Important factors in the weathering of commercial flint glass containers were determined by the storage of empty bottles, capped & uncapped, of 10 different compositions for periods up to 13m at (1) 100 deg F 80% relative humidity; (2) 120 deg F 15% relative humidity & (3) normal room conditions. The effect of storage was determined by visual inspection, tests of the alkali extraction by water at elevated temps & photomicrographs of the weathered surfaces. Results obtained indicate that the most important factor in the weathering conditions used is humidity. Although the weathering produced depends on several factors, the important weathering effect of high humidity may be significantly controlled by the chemical composition of the glass. Storage for periods used at low relative humidity or at normal room conditions was relatively ineffective for weathering any of the bottles tested. Photomicrographs of representative weathered internal and external bottle surfaces are shown. A microscopic examination of these surfaces revealed the presence of calcite.
