An exposure test of porcelain enamels on aluminum was initiated by the National Bureau of Standards and the Porcelain Enamel Institute in 1964.The enamels were returned from the exposure sites to the laboratory at NBS to be measured for changes in gloss and col * or after exposures of six months, one year, and three years.Changes were found to be greatest at Kure Beach and least at Montreal and Los Angeles, with moderate changes occurring at Washington and New York.Although the boiling citric acid test is used as an acceptance test for these enamels, the correlation with color change, particularly at Kure Beach, was not as good as expected.A cupric chloride test was developed which shows an improvement in this correlation.(Author).

The paper presents a resume of current practice in the U.S. with regard to the use of sandwich panels in single-story buildings. A description and the properties of typical paper honeycomb cores are given. Some of the factors which are considered in choosing sandwich facings and adhesives are given.

The weather resistance of 192 porcelain enameled panels representing 14 enamel types was evaluated after being exposed for 30 years at Washington, D.C.A direct correlation was found between the acid resistance and weather resistance of the enamels tested.The porcelain enamel protected the base metal from corrosion if the initial coverage was complete.Similar evaluations and findings were made on 58 panels representing 13 enamel types that were added to this test in 1947.(Author).