Conservation of "Rosie's Drill" and the Women Who Built an Aviation Legacy

As part of the Museum’s ongoing renovation, Museum conservators studied and treated an electric drill with associated artifacts for display in the upcoming Jay I. Kislak World War II in the Air gallery. Emblematic of the tools in use by women on the aircraft assembly lines during World War II, this artifact was owned and operated by Helen Nelson Brinkley and is nicknamed “Rosie’s Drill” after the iconic Rosie the Riveter likeness. The drill will be presented next to other artifacts from the B-17 factories and attests to a time when women were encouraged to fill out the wartime labor forces, supplying and maintaining their own tools.

History

After the attack on Pearl Harbor in 1941, Brinkley moved with her family to Everett, Washington, to find work, eventually becoming employed at a Boeing B-17 factory. She started working as an aluminum-skin riveter at the factory but then progressed to installing B-17 gun turrets.

According to a 1943 story about women aviation workers published in LIFE magazine, in 1941 only one percent of aviation employees were women; but by 1943, they comprised an estimated 65 percent of the aviation workforce, making a critical and sustained contribution to the American war effort. The Museum collected Brinkley's tools to represent these important social and cultural facets of aviation, and the drill maintains evidence of its original use in the form of splashes of paint, taped repairs, deposits of aged lubricant, dripped solder, and ingrained soiling. Evidence of an object's history of use is an important part of its historical significance, value, and impact, to be delicately maintained while harmful contaminants are cleaned from the artifact.

Condition

The drill arrived in the Emil Buehler Conservation Laboratory in very fragile condition, and the dramatic degradation pattern observed throughout the embrittled rubber cord required study before treatment and display decisions could be made. The rubber was friable, inflexible, scaling, and exfoliating in areas, and softened and gummy in others. This is typical of aged synthetic rubber that is undergoing age-related deterioration, including component migration, cross-linking, chain scission, oxidation, and other complex chemical changes. The sticky segments had attracted dust and debris from housing materials in storage, and the cord had been stored in a tangled position. Where the rubber hardened in place, it stuck to itself and to the drill body, and these hardened areas prevented the cord from being easily manipulated or straightened.

Analysis

Technical study and analysis employed photography; x-radiography; microchemical testing; microscopy; and spectroscopy, including Fourier-transfer infrared spectroscopy, attenuated total reflectance (FTIR–ATR) and x-ray fluorescence (XRF) spectroscopy. Polarized Light Microscopy (PLM), Phase Contrast Microscopy (PCM), and Transmission Electron Microscopy (TEM) were also performed by an outside laboratory to confirm that there was no insulating asbestos present within the electrical cord before it could be safely treated.

Spectroscopy of tiny samples of black elastomer identified it as a polyisoprene rubber, a synthetic latex. Sulfur (S) and zinc (Zn), elements identified in the bulk rubber are likely related to vulcanizing or to condensing and curing activation of the rubber, respectively. A patent review revealed that the technology to produce such a synthetic rubber was in established manufacturing use prior to the outbreak of WWII. The drill itself had been manufactured by Black & Decker after August 19, 1941.

Treatment

Treatment of the drill required initial untangling of the cord and removing unoriginal materials such as horsehair, plant material, dust, and corrosion without dislodging the surface scales of the embrittled rubber. The interior condition of the gear box was evaluated using x-radiography, and the exterior surface corrosion of the iron, copper, and aluminum alloys was removed to leave a stable surface patina.

Next a system for consolidating the rubber cord was devised with the goal of preventing surface loss, returning some flexibility to the material, supporting splits and mud-cracking, and aesthetically compensating for the uneven surface appearance and scattered losses. The chosen consolidant needed to be flexible, adherent, stable, and retreatable with low polarity solvents. Very few conservation-grade adhesives have all of these properties vis-à-vis the rubber cord material in question, and only one—an EVA co-polymer with high vinyl acetate content—had the flexibility, adherence properties, and solubility parameters required.

The use of the particular consolidant has been attested to in a handful of conservation and conservation-science studies, and it was evaluated at the Museum using mock-up materials, microchemical study, and pull testing prior to applications in two modes: Delivered precisely with syringes, the polymer both penetrated into the fine mud-cracking of the surface and bridged the gaps between the splits and cracks when built up in layers, returning flexibility to the overall cord structure without saturating the matte surface. When applied as a bandage over a Japanese-tissue carrier, the resin supported breaks and visually integrated the surface. The final appearance of the tissue bandages was modified with the addition of mattifying agents and pigments.

Conclusion

The drill cord is now stabilized and can be carefully manipulated into place for mounting and exhibition in the upcoming gallery. Unstable corrosion has been removed from the metal chuck and drill body while leaving intact a stable, gray patina as well as use-related deposits of lubricant, paint, and tape. Although they still show their age and history of use, the cord and metal surfaces now have a cleaner and more uniform and cared-for appearance overall.

After a long process of research, examination, analysis, testing, and treatment, this meticulously conserved artifact will take its place with other B-17 factory tools in the newly reimagined World War II gallery to represent the barrier-breaking resilience of the women on the aircraft assembly lines during a time of global crisis. The restoration of "Rosie's Drill" not only preserves a physical artifact but celebrates the stories of the women who played essential roles in the American war effort, reshaping the workforce and, ultimately, the course of history. We hope that the display of this artifact will help the public better appreciate the critical contributions made by women like Helen Nelson Brinkley, whose legacy of resilience, empowerment, and unwavering commitment continues to inspire us today.