Protecting Stone
The longevity and usefulness of stone can be extended by sealing its surface effectively, so as to exclude harmful liquids and gases. The ancient Romans often used olive oil to seal their stone. Such treatment provides some protection by excluding water and other weathering agents, but it stains the stone permanently.
During the renaissance Europeans experimented with the use of topical varnishes and sealants made from ingredients such as egg white, natural resins and silica, which were clear, could be applied wet and harden to form a protective skin. Most such measures did not last long, and some proved harmful in the long run.
Read more about this topic: Stone Sealer
Famous quotes containing the words protecting and/or stone:
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—Ernest Renan (1823–1892)
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—Thomas Wolfe (1900–1938)