For the past few years, the National Air and Space Museum’s Conservation Unit has been undertaking treatment of objects scheduled to be displayed in the newly renovated galleries as part of a major renovation of the Washington, DC, Museum. It is always fascinating to see what project or adventure will turn up next when working in the conservation ab. Recently an old trophy consisting of a cylindrical wooden base with a standing figure of the Roman god Mercury on top was brought into the lab. The figure is holding a small model of an airplane in an outstretched hand. I knew that its conservation treatment was going to pose an interesting technical challenge because the joint securing the figure to the base of the trophy had been broken and several other issues seemed to be evident.
At the beginning of each conservation assessment, the object is photographed and examined, and the curator is consulted to determine the next step. During the documentation process, and in consult with curator Carolyn Russo, I learned that the trophy had an interesting, and bittersweet history. This trophy was originally prepared by the Lockheed Aircraft Corporation with plans to present it to Amelia Earhart when she returned from her 1937 around-the-world flight. The trophy features a figure of the Roman god Mercury holding a miniature of Earhart’s plane, the Lockheed Electra. Tragically, Earhart and her aircraft did not return from this historic flight and after exhaustive searches, Earhart was declared dead in 1939. The trophy was later given to an Amelia Earhart American Legion Post in California.
In 1997 the National Aviation Club resurrected this trophy in honor of the Stinson sisters. In 1912, Katherine Stinson became the fourth woman in the United States to obtain a pilot's license. Her sister Marjorie Stinson followed, obtaining her license in 1914.
The Stinson family established their own flight school in San Antonio, Texas. Both Stinson sisters were instructors, their brother Edward acted as chief mechanic, and their mother, Emma Beaver Stinson, became the business manager. The Stinson sisters trained pilots for World War I.
The Stinson sisters were early female pioneers in aviation, and Earhart followed in their path. It’s only fitting that this trophy represents these historic achievements of women and is still celebrated today. The Stinson Trophy is now awarded annually by the National Aeronautic Association (NAA) for women’s achievement in aviation and space. Recent recipients include Wally Funk, Ellen Ochoa, and Shaesta Waiz.
In the Conservation Lab
Prior to any artifact treatment it is essential to conduct a thorough assessment and to determine what the object is composed of. In order to repair the Stinson trophy, it was important to determine the composition of the metal. At first glance, the trophy appears to be made of a copper alloy, possibly bronze (an alloy of copper and tin). However, upon closer inspection and researching the historical record, contradicting information emerged. One source said it was pewter, a very soft alloy of tin, and another source said it was made of zinc and electroplated with a layer of copper.
We used a portable x-ray fluorescence spectrometer (XRF)to help characterize the composition of the trophy. XRF works by bombarding the sample to be tested with X-rays. X-rays displace electrons in the atomic orbitals of the atoms in the sample, which releases a burst of energy. This release in energy is analyzed by the instrument providing an analysis of the elements present in the sample.
The presence of zinc and lead with little indication of any trace elements such as tin indicates that this trophy was composed of a zinc-lead alloy known as spelter. Spelter is an old name for zinc, and in the past, the term was sometimes used to describe brass which is a copper/zinc alloy. In the case of this trophy, the more contemporary meaning of spelter applies, indicating a zinc/lead alloy.
Spelter was commonly used to cast decorative sculptures as early as the late 19th century. It was a lighter and cheaper option compared to cast bronze. Spelter was often plated with copper and patinated to resemble bronze, as this trophy is. The downside of spelter is that it is brittle and prone to cracking. More importantly, it has a low melting point, making traditional soldered repairs challenging.
We decided to still use the traditional method of soft soldering for the repair, as that was how the trophy was originally fabricated and previously repaired. To avoid melting the spelter alloy of the trophy, or disturbing the previous soldered repairs, a new solder with a very low melting point was needed. A special low temperature tin/indium alloy solder which melts at 275 degrees Fahrenheit was chosen.
The first step in the treatment required disassembly. The threaded steel rod was unscrewed from the wooden base. The original cast brass support bar, which had broken away from the inside of the trophy base, was unscrewed from the other end of the steel rod. Next, the excess solder was removed from the support bar and the surface was cleaned using glass media blasting. A large amount of tension is focused in this area in order to secure the trophy to a large wooden base, so, it was decided that a supplementary support bar was required to prevent another break.
The support bar was fitted into the base of the trophy and carefully soldered into place using the low temperature tin/indium alloy. This was by far the most delicate part of the entire repair, because if the spot was overheated, it would melt the original metal, causing severe damage to the trophy. Due to careful planning and implementation of the repair, it went off without a hitch. Finally, the trophy was reinstalled back on its base in a much more secure condition.
Although a tragedy prevented this trophy from being presented to Amelia Earhart, it lives on—representing her vision and spirit as a female aviator and honoring the Stinson sisters. With the new repair and reinforcement, the trophy will be displayed safely to the public in the future, receiving a new lease on life. The trophy will stand proudly on display in the newly renovated Museum and will honor female aviators for future generations to come.