National Memorial Cemetery of the Pacific at Punchbowl
The National Memorial Cemetery of the Pacific at Punchbowl, set in the Puowaina Crater, was completed by the American Battle Monuments Commission in 1964. The Trani limestone was painted white during the 1980s to cover brown stains first observed during construction. About thirty years later, the owner wanted to restore the limestone by removing the paint, but questioned the cause of white stains that appeared following paint removal mockups. Around the same time, the owner also noticed orange stains on unpainted travertine at the map gallery. SGH investigated the cause of the stains and consulted on the stone for recladding the monument.
SGH tested paint removal products for the Trani limestone and evaluated performance based on mockups. We identified two products that effectively removed the paint and recommended monitoring for latent effects.
We collected samples of the Trani limestone and travertine to investigate the cause of staining. SGH performed laboratory testing, including petrographic and mineralogy examinations, x-ray diffraction characterization, and Fourier transform infrared and energy-dispersive x-ray spectroscopy.
The owner elected to remove and replace the limestone. SGH evaluated stone from two quarries and performed the following testing in our laboratory:
- Petrographic analyses to identify constituents and microstructures of the stone samples
- Accelerated weathering testing involving cyclic exposure to high levels of moisture and ultraviolet radiation
- Testing based on ASTM C97 to evaluate absorption and bulk specific gravity of the stone
The project team used our findings to help them select a new limestone cladding for the monument.