IIW IWP common mistakes
IIW IWP · Understand the traps and how to avoid them.
Treating the IIW IWP written paper as a recall test and answering process questions purely from workshop habit, quoting a rule of thumb (for example 'about 10 l/min for any MIG job') instead of the standard or code basis the question is asking for.
Most candidates come from a practical welding background and have learned by doing; they answer from experience without linking the answer to the underlying standard, recommended practice or code clause that the examiner is testing. The exam is a knowledge and understanding qualification, so an answer that is right in the workshop but unsupported in principle loses marks.
What to do instead
For every process question, practise giving the answer in three parts: the parameter or rule, the reason it is that value, and the source basis (standard, manufacturer data, code). Build a one-page summary per process (SMAW, GMAW, GTAW, FCAW, SAW) covering current ranges, gas flow, polarity, electrode classification and typical defects, and rehearse explaining each item, not just stating it.
Confusing the electrode classification systems across processes, for example reading an E7018 as a rutile electrode, mixing up E11018 with ER110S-G, or treating an F7A2-EM12K flux designation as if the first number were a tensile strength in ksi without checking the system.
The classification letters and numbers look similar across covered, tubular and solid electrodes but encode different things (tensile strength, position, coating or flux type, current type, shielding gas, impact energy). Candidates memorise a few codes and then pattern-match incorrectly under time pressure.
What to do instead
Learn each classification field by field with a worked example per system: for E7018 explain 70 = 70 ksi minimum tensile, 1 = all positions, 8 = low-hydrogen iron powder coating and the current/polarity implications; for ER70S-6 explain the S = solid wire and 6 = silicon/manganese level; for F7A2-EM12K explain the flux tensile/position/current/impact fields and the wire designation separately. Make a comparison table and test yourself by decoding random codes.
Explaining heat input, cooling rate and preheat only as rules to be quoted, without being able to show the calculation or connect the variables; for example saying 'preheat stops cracking' but not being able to compute heat input from voltage, current and travel speed or explain what changes when travel speed doubles.
These are the core concepts that link the materials and fabrication domains, and they are usually learned as isolated facts. Candidates can state the formula but not apply it, so they fail questions that ask for a calculation or a consequence.
What to do instead
Practise the heat input calculation (kJ/mm = voltage x current x 60 / (travel speed in mm/min x 1000)) with realistic numbers until it is automatic, then for each result state the effect on cooling rate, hardness, hydrogen escape and toughness. Link preheat to carbon equivalent and thickness, and rehearse a short chain of reasoning from material and thickness to preheat, heat input, and risk of cold cracking.
Treating carbon equivalent, hydrogen and restraint as separate facts and failing to combine them when diagnosing cold cracking; answers list 'hydrogen' as the cause and stop, without identifying the source of hydrogen, the restraint condition or the hard microstructure that together produced the crack.
Exam questions often present a cracking scenario and expect a structured cause analysis. Candidates who have memorised single causes give a single-cause answer and miss the marks for the interaction of composition, hydrogen level, restraint and cooling.
What to do instead
Use a fixed framework for every cracking or defect scenario: material and CE, hydrogen sources (electrode condition, moisture, surface contamination), restraint and joint design, thermal cycle and preheat/interpass, then the remedy. Practise writing two-sentence diagnoses that name the mechanism and the contributing factors, and check your answer against the framework before moving on.
Describing a joint or weld symbol from memory without reading it field by field, for example assuming the arrow side is the weld side, missing the tail reference or misreading a supplementary symbol such as all-around or field weld.
Drawing interpretation is often learned informally on the shop floor, and candidates answer from the general shape of the symbol rather than the standard's rules. Under exam conditions the arrow-side and other-side convention is a frequent error.
What to do instead
Work through the symbol standard systematically: reference line, arrow, arrow-side versus other-side position, size and length, pitch, tail, and supplementary symbols. Practise on a set of ten varied symbols, writing out each field in words, and always state the convention explicitly in your answer so the examiner can see the reasoning.
Giving a single generic weldability statement for a material ('stainless is easy to weld') without addressing the specific grade and its risks, such as sensitisation and carbide precipitation in austenitic stainless, hydrogen cracking in high-strength low-alloy steels, or porosity and loss of alloying elements in aluminium.
Weldability questions are often answered from broad workshop impressions. Candidates do not separate ferritic, austenitic, duplex and aluminium families, and do not connect each to the process, filler and consumable choice.
What to do instead
Build a material-by-risk matrix: for each family list the main defect risks, the mechanism, the process and consumable implications, and the controls (heat input limits, interpass temperature, preheat, shielding, cleaning). Rehearse one short answer per family that names the mechanism and the control, and always state the grade assumption you are making.
Answering NDT questions by describing what a method is rather than what it can and cannot detect; for example claiming ultrasonic testing will reliably find surface-breaking cracks, or that radiographic testing will detect lack of fusion oriented parallel to the beam.
Candidates learn method names and basic principles, then answer capability questions from intuition. The relationship between defect orientation, location and the physics of each method is the part that is examined and the part least practised.
What to do instead
For each method (VT, PT, MT, UT, RT) write the detection capability, the orientation and location limits, the surface preparation required and the typical standards basis. Practise scenario questions: given a defect type and location, choose the method and justify it in terms of the physics, and state what the method would miss.
Treating health and safety questions as common sense and giving a short answer such as 'wear PPE and ventilate the area', without identifying the specific hazard, the exposure route, the control hierarchy or the monitoring requirement.
Safety knowledge is often absorbed as habit rather than as a structured risk assessment. Candidates do not apply the hierarchy of control (elimination, substitution, engineering controls, administrative controls, PPE) and miss marks for fume extraction, confined space, electrical and fire risks specific to welding.
What to do instead
Practise answering safety questions with a fixed structure: hazard, exposure route, who is at risk, controls in hierarchy order, monitoring and emergency response. Prepare specific content for welding fume and extraction, confined spaces and gas testing, arc flash and electrical safety, fire and hot work permits, and noise and radiation, and apply the structure to each.
Describing practical welding technique in vague terms ('set the machine right', 'use a good angle') instead of giving measurable parameters: current, voltage, travel speed, gas flow, electrode angle, stick-out, root gap and land, and the visual acceptance criteria for the finished weld.
Practical competence is assessed through the ability to explain and justify technique. Candidates who weld well but have never articulated their settings give answers that cannot be marked, and they cannot connect a defect to the parameter that caused it.
What to do instead
For each process and joint type, write a parameter card with typical current and voltage ranges, polarity, gas and flow, travel speed, electrode angle, and root gap and land. Then rehearse defect-to-cause links (for example excess penetration to current or root gap, lack of fusion to travel speed or angle) and state the acceptance criteria you would apply.
Answering supervision and production questions as if the candidate were the welder, not the person responsible for planning, qualification, documentation and control; for example describing how to make the weld rather than how to verify that the welder and procedure are qualified and that records are in place.
The IWP role is supervisory, and candidates from a welding background default to the operative perspective. They omit the planning and control elements: WPS and PQR, welder qualification and its scope, traceability, inspection and test plans, and progress and resource control.
What to do instead
Reframe every supervision question around the control loop: what is required (specification and standard), what evidence shows it is met (WPS, PQR, welder certificates, records), what could go wrong (deviation, rework, non-conformance), and what action the supervisor takes. Practise writing answers from that perspective and check that each answer names the document, the check and the action.