.2 (aluminum). Common rejectable discontinuities include: cracks (any length), incomplete fusion, undercut exceeding the allowable limit, porosity clusters beyond the code limit, and weld size less than specified.

Complete the ABS-style inspection report for each weld joint: record joint ID, process, acceptance or rejection, and disposition. Photograph and annotate four critical weld zones — label each photo with joint ID, view direction, and the feature being shown.

Assemble your full QA package in order: welding plan, production traveler, inspection report, annotated photos. This package is your deliverable — treat it as you would a document leaving the shipyard for a classification surveyor.

Grading

Your QA package is graded on four equal categories: fabrication quality, visual inspection accuracy, documentation completeness, and distortion control. You need 70% overall with no single category below 60%. Any panel with unrepaired rejectable defects is returned to you for correction before final grading. Correction and resubmission is the professional standard — it is not a penalty, it is how shipyards work.

Key terms10

Production TravelerA document that follows a weldment through fabrication, recording parameters, interpass temperatures, non-conformances, and corrective actions for every weld pass; it provides full traceability required by classification societies.
Welding Procedure Specification (WPS)A written document that prescribes the variables — process, filler, preheat, interpass temperature, current, voltage, travel speed — within which a qualified weld must be produced to meet a given standard.
Interpass TemperatureThe temperature of the base metal in the weld joint area measured between weld passes; controlling it prevents degradation of the heat-affected zone and helps limit distortion.
Visual Testing (VT)The examination of a weld by eye, with or without a magnifier and gauges, against acceptance criteria in the applicable code; it is the first NDE method applied to any weld.
AWS D1.1The American Welding Society's Structural Welding Code for steel, which sets acceptance criteria for weld profile, discontinuities, and testing on structural steel weldments.
AWS D1.2The American Welding Society's Structural Welding Code for aluminum, which sets acceptance criteria for weld profile, discontinuities, and testing on aluminum structural weldments.
Non-ConformanceAny condition in a weldment that fails to meet the requirements of the applicable code, WPS, or drawing; it must be documented, dispositioned, and resolved before the part advances.
Bimetallic InsertA transition piece engineered to join dissimilar metals such as steel and aluminum without creating a direct fusion bond between them, avoiding brittle intermetallic compounds and galvanic corrosion.
Weld SequenceThe planned order in which welds are deposited in an assembly, chosen to balance heat input and minimize residual stress and distortion in the finished weldment.
ABS Inspection ReportA standardized form used by American Bureau of Shipping surveyors and shipyard QA personnel to record the results of weld inspection on marine structures, providing the documentation trail required for vessel classification.

Worked examples4

1. Your fillet weld drawing calls for a 5/16 in (0.3125 in) fillet leg. You measure the actual weld with a fillet gauge and read 0.250 in on one leg. AWS D1.1 tolerance for fillet weld size allows the weld to be under the specified size by no more than 1/16 in (0.0625 in). Is this weld acceptable?
  1. Step 1 — Determine the minimum acceptable fillet leg size: Minimum = Specified size − Maximum underrun = 0.3125 in − 0.0625 in = 0.250 in.
  2. Step 2 — Compare the measured value to the minimum: Measured = 0.250 in; Minimum = 0.250 in.
  3. Step 3 — Determine acceptability: 0.250 in equals the minimum exactly, which meets the tolerance limit.
Answer: The weld is acceptable — it is exactly at the minimum allowable size. Any measurement below 0.250 in would be rejectable and require repair.
2. Your WPS specifies a maximum interpass temperature of 400 °F for the carbon steel frame. After completing a pass, your contact thermometer reads 275 °F. How many degrees of cooling margin do you have before you must wait, and is it safe to weld the next pass?
  1. Step 1 — Identify the limit and the current reading: Maximum interpass = 400 °F; Current temperature = 275 °F.
  2. Step 2 — Calculate the margin: Margin = 400 °F − 275 °F = 125 °F.
  3. Step 3 — Assess readiness: 275 °F is below 400 °F, so you have 125 °F of margin remaining. The next pass may proceed without waiting.
Answer: You have 125 °F of margin. It is safe to weld the next pass immediately because the interpass temperature is below the WPS maximum.
3. You are documenting weld zones for your QA photo set. Your panel has four labeled joints: J-1 (steel frame corner), J-2 (steel-to-steel T-joint), J-3 (aluminum insert edge weld), and J-4 (aluminum fitting). The assignment requires exactly four annotated photos of 'critical weld zones.' You have taken two photos so far (J-1 and J-3). How many more photos do you need, and which joints should they cover?
  1. Step 1 — Determine total photos required: 4 critical weld zone photos required.
  2. Step 2 — Determine photos already taken: 2 photos taken (J-1, J-3).
  3. Step 3 — Calculate remaining photos needed: 4 − 2 = 2 more photos needed.
  4. Step 4 — Identify remaining joints not yet photographed: J-2 and J-4 have not been photographed.
Answer: You need 2 more photos, covering joints J-2 and J-4, to complete the required set of four annotated critical weld zone photographs.
4. Your cutlist calls for three pieces of 3/8 in carbon steel plate, each 12 in × 6 in, and two pieces of 5083 aluminum plate, each 6 in × 6 in. You are cutting from a single 24 in × 24 in sheet of steel plate and a single 12 in × 12 in sheet of aluminum. Do you have enough material on each sheet?
  1. Step 1 — Calculate the area required for steel: Each steel piece = 12 in × 6 in = 72 sq in; Three pieces = 3 × 72 = 216 sq in.
  2. Step 2 — Calculate the area of the steel sheet: 24 in × 24 in = 576 sq in. Since 216 sq in < 576 sq in, the steel sheet is sufficient.
  3. Step 3 — Calculate the area required for aluminum: Each aluminum piece = 6 in × 6 in = 36 sq in; Two pieces = 2 × 36 = 72 sq in.
  4. Step 4 — Calculate the area of the aluminum sheet: 12 in × 12 in = 144 sq in. Since 72 sq in < 144 sq in, the aluminum sheet is sufficient.
Answer: Yes — you have enough material on both sheets. The steel pieces require 216 sq in from a 576 sq in sheet; the aluminum pieces require 72 sq in from a 144 sq in sheet. Note that nesting efficiency and saw kerf will consume some material, so always confirm your layout before cutting.

The math in this lesson2

Learners total plate area for a cut list of steel and aluminum pieces.
7.G.6N-Q.3
Brush up in the math halls at newSchoolWorks.com:
In class: Pre-production planning: each student writes a brief welding plan identifying joint types, process and filler selections, weld sequence to minimize distortion, required PPE and ventilation, and a materials cutlist; plan is reviewed by the instructor and approved before fabrication begins. · Panel fabrication: students fabricate the assembly over multiple work sessions using SMAW or FCAW for the steel frame and GMAW or GTAW for the aluminum insert/fitting, logging all interpass temperatures, parameter settings, and any non-conformances in a production traveler document. · Final inspection and QA package: students perform a complete VT of the finished assembly using gauges and the AWS D1.1/D1.2 criteria, complete an ABS-style inspection report, photograph and annotate four critical weld zones, and submit the full QA package (plan, traveler, inspection report, photos) for instructor grading.
Materials: Assorted carbon steel plate and structural shapes (3/8 and 1/2 inch), 5083 or 6061 aluminum plate and extrusions, SMAW/FCAW/GMAW/GTAW equipment as selected, full consumables per WPS, contact thermometer, fillet and undercut gauges, 10x magnifier, digital camera or phone, ABS inspection report forms, production traveler template, AWS D1.1 and D1.2 visual acceptance criteria cards, PPE
Check: QA package graded on a four-category rubric (fabrication quality, visual inspection accuracy, documentation completeness, distortion control); students must achieve 70% overall with no category below 60%. Panels with rejectable unrepaired weld defects are returned for correction before final grading.

Practice check8

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

NCCER Shipfitting — Production Planning
1. Before fabrication begins on your marine panel assembly, which document must be approved by your instructor?
AWS D1.2 Aluminum / NCCER Maritime Welding
2. Which of the following is the primary reason that aluminum surfaces must be cleaned with a dedicated stainless steel wire brush and solvent immediately before GMAW or GTAW?
AWS D1.1 Certified Welder — Visual Inspection
3. A fillet weld is specified at 3/8 in. Your gauge measures the deposited weld at 5/16 in on one side. Under AWS D1.1, the maximum allowable underrun for a fillet weld is 1/16 in. What is the correct disposition?
NCCER Maritime Welding — Material Preparation and Safety
4. When welding a carbon steel frame adjacent to an aluminum insert, which hazard requires you to select separate wire brushes and never use a brush on both metals?
ABS/USCG Weld Test — QA Documentation
5. The production traveler serves which primary function in a shipyard QA system?
AWS D1.1 / AWS D1.2 — Visual Acceptance Criteria
6. Which of the following weld discontinuities is rejectable under both AWS D1.1 and AWS D1.2, regardless of length?
NCCER Maritime Welding — Safety and Hazard Control
7. What is the correct safety procedure before changing the wire spool on a GMAW machine or clearing a wire feed jam?
NCCER Shipfitting — Distortion Control and Weld Sequencing
8. You are sequencing fillet welds on a rectangular steel frame to minimize distortion. Which approach best achieves this goal?
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