ROOT CAUSE ANALYSIS REPORT
LAG-RCA-001 Rev.D1
Executive Summary
This report presents a technical analysis of a manufacturing defect observed in a Lag T177J12CE (Tramontane 177 Series) 12-string acoustic guitar manufactured at the Lag Tianjin factory in December 2021 and sold by a Montreal music retailer in March 2026 — an interval of four years and three months between manufacture and point of sale. Three days after purchase, gaps were measured between the crown of every fret and the fretboard surface across all 20 frets. The gaps ranged from 0.004" to 0.008", were zero at both ends of each fret, and reached their maximum at or near the fret center. This distribution — consistent across all 20 frets in a graduated pattern that maps cleanly onto fret position — is the subject of the analysis.
The fretboard of this instrument is Brown Brankowood, a resin-impregnated compressed wood product manufactured by Green Wall Technology Co Ltd of Jiangsu province, China, and marketed by Lag Guitars since 2015 as a dimensionally stable, ecologically responsible alternative to Indian rosewood and ebony. The material's central claimed property — constant 5% moisture content, resistant to changes in humidity and temperature — is directly relevant to the observed defect, because the gap pattern is entirely inconsistent with a dimensionally inert fretboard and entirely consistent with the lateral shrinkage of a conventionally hygroscopic one.
The most credible hypothesis advanced in this report is that the Brankowood fretboard in this instrument did not achieve complete resin cure during manufacture, causing it to behave hygroscopically. The guitar was manufactured in December 2021 — at the height of the pandemic-driven guitar industry demand surge, and during China's zero-COVID operational disruptions, which affected both the Lag Tianjin factory and the Green Wall Technology production facility in Jiangsu province simultaneously. The conditions most likely to compromise a chemically precise multi-stage stabilization process were present at both ends of the Brankowood supply chain at the same time.
Two scenarios are identified, as the physical evidence alone cannot determine which applies.
Under the first, Lag maintained its pre-Brankowood humidity and quality controls, and the defective material passed through by statistical chance — possible, but the less probable explanation.
Under the second, those controls were possibly relaxed upon adopting Brankowood, on the rational but ultimately incorrect assumption that a dimensionally stable fretboard made them unnecessary. This would have created a quality assurance blind spot in which a partially stabilized fretboard passed factory inspection undetected, with the problem remaining latent and invisible until the slow process of fretboard equilibration ran its course over months or years in a lower-humidity environment.
The fact that the defect passed through to the finished instrument makes the second scenario the more probable of the two.
The distinction between these scenarios is fundamentally one of risk analysis, and it has direct implications for the distribution of responsibility among Lag, Green Wall Technology, and the distribution chain. If Green Wall Technology represented the material as consistently and fully stabilized without qualification, and that representation did not accurately reflect the actual variability of their production process, a significant portion of responsibility for the potential quality assurance blind spot lies with the supplier. This question cannot be resolved without access to the commercial communications between the parties.
The damage mechanism is time-dependent and cumulative. A guitar of identical materials and manufacture, sold one year after production rather than four, might well have shown no measurable gaps at point of sale — not because the mechanism was absent, but because insufficient time had elapsed for the cumulative shrinkage to lift the frets visibly. A clean inspection at point of sale is therefore not a clean bill of health for an instrument whose fretboard may be behaving hygroscopically. This has direct implications for three groups: prospective purchasers, who should be aware of these risks before purchase; recent purchasers, whose instruments may develop fret or structural issues over time even if they appeared sound at point of sale; and existing owners who have already experienced such problems and may have been told — or assumed — that the cause was inadequate humidity management on their part. For this last group, the analysis presented here suggests that the root cause may lie in the manufacturing process rather than in the owner's care of the instrument.
Beyond the fret seating issue, the analysis identifies a structural concern at the fretboard-neck glue joint. The Khaya neck shaft is hygroscopically active while the Brankowood fretboard is not — or is less so. Any reduction in ambient humidity from the factory conditions at which the joint was glued imposes lateral shear stress along the full length of the joint. Quantitative analysis indicates that at 30% RH — a reasonable winter target for a humidified Montreal home — this stress approaches or exceeds the tensile strength of the Khaya perpendicular to grain and the peel strength of the glue joint at its edges. In an unhumidified home the risk is substantially greater. This concern applies to any Lag guitar combining a Brankowood fretboard with a natural-wood neck shaft, regardless of production period.
The report makes the following recommendations to Lag, detailed in Appendix C: re-establish the fretboard-specific humidity and quality controls that the adoption of Brankowood may have led the factory to set aside; establish a batch-level incoming verification program for Brankowood stock, calibrated to the material's actual performance uncertainty rather than its claimed properties; review the commercial communications with Green Wall Technology regarding performance specifications and limitations; conduct a targeted review of the 2020-2022 production cohort, which represents the highest-risk period within the Lag Brankowood range; and establish a formal long-term performance monitoring mechanism to collect and act on field data from warranty and repair records.
The Brankowood initiative reflects a genuine and commendable commitment to the sustainability of the guitar industry. The recommendations in this report are offered in that spirit — not as an indictment of the initiative, but as measures necessary to ensure that its long-term success is founded on verified performance rather than assumed performance.