AWS D1.1 / D1.2 & ABS/USCG Performance Qualification Rehearsal

AWS D1.1 / D1.2 & ABS/USCG Performance Qualification Rehearsal

This lab session is your dress rehearsal. Every weld you lay down today follows the same sequence, documentation, and acceptance criteria you will face on your actual certification exams. Treat every coupon as if a third-party inspector is standing at your shoulder — because on exam day, one will be.

Why Performance Qualification Matters

AWS D1.1 (structural steel) and D1.2 (aluminum) are performance standards: you do not pass by answering questions on paper — you pass by producing a weld that survives visual inspection and destructive bend testing. ABS/USCG qualification works the same way. The credential lives or dies on the coupon you hand to the inspector. Rehearsing the full sequence — setup, execution, inspection, documentation — eliminates surprises and builds the muscle memory that test-day nerves can erase.

Pre-Weld Checks: The Foundation of a Passing Coupon

Before you strike an arc, complete every pre-weld step. Skipping one is the most common reason a coupon fails before welding even begins.

Joint fitup and dimensions. Verify root opening, bevel angle, and land dimension against the Weld Procedure Specification (WPS) you are qualifying to. Use a weld gauge — not your eye. Record the measurements.

Mill scale and oxide removal. On carbon steel, grind or flap-disc the joint faces and a minimum of 1 inch back from the joint edge to bare bright metal. Mill scale traps porosity. On aluminum 6061-T6, use only a dedicated stainless steel wire brush — never one that has touched steel — to remove the aluminum oxide layer immediately before welding. Oxide contamination is the primary cause of porosity and lack-of-fusion failures on aluminum coupons.

Low-hydrogen electrode control. If you are welding with E7018 for the D1.1 or ABS steel coupon, electrodes must come from a rod oven or sealed container. Exposed low-hydrogen electrodes absorb moisture and produce hydrogen-induced cracking — an automatic failure on any bend test.

Preheat. Consult the WPS. Most test coupons on mild carbon steel at typical thicknesses do not require preheat, but verify. Use temp-sticks or a contact thermometer; do not guess.

Welding in Position: 3G and 4G Discipline

3G (vertical) and 4G (overhead) groove welds are the positions most commonly required for AWS and ABS qualification because qualifying in them extends your certification range. In the vertical position, control travel speed carefully: moving too fast thins the bead and risks incomplete fusion at the toes; moving too slow creates excessive convexity and traps slag.

For each pass, maintain consistent arc length (approximately equal to the electrode diameter for SMAW), watch your work angle and travel angle, and let the puddle lead — do not push. On overhead, gravity pulls molten metal toward your face: increase travel speed slightly, keep the puddle small, and trust your PPE.

Interpass temperature. Between passes, check interpass temperature with a temp-stick. Exceeding the maximum interpass temperature listed on the WPS softens the heat-affected zone and can cause distortion or cracking. Allow the coupon to cool to within limits before depositing the next pass.

Interpass cleaning. Chip and wire-brush every pass before depositing the next. Any slag inclusion found in the bend test is a failure. On aluminum GMAW, there is no slag, but wipe spatter and inspect the bead surface for porosity before continuing.

Visual Inspection: Reading the Code Acceptance Criteria

Open AWS D1.1 or D1.2 to the visual acceptance criteria table before you inspect — not after. Key D1.1 visual acceptance criteria for welder qualification test coupons include:

• No cracks of any length.
• Complete fusion at toes and between passes.
• Undercut shall not exceed 1/32 inch (approximately 0.8 mm) in depth for the permitted locations.
• Weld reinforcement must be within the limits specified in the applicable table for the thickness being welded.
• Crater cracks are not permitted; fill all craters before extinguishing the arc.

For D1.2 aluminum, similar criteria apply with additional attention to porosity limits, since aluminum is far more susceptible to gas porosity than carbon steel.

For ABS/USCG simulation, inspect against the ABS Rules for Materials and Welding acceptance criteria. ABS criteria align closely with AWS criteria for visual inspection but are applied by a classification-society surveyor whose acceptance is required for the work to be stamped.

Guided Bend Test Rehearsal

The guided-bend fixture bends your coupon around a die of specified radius. Face bends load the weld crown in tension; root bends load the root in tension. After bending, inspect the convex surface for open discontinuities. Under D1.1, no single open discontinuity greater than 1/8 inch (3 mm) measured in any direction is acceptable. Corner cracks originating at specimen edges are generally disregarded. If your coupon opens up, examine the fracture: porosity, lack of fusion, and slag inclusions each leave a characteristic signature. Identify the cause before you re-weld.

ABS/USCG Simulation Protocol

For the ABS simulation, you will weld to a WPS provided by the instructor. Fill out the WPS compliance log as you weld, recording amperage, voltage, travel speed, electrode/wire classification, shielding gas, interpass temperature, and pass sequence. This documentation habit is not optional on commercial shipyard work — the log travels with the weld record.

Safety in This Lab

Lockout/tagout (LOTO): Before any adjustment to welding machines or the bend-test fixture, follow the facility LOTO procedure. Verify zero energy before touching internal components.

PPE: Auto-darkening helmet meeting ANSI Z87.1, shade appropriate to the process (typically shade 10–13 for SMAW/GMAW at qualification amperages), FR sleeves, leather welding gloves, and steel-toed boots are mandatory at all times on the floor. For overhead (4G) welding, add a leather cap and ensure no gaps at collar and cuffs — molten spatter will find any opening.

Fume extraction: Aluminum welding produces ozone and metal fume; ensure local exhaust ventilation is active and positioned correctly before beginning D1.2 coupons.

Hot coupon handling: Coupons remain dangerously hot long after welding. Mark them with soapstone, use pliers or tongs, and place them on a firebrick — never on a rubber mat or near combustibles.

The Re-Weld Rule

Any coupon that fails visual inspection or the guided bend rehearsal must be analyzed before you pick up a stinger again. Write down the defect, its probable cause, and the technique change you will make. Weld the replacement coupon only after the instructor reviews your analysis. This process is not a penalty — it is exactly what good welders do every day.