How to properly clean leadlight windows and leadlight glass

Many people find that leadlight windows are far harder to clean than plain glass ones, but we wanted to stress that it is possible to clean it yourself with very few problems. Some cleaning products should never be used on leadlight glass – the extreme pH of ammonia and vinegar, for example, can attack the metallic structure of the lead or zinc beading. Excessive moisture can lift the gold in mirrored pieces and will eventually rot the timber sash.

Fortunately, there are a number of cleaning products that are perfectly safe for use with leadlights. We recommend non-ammonia based glass cleaners, crumpled up newspaper or old rags, Q-tips, old toothbrushes, single-edged razor blades and extra fine (#0000) steel wool. If you come across a powdered calcium carbonate product known as whiting – which is chemically inert and fine – this is also safe for use on the glass as a polishing agent.

Cleaning Leadlight Glass
We have compiled a number of tips that you should keep in mind when cleaning the window. They will ensure that you don’t inadvertently cause more damage to the surface.

• Clean each piece of glass separately. Spray some cleaner onto a cloth – not directly onto the window.
• As all glass cleaners leave streaks, ensure that you polish each piece with a dry rag that has a small amount of whiting dabbed onto it.
• You will find that Q-tips are perfect for cleaning small pieces of glass and for getting right into the corners.
• To clean textured glass, use a couple of old toothbrushes (one for the cleaner and the other for the whiting).
• Carefully scrape off paint spatters using a brand new razor blade. Never use coarse or synthetic steel wool, as it will scratch the surface.
• Some varnishes and paints can be dissolved with denatured alcohol or acetone. Use sparingly, however.

What Not To Do
When cleaning leadlight windows, there are a number of things that you should not do if you want them to remain intact. We have outlined those cleaning activities that you should avoid.

• Do not remove the putty from underneath the lead or zinc beading – without the putty, the window will leak, rattle and eventually break.
• Do not try to polish the beading – they are supposed to be dull grey or black. If they are really dirty, lightly use the #0000 steel wool on them.
• Do not ignore the condition of the timber sash – the glazing putty should be intact and the outside should be painted for maximum protection.

If your leadlight window doesn’t seem to be flat, if you notice it rattling in the wind or if the beading reminds you of powdered sugar, you should seek professional assistance immediately. Either the timber sash or the leadlight glass itself has experienced serious damage, which needs to be rectified as soon as possible if you are to save the window. The professional will come out to your home and assess the damage, then offer suggestions on how to proceed.

The article was originally published here.