Glass is something that we all look through every day. When installed properly it gives us a clear view into the outside world. Unfortunately, glass that is damaged distorts and blurs our view of the outside world. Glass, being an organic and somewhat soft material, is susceptible to damage from many sources and during all stages of its life.
Glass that is damaged before installation is usually easy to spot. Generally, it consist of glass that is not properly tied down or isolated during transportation, this type of damage generally will consist of many scratches closely grouped together. Glass that is damaged during construction will usually have an irregular scratching pattern. This pattern can be created by careless workers rubbing against the glass or scraping it with metal objects.
Glass that is damaged after construction shows the most varied damage characteristics. The first way glass can be damaged after construction is in the post construction cleanup. While cleaning construction debris from glass, cleaners who use dull, chipped, or improper blades can leave the entire surface of the window covered in scratches. This type of damage creates a pattern that follows the flowing movement of someone quickly trying to scrape debris from a window. Damage caused by post construction cleaners is most frequently seen in tempered glass. Many large cleaning companies have a disclaimer in their contract making them not liable for this damage. This sort of damage is most notably a problem in either commercial or high end residential construction.
Another common type of glass damage is welding slag runoff. Welding slag runoff is small bits of molten metal that fly in all direction while people are welding. When these red hot pieces of metal come into contact with glass they burn their way into it, this is usually the deepest sort of glass damage. When the welding slag comes into contact with the glass it burns its way into the glass leaving a residual of the burnt metal as it burrows deeper into the glass surface. While this is frequently the deepest of glass damage it is not however always the most noticeable, welding slag can constantly look like specks on the window. Although these specks look like simple construction debris they can not be scraped off of the window.
Another type of damage is acid burn damage. Acid is usually the most visible but frequently the shallowest type of damage. This happens because acid splashes or sprays over large portions of a window, causing the damaged area to acquire a milky white haze in the damaged areas.
One final type of damage that comes from a more malicious source is graffiti. While paint graffiti on windows can be an annoyance it is easily taken care of with water and a razor blade. More difficult types of graffiti to deal with are scratch and acid graffiti. Scratch graffiti can range in severity from very light, similar to acid damage, to extremely deep, closer to the depth of welding slag. This damage is usually infected with the help of a diamond or glass cutting device.
Acid graffiti is hydrofluoric acid and is often applied using a brush or plastic shoe polish bottle. The amount to which the acid damages the window is dependent on two things the the acids purity and how long it is allowed to sit on the glass eating into it without being cleaned off.
All of these types of damage can be repaired. While there are a number of companies out there that claim to be able to repair this damage there are certain things to be aware of when deciding who to allow to do the repairs. Improperly done repairs can lead to distortion, waviness in the glass, and a slight cloud in the area repaired. While there are reputable companies who are able to repair glass without theses side affects you should be certain to bring up these issues with anyone you consider allowing to working on your glass.