Nevertheless, if you still think that the original glass has more value than the new glass, you can have the mirror fixed through “re-silvering.” Re-silvering is a process wherein the silver coat at the back of your antique mirror will be scraped off and restored.
In order to re-silver a mirror, you will have to remove it from its frame. This is a good time to see if the frame itself needs to be strengthened or repaired. The best time to do this is after you have carefully removed the mirror. Re-silvering a mirror does not affect the glass itself.
Clean the mirror with glass cleanser, shaving cream, or vinegar. Once you've removed dirt and gunk from the mirror, you'll be able to see better where the mirror is clear or cloudy. Then wipe the surface of the mirror with glass cleanser, shaving cream, or vinegar until the cloudiness disappears.
Mirror resilvering is not a do-it-yourself project. DIY-ers will actually touch up their mirror resilvering spray, but the results are usually disappointing. To properly resilver a mirror, the original mirror backing must be removed entirely and a fresh chemical coating of silver added.
The cause of foggy mirrors
Cloudy mirrors result from a buildup of residue that is natural. It can also be a result of damage to the backing of the mirror, which may indicate that it's time to replace your mirror.
Price will vary with age, condition, rarity, special features, materials used, maker or manufacturer, and the current interest which informs the market value. As a rough guide, you can expect antique mirrors in good condition to fetch somewhere between $600 and $6000 USD.
WD-40 Multi-Use-Product is a great alternative for cleaning glass surfaces and mirrors. It removes sticky residues and smears leaving you with clear glass. Always remove the product thoroughly with a dry cloth.
Mirror Rot is caused by moisture penetrating between the layer of glass and the layer of metal. Once water vapour has wormed its way in, the metal that makes your mirror shiny begins to react and oxidize (rust), turning an ugly black.
Moisture breaks down the bond between the glass and the backing product causing the silver layer to chip off leaving the mirror with black spots or edges wherever the silver layer is damaged. This can also break down due to age, incorrect glass cleaners, or faulty manufacturing.
White vinegar, rubbing alcohol and pure water are best for cleaning antique mirrors if you prefer using homemade cleaning assistants. You should avoid using any store-bought or homemade abrasive and harsh cleaning agent as it can cause more harm than good to your old friend.
Resilvering the Mirror
Resilvering your mirror is the only way to remove black edges; you have to use chemicals to strip the mirror of its backing and then follow an extensive process in order to resilver it.
Silvering is the chemical process of coating a non-conductive substrate such as glass with a reflective substance, to produce a mirror. While the metal is often silver, the term is used for the application of any reflective metal.
You can test this by holding the edge of a white card against the glass. If the card and the reflection are the same white color, the mirror was made after 1850. If the reflection is more yellow or gray, the glass was made before 1850. Mirrors in any traditional style can be found, some original, some reproductions.
You can restore your favorite mirror to its original luster with a re-silvering process. Even though a glass professional can remove the backing, strip the remaining silver, and apply new silver, this process is complicated and can get expensive.
Tear off small bits of aluminium foil and use the clear adhesive tape to tape those pieces over the black spots, being sure the shiny side of the foil is against the back of the mirror, and that the foil is as smooth as possible. Once all spots are covered, replace the frame of backing and rehang.
This is especially true when they are installed in moisture-rich areas, such as the bathroom. As time goes by, ugly dark spots and black edges can appear. What causes this dreadful damage? Mirror desilvering.
Silver Coated Glass Mirrors
In 1835, Justus Von Leibig started using silver instead of mercury to coat the glass, thus creating the silvering process that we still use today.
In a spray bottle, combine either ¼ cup vinegar with 2 cups water OR ½ teaspoon of Dawn Dish Soap with 2 cups water. Shake the mixture thoroughly. (If you've got hard water, consider using distilled water to clean your mirror so that it won't leave residue.)
You probably know using an all-purpose cleaner isn't the best idea, since it'll make the glass cloudy. But even mirror-specific products like Windex, while effective at cleaning, can leave your mirror full of streaks because they contain so much soap.
Even multi-purpose cleaners are too strong for cleaning mirrors. They often leave a toxic residue that makes mirrors hazy. Soapy cleaners also leave behind a residue that contributes to streaks, so avoid those too.
Distressed mirrors are sometimes referred to as antiqued or even vintage mirrors.
Types of Antique Mirror Styles
Georgian – features a restrained, symmetrical style with almost no carving. Neo-classical – popular in the 18th century, these mirrors feature rectangular shapes and medallion carvings, often with frames gilded with silver and gold.
Antique glass is typically thicker and heavier than modern glass to accommodate for the process of hand-blown glass production. It is essential to take note of how thick your antique mirror is. If it's a high-quality piece, it will have a thickness that you can easily feel when holding the item.