I like antique mirrors. Some people don’t because they just want to see their own reflection, but I think that antique mirrors really add to the look and feel of a room. If you have an antique bedroom set, why would you have a regular old mirror on the wall that anybody buy just about at any store?
However, antique mirrors do require extra care. You can’t just spray it with some glass cleaner and a newspaper like you can with the mirror in your bathroom, but they are not much harder to keep clean than keeping streaks off regular glass.
I’ve talked it over with some professionals and have come away with three different methods. All three involve using lint-free cloths. There are some microfiber cloths that work well, and some people use camera lens cloth. You can get packs of them online.
However, I was given a warning by every single person I spoke with. You have to be extremely careful to prevent “foxing,” which happens when moisture gets behind the glass and fogs up the silver. Slight foxing can give a piece a great look, but too much and you make it useless.
You can use a little paraffin (or kerosene) on your cloth. It helps protect the glass. You put it on, wipe off the excess, and let it dry. Please use paraffin in an area where you can open windows or keep it well-ventilated.
Ammonia is another good choice. Add a few drops to a bucket of water. Dip your cloth in it, wring it out very well, and then wipe from top to bottom in an S shape so that you don’t go over the same place more than once.
Lastly, you can use denatured alcohol (sometimes packaged as methylated spirits). It may have a bad smell because additives have been mixed with the alcohol in order to discourage people from drinking it. And while that does make it toxic, it is actually healthier for you than many artificially created cleaners. Denatured alcohol evaporates quickly, which will prevent streaks.
When a mirror gets too foxed, it will lose its reflective properties. If you like the frame and don’t mind, don’t worry. There is a process called resilvering, where a professional can try to restore or replace the layer of silver (or aluminum) behind the glass. Oddly, restoring a mirror can actually devalue the piece, so consider what your ultimate plan is. There is another option if the mirror is in really bad shape. An expert may be able to scrape the silver off the back of the original mirror and cut a new mirror to the same size. They make a vacuum seal with a water mixture to make the new glass stick to the old. This way, the original mirror remains but the reflection will be brand new.
As for the frames, it is best to simply wipe them down with a soft cloth and beeswax.
Follow these tips and hopefully you will be able to enjoy your mirror for a long time to come.