Can a diamond be scratched from the mirror

How To: How to Fix a Mirror

Mirrors are our companions. In the morning they greet our tired faces in the bathroom and in the evening they bid us farewell to the land of dreams with a detailed reflection of our freshly brushed teeth. But precisely because they have been with us for such a long time and faithfully, they are prone to damage. However, stains, scratches, blind spots and the like do not always amount to a death sentence. Here you will find practical instructions for repairing damaged mirrors as well as important rules for handling reflective glasses.

Nobody would like to see such pictures at home.

How is a mirror made?

To manufacture a mirror, a glass plate is covered with a thin layer of silver - and in the case of cheap products, aluminum is rarely used. Since silver turns dark when it comes into contact with air, a layer of lacquer is then applied to protect it. This type of production has been used for over 100 years (source). Further information on mirrors can be found at: "Mirror facts that you are guaranteed not to know yet".


Dirt particles, grains of sand, stones, metals, diamonds: If the wrong materials come into contact with mirrors in the wrong way, e.g. with a lot of pressure, scratches can occur on the glass surface. The miracle cure against scratches on the mirror: Do not leave scratches! As know-it-all as that may sound, preventive measures are by far the most effective and cheapest way. Nevertheless, it can of course be damaged by a mishap or other circumstances.

Even the smallest scratches are laborious to repairwhich is why the removal is rarely worthwhile in private. With our current technical possibilities, it is usually cheaper to cut a new mirror. In the case of larger mirror elements such as shop windows, showcases, glass walls or high-quality glass tables, repairs by a specialist or a knowledgeable private person are definitely profitable. It is also worth repairing mirrors that have previously gone through several processing steps. This includes above all CNC milling, complex sandblasting, laser processing or mirrors with already integrated elements such as LED lighting. Even if there is no time for a new product, a repair can pay off. Some glaziers offer an on-site service for this.

This is how the repair works:

  • On the mirror surface and the grinding machine water applied
  • Cerium oxide (also called glass polish) is sprinkled over it.
  • The scratches are first ground out of the mirror surface with coarse cerium oxide and then with finer cerium oxide particles.

The following video shows how a professional can polish off scratches:

This procedure also helps with severe contamination on the glass. However, the method should as often as necessary and as rarely as possible be used because grinding can lead to indentations in the glass and thus to distortion of the mirror reflection.

Break or crack

Such a broken mirror is not only annoying, but also dangerous.

Deep scratches, cracks, cracks and breaks in the mirror cannot be repaired. The reason: there is currently no technology that can repair a break in the glass in such a way that it does not become distorted. Any attempt at repair remains visible and breaks the reflection.

In the case of mirror cracks etc., an attempt can only be made to prevent further damage and possible injuries to the user. Especially with so-called mussels (see following picture) it is dangerous to leave the break untreated, as the glass particles are extremely sharp.

The shattered shells in particular pose a high risk of injury.

Protect the mirror from breaks and others from injuries:

There are some to protect the cracked glass from further cracks preventive and retrospective measures. For this you should always work with appropriate cut protection gloves.

This film is usually applied prophylactically to the back of large mirrors, e.g. mirror walls in a dance school, in order to prevent injuries. Ceiling mirrors must also have such a device, otherwise their use would be far too dangerous. The principle of the splinter protection film: A tear-resistant film is attached between the mirror and an additional glass plate and prevents the mirror glass from crumbling or shattering. Instead of a second glass plate, a wooden plate for ceiling mounting is also conceivable, as long as the adhesive is applied flat. Here the effect is similar to that of a composite panel.

In private, a normal film with adhesive can also be used for this, provided the adhesive is solvent-free, as it would otherwise dissolve the varnish on the back of the mirror.

Bathroom silicone can protect the mirror from further cracks and us from injury. To do this, apply the silicone to the broken area and let it dry. However, since bathroom silicones are mostly acetic cross-linking (with the exception of neutrally cross-linking silicones, e.g. based on alkoxy), black areas are to be expected here. As a retrospective and temporary protective measure, this is hardly a problem.

A pane of glass can be attached to fixed mirrors in the event of breaks. This is stuck to the defective area with glue or mirror tape and stabilizes the construction until the mirror can be replaced.

Attention: All retrospective measures should only be used as temporary protection. In the long term, cracked mirrors must be removed or replaced - if possible by a specialist - as there is still a risk of injury after gluing.


In everyday life, the mirror comes into unintentional contact with substances of all kinds: whether toothpaste, cream, hair products, lime, grease stains from touch, paint residues from renovations or even felt-tip pen scribbles by the little ones. For everything that cannot be cleaned with water, there is usually a very simple solution.

Stubborn stains, e.g. paint stains

If the mirror is not removed while painting, such pictures are unfortunately not uncommon.

Paint stains and other stubborn debris can with dilute solvents such asAlcohol (spirit) or acetone removed. Impurities from waterproof felt-tip pens can also be removed in this way. Anyone who has children understands how important this information is (see picture below).

As with any damage or contamination of mirrors: Under no circumstances use vinegar, as it attacks the silver and lacquer coating on the mirror! In addition, all solvents must be removed from the mirror surface and edges immediately after cleaning, otherwise edge corrosion can occur.

This is how the repair works:

  • The alcohol or acetone dilution Apply to the appropriate area.
  • With a Rag Run over it in circular movements until the stain is no longer visible.
  • Dry wipe.

When the playful instinct of the little ones drains the nerves of the adults ...

Lime and water residue

Water or limescale residues are probably the most common mirror contamination.

For all other stains that cannot be removed by dry wiping, the following applies: if possible dry with triple or quadruple steel wool Clean (N # 000 or N # 0000).

This is how the repair works:

  • The mirror Wipe dry with a clothto ensure that there are no particles of dirt on the surface that could scratch the surface when you clean it.
  • The fine steel wool Move in circles on the dry mirror surface with light pressure until the stains have disappeared.
  • With a dry cloth any Remove the steel threads from the mirroras these can begin to rust.

Here one How-to video on water stain removal:

Blind mirrors

You'd think it was a work of art!

Blind spots can look "foggy", black, brown, dark gray or metallic, but they always have one common cause: The mirror's silver layer is oxidized. So the silver has changed into a new chemical state. This is a completely natural phenomenon of age in a mirror: over the years, the lacquer layer gets small hairline cracks that reveal the silver. In combination with the sulfur from the air, silver turns into silver sulfide, a water-insoluble salt (source).

Since the silver is between the mirror glass and the paint coating, blind mirrors usually cannot be repairedbut must be exchanged or accepted as individual works of art. In cases of mirrors with a high historical value and unusual decorations, the silver and lacquer coating are renewed every now and then in order to let the story of the individual piece live on. But that is reserved for the restorers!


This grate also looks artistic, but stands in the way of a clear view.

In rare cases, the manufacturing process, industrial processing or cleaning of mirrors can be different Metal abrasion on the mirror surface are located. In connection with moisture, this can rust and, in the meantime, bond firmly to the surface. In contrast to blind spots, this contamination is a superficial appearance that can be clearly felt. Correspondingly, rust can also be removed. The procedure described above with steel wool is used for this purpose.


In general, mirrors are only suitable for indoor use. However, it can happen that mirrors in the interior come into contact with outside conditions, for example when moving or through broken windows, etc. So-called weather stone, a phenomenon known from the restoration of old church windows, lies on this glass. However, this can be done with a dry rag and cerium oxide in circular motions removed.

The mirror multiplication table

Even with such small touches, the life of the mirror can be extended.

How to Protect Your Mirrors

  • Protect from heat (from around 70 degrees): extreme temperatures damage the silver layer.
  • Protect from moisture: Mirrors prefer it to be dry.
  • Ventilation: especially in the bathroom, where heat and moisture accumulate.
  • Never work with acids: They attack metals and thus the silver layer.
  • To clean coarse dirt, should only water and an alcohol or acetone dilutionwith a soft cloth or microfiber cloth be used. Then rub the edges dry well, otherwise edge corrosion can occur.
  • Always protect edges well during transport and assembly: For example with edge protection elements, as can be seen in the picture above.
  • If possibledry cleanto avoid water residue entirely.
  • When cleaning the bathroom Protect the mirror from water and chemicals and then ventilate it well.
  • During renovation work you should hang the mirrors in the bathroom.
  • Beware of glass cleaners: As the name suggests, these are suitable for glass, but not for mirrors. The nourishing oils contained in it can damage the silver and lacquer layer.
  • Beware of tile cleanersas these contain acids. They should never be used for mirror cleaning and, if possible, not in the vicinity of the mirror, as the acid reaches the silver layer via the air.
  • Beware of toilet cleaners: Aroma cleaners, toilet cleaners and toilet stones often contain sulfuric acid (H2SO4). The sulfur vapor reaches the silver layer via the air, where the silver is oxidized and converted into silver sulfide. The result? The mirror turns black. Especially in rarely used, small bathrooms, such as guest toilets, air, moisture and sulfur vapor accumulate and oxidation leads to irreparable damage to the mirror and other metals. Rust in the bathroom is often a sign of this sulfur effect. In extreme cases, the sulfur attacks the mirror lacquer, which means that the plasticizer contained in the lacquer emerges from the lacquer surface and covers it like a lubricating film. So Stay away from too much chemistry!

The basic rule of mirror protection: dry, airy, and no chemicals!

For more details on cleaning and protecting mirrors, see our article “How to clean mirrors correctly” (internal link).

Antique mirror: "Broken" mirrors as decoration

Blind spots as a stylish antique charm.

Nowadays, “broken” mirrors are sold more and more often as art elements in the furnishing industry. Some of the mirrors come out of production blind, because the stains are supposed to give rooms an old-fashioned charm. We have summarized other artistic uses of mirrors for you in our article “Mirrors in Architecture and Art”.

Image rights: 1)
Edding stains: somethingway; Rust on the mirror: akata
2) Oxidized silver layer against a red background and stain on the mirror: Marie-Christin Böttger.
3) Other pictures and videos: Andreas Studzinski