Article

Maintaining Your Stained-Glass Windows

The following has been extracted from the Standards and Guidelines for the Preservation of Stained (and Leaded) Glass Windows, published by the Stained Glass Association of America, 2012.

Routine Maintenance

Your stained-glass windows need routine inspection and maintenance to prevent premature deterioration. When routine maintenance is overlooked, deterioration can occur that will cause loss of historic and/or aesthetic value.

Routine maintenance starts with an inspection of the stained-glass windows on a regular basis. Paint, putty and caulk should be inspected once a year. For the stained glass, every five years is sufficient -- unless there are visible signs of accelerated deterioration, from which time the windows should be inspected once a year. Stained-glass windows that show no significant signs of deterioration -- no bowing and buckling, no daylight between the lead and glass, no broken wire ties, no failed support systems, no frame damage/weakness, no ventilator frame deficiencies -- can be routinely inspected by an owner or caretaker.

However, routine maintenance is best performed by a professional stained-glass studio. Routine maintenance includes: putty and caulk maintenance, window-frame maintenance and ventilator-frame maintenance. Routine maintenance, such as replacing missing putty or caulking and repainting frames, will help prevent premature deterioration of the stained-glass window.

Cleaning of Windows

Never run your finger along a painted window’s surface to test for dirt and dust. Oil residue may stick to the glass and unstable paint might be dislodged. Stained-glass windows can be carefully cleaned of dust with a soft duster, being careful not to snag any fibres in the leads. Any further action should be relegated to a professional stained-glass studio.

There are times when a stained-glass window needs to be cleaned, but does not require restoration. Dirt, grime, soot from coal or candle burning, and pollution residues may build up on both sides of the glass, reducing the amount of transmitted light. As a result, a window that was once brightly illuminated now appears to be muted and lifeless. Cleaning the glass will remove these deposits and allow the light to shine through the glass once again. Deep cleaning of stained-glass windows is not recommended because improper cleaning methods and harsh cleaning agents can damage the surface of the stained glass (especially painted surfaces). Cleaning of a stained-glass window is best done by a professional stained-glass studio when the window is restored.

A professional should confirm the stability of any glass paints before any cleaning is done, and even then, cleaning should proceed with caution. If the paint is stable, the window can be cleaned with distilled water and a soft cloth. If the paint was not fired properly or was not fired at all, the paint will remove easily when touched. If this happens, the cleaning process should be stopped immediately. It is better to leave the window alone at this point, and when it deteriorates to the point of requiring restoration, the condition of the paint can be addressed and the window can be carefully cleaned by a professional stained-glass studio.

Do Not Use:

• Ammonia-based cleaners
• Acid-based cleaners, including vinegar
• Solvents
• Steam or high-pressure equipment
• Any type of mechanical or air abrasive equipment
• Any caustic or abrasive cleaners such as oven or bathroom cleaners, scouring powders, steel wool, etc.

The damage that can be done to the stained glass by these products and methods is non-reversible.

For full information see: Standards and Guidelines for the Preservation of Stained (and Leaded) Glass Windows, published by the Stained Glass Association of America, 2012.