Cleaning and Maintenance of Leaded Glass Windows

The good news is stained glass windows do not show dirt and grime as readily as a clear glass window does. However, there is a course of action that you can take to keep your new windows looking immaculate or to bring back the luster to an older installation.

The primary cleaning for a stained glass window is to simply dust the inside surface occasionally with a soft brush. When a more meticulous cleaning is required, it is important to be conscientious of any painted areas on the window. Painted stained glass and particularly areas with enamel paint (opaque colors) are especially sensitive to acids, which means a vinegar and water solution could easily damage these areas. Be sure to test all painted areas with your cleaning solution prior to any thorough cleaning and avoid any areas in doubt. If your testing finds the painted areas to be stable, they may be safely cleaned along with the non-painted areas of the window.

Stained glass windows should be washed using a soft cotton cloth and a pH neutral cleaning solution mixed with distilled water. An excellent product is Triton X-100, a professional quality, non-ionic detergent (made by City Chemical Company of NY). However, most horse shampoos (available from any equine tack shop) are a safe and very effective alternative for cleaning stained glass windows. Since horse skin is more sensitive than human skin, horse shampoos are formulated to be pH neutral. Some cleaning compounds to be avoided are any that contain acids (such as vinegar), ammonia, and/or abrasives and never use scouring powders or steel wool scrubbers.

If your test cleaning indicates that the painted areas are unstable, especially if you found loose or flaking areas, it is better to leave the dirt on the stained glass rather than chance further damage to the window. Unstable paint could be the consequence of age, or may indicate the original artist used an improper paint formula or incorrect kiln firing procedure. Some historic stained glass windows were actually "cold painted" using standard air-dry paints that can easily be scraped or washed off the glass. When the window reaches the point of requiring a complete restoration, a qualified stained glass restoration company will address the problem of the unstable glass paint.

In addition to an occasional cleaning, the steel reinforcing system needs to be checked periodically to ensure it remains attached to the window's lead matrix. As leaded glass windows age, normal expansion and contraction may break the copper tie wires away from the round steel reinforcing bars. Or, if the more modern flat steel reinforcing bars are used, the solder joints connecting them to the lead matrix of your stained glass windows can break loose. The reinforcing bars need to be reattached to the lead matrix by repairing the wires or solder joints. This is a job for a professional stained glass restoration company. Windows assembled with dividing steel T-bars need to be inspected periodically for rust on the steel. If found the corrosion must be removed and the surface repainted.

Finally, windows set into their frames with glaziers putty should have any loose or missing putty replaced on a regular basis. To maintain a strong physical integrity, a stained glass window depends on a solid setting and tight installation.

Time and money spent on preventative maintenance will save money in the end as it prolongs the life of your stained glass and delays the time until costly restoration will be required. Few products made today are expected to last for centuries. Stained glass windows have a long life expectancy and a good maintenance program will preserve your stained glass heritage for centuries.