What we can do

Grinding glass surfaces

  • We remove scratches and cement traces from window glass on site in a very professional and uncomplicated manner.
  • We grind the glass to micromillimetre precision.
  • The trained eye and precision of our technicians ensure that any possible distortions that arise are faded out so that they are no longer visible.
  • Thanks to our SRT grinding process (Schleif-Reparaturtechnik = Grinding Repair Technology), it is also possible to repair deeper scratches that can be felt with your fingernails.
  • We work strictly according to Swiss and Euro glass standards.
  • We prepare neutral expert opinions upon request.
  • We work together with WORKcontrol Suisse AG.

Get in touch with us before you replace your expensive glass! We will be happy to provide you with a non-binding and transparent offer after carrying out a detailed damage assessment on site. We look forward to scheduling an appointment with you.

Glass Wizards Chef-Techniker: Simone Licchello
Glass Wizards Techniker: Jonathan Licchelli

Simone Licchello
Chief Technician

Jonathan Licchelli

Glass Wizards Mitarbeiter beim Schleifen von Glas

What we can do ...

... and what we cannot.


  • Laminated safety glass, also with UV protection (VSG glass)
  • Toughened safety glass (ESG glass)
  • Partially toughened glass (TVG glass)
  • Multipane glazing
  • Fixed glazing
  • UV glass (if UV protection is not on the outside of the glass surface)
  • Fire-resistant glass
  • Sound-insulation glass
  • Glass shower enclosures
  • Glass partitions or glass doors (e.g., in offices)
  • Winter gardens, balcony and seating-area glazing
  • Mirrors

Not treatable

We cannot repair surface-treated glass (if coatings/foils are applied to the outside of the glass), such as:

  • Nano-treated glass (lotus effect)
  • Printed panes of glass (e.g., for advertising purposes)


  • No damages from sparks
  • No stone chipping
  • No scratches on ceramic hobs (devitrified glass)

In addition, when the temperature outside is below 5° Celsius, panes cannot be processed on the outside because this would lead to stresses in the glass.

Icon: Glass Wizards, Was wir nicht könnenIcon: Glass Wizards, Was wir nicht können
Icon: Glass Wizards, Was wir könnenIcon: Glass Wizards, Was wir können

Why we do not process glass panes with treated surfaces

If surface-treated glass is ground, the corresponding layer that gives the glass the additional benefit is automatically removed. That missing layer would, therefore, have to be reapplied afterwards. This is usually not possible on site because surface treatments are complex technical processes. These processes can only be carried out with the necessary standards under industrial conditions. A proper nano treatment, for example, cannot simply be carried out on site; it requires a completely dust-free processing cabin. Further, the necessary health precautions that the staff must follow during the process cannot be observed.

Damages from sparks ...

... cannot be removed because we do not make “molecules dance”. 

Processes such as grinding, cutting or welding metal produce sparks that are thrown through the air. If these land on a nearby glass surfaces, typical sparking marks can occur on them. These extremely hot but tiny metal particles cool down relatively slowly and melt into the glass surface they hit. 

To grind these metal dots from the glass, the glass would have to be ground down so deeply that distortions (a so-called lens effect) are unavoidable. 

Now, one could claim that the high heating, by means of strong grinding, makes the “molecules dance” and thus changes the viscosity of the glass. However, that would mean that the glass in the frame would liquefy. Now, that’s an absurd idea! 

As a company that takes its work very seriously, we, therefore, make no such promises and clearly show where the limits of the laws of Physics lie.

A spark is a glowing particle that is produced during combustion processes, friction processes or electrical discharges and moves through a gaseous medium. These tiny particles are then referred to as flying sparks.

Source: Wikipedia

Stone-chip damages ...

... we did fix earlier when we established our windscreen repair business (MWR AG for Mobile Windscreen Repair).

However, now, we have started to focus entirely on grinding scratched glass surfaces. We are specialists in this and this is our strength.

Scratches on ceramic hobs (devitrified glass) ...

... cannot really be removed or repaired. However, one can ensure that those scratches are not easily noticeable. If you want to remove a scratch completely, you would have to polish or grind the areas immediately surrounding the scratch to the depth of the scratch. Glass ceramic, however, is much too hard for such grinding. The trick to removing scratches from a ceramic hob is rather to “make them invisible”. If you polish a scratch on the ceramic hob often and intensively, you round off the sharp edges of the scratch. This changes the refraction of light considerably. Toothpaste can be helpful for polishing. The microparticles of the toothpaste smoothen the edges of the scratches and thus make them disappear visually. To do this, it is sufficient to rub a small amount of the toothpaste onto the scratched areas with a cloth and then wipe the area dry with the back of the cloth.

Light refraction not possible

Because the light is no longer refracted, the scratch seems to disappear. The scratch is still there; but due to the poor light refraction, it is no longer visible. Really deep scratches are little more proplematic. In the case of such scratches, polishing can reduce the effect of the light refraction only by a certain extent.

No real repair options because of devitrified glass properties

The deep scratch in the ceramic hob will still be visible, but it will no longer be as clear and noticeable as before. Further, there are no putties or filling compounds, such as liquid glass, that you could use. The following basic properties of glass ceramic go against such usage. Devitrified glass:

  • is extremely heat resistant 
  • does not expand with heat 
  • does not contract in cold weather
  • is mechanically extremely resistant as it is very hard

GW-SWISS GmbH    Rietbrunnen 2    8808 Pfäffikon SZ    +41 44 915 03 81    info@glass-wizards.ch

GW-SWISS GmbH    +41 44 915 03 81