Cleaning Stained Glass - Owners Manual
Domestic stained glass windows are harder to clean than plain glass windows and easier to clean than the painted stained glass in church windows. If your window has a design painted on the glass (on purpose), these tips are not for you.
Some cleaning products should not be used on any stained glass window. The extreme pH of ammonia and vinegar can attack the metallic structure of the lead or zinc cames. Scouring pads and powder can scratch the glass. Chemical paint stripper dissolves the putty between the glass and the cames. Excessive moisture on a window will lift the gold in the mirrored pieces and eventually rot the wooden sash.
Supplies you can use:
- Non-ammonia based glass cleaners like Sparkle or Sprayway
- Crumpled-up newspaper, old rags or Scott's Shop Towels
- Old toothbrushes and new Qtips
- New single-edged razor blades and extra-fine (#0000) steel wool
Whiting - powdered calcium carbonate - is a safe, chemically inert fine white powder. Produced by Synko and AmChem, it is sold in hardware stores, paint stores and stained glass supply stores. Substitutes may not be chemically inert and should not be used.
Cleaning the glass:
- Clean each piece of glass separately. Spray the cleaner onto the cloth - not the window - and clean each piece as you go.
- Since all glass cleaners leave streaks, polish each cleaned piece of glass with a dry rag dabbed onto a small amount of dry whiting. Use as little whiting as possible.
- Qtips are excellent for cleaning small pieces of glass and getting into corners.
- To clean textured glass, use a couple of old toothbrushes - one for the cleaner and one for the whiting.
- Paint spatters can be carefully scraped off with a new single-edge razor blade. Coarse or synthetic steel wool or Scotchbrite pads will scratch the glass.
- Some varnish and paint can be dissolved with denatured alcohol or acetone. Use sparingly - these chemicals can damage the varnish on your woodwork and they can damage you.
- Do not remove the putty under the cames - without the putty the window will leak rain and cold air, rattle and eventually break.
- Do not try to polish the lead or zinc cames - they are supposed to be dull gray or black. If they are really dirty, run #oooo steel wool over them lightly.
- Do not ignore the condition of the wooden sash. The glazing putty should be intact and the outside of the window should be painted.
If your stained glass window is not flat, if it rattles in the wind and the cames remind you of powdered sugar or a salted pretzel, the window needs professional help. Most studios offer free, on-site estimates.