The Experienced Welder Who Won't Follow the WPS
A fabricator employs a welder with 22 years of experience who is widely regarded as the shop's best. He is qualified for the process and thickness on a current project requiring CJP groove welds in 3/4-inch plate with a specified preheat of 200°F and interpass limit of 450°F. During a walk-through, the QC inspector observes him welding without a preheat check and without a temperature stick or pyrometer at the joint. When asked, the welder says he has 'welded this thickness for two decades' and 'never had a weld fail.' The weld in progress is on a member scheduled for delivery in 5 days. The shop foreman is the welder's brother-in-law and has told the QC inspector to 'leave him alone, he knows what he's doing.' The QC inspector's written authority allows him to reject nonconforming work but does not explicitly address stopping a welder mid-pass.
1. Analyze the experience-versus-procedure conflict and the organizational dynamics at play.
Read the worked answer
Experience is valuable but it does not substitute for the WPS. Preheat and interpass limits are specified for metallurgical reasons - hydrogen control and toughness - that are not visible in a finished weld and may not show up for years. A welder who has 'never had a weld fail' has not necessarily inspected for the failure modes preheat prevents.
The organizational problem is as serious as the technical one. The foreman's relationship to the welder and his instruction to the QC inspector compromise the independence of the quality function. The QC inspector's authority is also underspecified: rejecting nonconforming work after the fact is weaker than stopping nonconforming work in progress.
The QC inspector should not accept the foreman's instruction. He should escalate to the QC manager, document the observation (time, joint, welder, absence of preheat measurement), and require the weld in progress to be evaluated. The welder's experience should be respected in tone but not in substance: the requirement is the same for everyone.
2. What should the QC inspector do about the weld in progress and the 5-day delivery, and what procedural change should follow?
Read the worked answer
For the weld in progress: stop the pass, measure preheat at the joint, and record the result. If preheat is below 200°F, the weld is nonconforming and must be evaluated - likely removed and re-welded under controlled preheat. If preheat is within range by measurement, document it and allow completion with ongoing interpass checks. The 5-day delivery does not change the acceptance criteria; a rejected weld costs more than a day's delay.
For the procedural change: the QC inspector's authority should be amended to explicitly include stop-work on nonconforming in-process work, and the escalation path should bypass the foreman when the foreman has a conflict of interest. The shop should also require preheat and interpass records at each CJP joint so compliance is documented rather than assumed. Finally, the foreman's instruction should be addressed by management - a quality function that can be overridden by a family relationship is not a quality function.