Simple tips to keep glass and ceramics beautiful
Glass and ceramic objects can be maintained for years of use and enjoyment provided that some basic care and attention is given to their preservation. The following information will help you care for objects and collections. The first step in the care of collections is to understand and minimize or eliminate conditions that can cause damage. The second step is to follow basic guidelines for care, handling and cleaning.
Causes of damage
Glass and ceramics are among the most durable antique collectibles. Breakage is by far the most common form of damage that occurs to both. Improper use, display, cleaning, or repair can cause additional damage in the form of stains and discoloration. In rare instances, poor manufacture or harsh environmental conditions lead to degradation.
Ceramics can become permanently stained by a variety of factors including inappropriate cleaning, repairs or careless use. Porous, unglazed or cracked ceramics can develop stains as a result of being soaked in water during cleaning. The absorption of colored materials such as foodstuffs, soil from potted plants, or rust from contact with metal objects can also cause staining. Antique ceramic dishes and bowls should never be heated beyond room temperature as elevated temperatures can cause the darkening of already existing stains.
In rare instances, a damaging condition called “weeping glass” occurs. Weeping glass manifests itself in the form of droplets of moisture that form on the surface of a glass object. These droplets of moisture can actually leach out unstable components of the glass producing an alkaline solution. If these alkaline droplets remain on the surface of the glass for a long period of time the surface will develop a fine network of cracks.
The primary cause of damage to both glass and ceramic objects is mishandling. Careless handling can result in breakage, chips, and scratches that mar the beauty of glass and ceramic antiques. The careful handling and storage of glass and ceramic objects is the surest way to provide protection. Always use two hands when lifting or moving objects, being careful to lift them from their strongest points.
The use of spring-type metal plate hangers should be avoided. These hangers place a great deal of stress on objects and can lead to the development of cracks. Metal hangers can also scratch the surface of the object. Plate stands constructed of hard plastic or painted wood that allow the object to rest at a tilted angle are preferable.
Archaeological and low-fired porous ceramics should only be cleaned by a trained conservator. The majority of ceramic items, however, can be successfully cleaned provided that a few basic instructions are followed. Some antique ceramics contain fragile painted or gilded surface decoration, which can be removed or damaged by harsh cleaning solutions. It is important to use only diluted cleaning solutions, applied with soft cloths during cleaning.
Glass can be cleaned in much the same manner as ceramics, with the addition of dilute ammonia as a cleaner. Weeping glass and archaeological glass should only be cleaned by a professional conservator.