Mirrors spontaneously cracking

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In summary, the individual has experienced multiple instances of their mirrors cracking and is trying to figure out the cause. Possible explanations include thunder and lightning storms, internal tensions in the mirrors, or vibrations from the building. It is also suggested that the mirrors may have pre-existing microcracks that are becoming visible due to pressure differentials.
  • #1
derje
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Hi there...I've been searching the net and hoping someone can provide some insight.

I live in Toronto Canada in a high rise condo. I have several mirrors in my unit: some are hanging from the wall (they are approx 20 lbs); one is leaning against the wall (6 ft high x 4 ft wide); one is a sliding door to a closet (full mirror); one is a piece of furniture (a night table covered with mirrors).

I';ve had this condo since 2005. The closet mirror being there since it was built, and all other mirrors since 2009.

Last month after a thunder and lightning storm I noticed 3 of my mirrors all had cracks in the them on the corners. All the affected mirrors are also beveled.

Two days ago after returning from a week away, I noticed a forth mirror cracking. There was a lightning storm while I was on the airplane that lite up the sky.

Today I found the closet mirror (completely flat) that slides side to side - cracked on the corner as well!

My condo unit is next to a single elevator. I live across the street from a hydro station (sometimes when a transformer blows the unit shakes).

The mirrors cracked all recently and I am trying to figure out why all of a sudden this is happening and how I can prevent further damage.

Could it be due to the lightning storms?
 
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  • #2
I have a 4 x 3 beveled 20lb mirror hanging on my wall. Two days after hanging it there was a couple major cracks in the lower right corner. My 14 year old and 12 year old swear they didn't do it. I really don't care if they did I just to know if this thing is safe. Despite their repeated denial I have to assume they accidentally did it.
 
  • #3
They might be innocent after all because you cannot know whether the mirror had internal tensions which broke accidentally. If you want to be sure that it is safe, then you put a self-gluing transparent film on its surface, such that single parts cannot fall apart.
 
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  • #4
derje said:
cracks in the them on the corners
You mean a triangular piece broke off the corner?
 
  • #5
It sounds as if they were either mounted on an uneven surface, or framed in a frame that warped, resulting in some internal stress.

A loud thunder clap from a nearby lightning strike could have induced enough vibration in either the mirrors themselves or the surface they were mounted on to crack them, especially if there was some acoustical resonance. (plausible, but I don't know how probable o0))

Cheers,
Tom
 
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  • #6
Tom.G said:
A loud thunder clap from a nearby lightning strike could have induced enough vibration in either the mirrors themselves or the surface they were mounted on to crack them, especially if there was some acoustical resonance. (plausible, but I don't know how probable o0))
I lived in an old house with the original wood windows and the original glass made with the Fourcault process (that is, they have waves that distort the image seen through the glass), and they do vibrate - to the point of making very loud noises - when there is a loud thunderclap. But never they have cracked because of it.
 
  • #7
derje said:
I live in Toronto Canada in a high rise condo.
How high up do yo live? What floor?
Are the mirrors secured at the corners?
How rigidly-secured are they?

I am eyeing the swaying of the building in strong winds. If the mirrors are strongly secured, perhaps the distortions in the walls are twisting the mirrors.

(Although I'd expect you'd see cracks in the drywall first.)

I think I'd go with thunder claps afterall.
 
  • #8
move. it's a sign. bad mojo.
 
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  • #9
One plausible theory: All the mirrors have microcracks in them already, but you can't see them...and the thunderstorms are creating pressure differentials that cause those microcracks to become visible cracks. Why are they suddenly happening? One, either they have been happening, but you weren't looking for them, and so you missed them, especially when they were smaller. Or the temperatures or temperature changes in your place finally "cooked" the mirrors so that they are now permanently more brittle than they were and subject to pressure changes which reveal the microcracks?
 

Related to Mirrors spontaneously cracking

1. Why do mirrors spontaneously crack?

Mirrors can spontaneously crack due to a variety of reasons, such as thermal stress, physical damage, or improper installation. Changes in temperature can cause the glass to expand and contract, leading to cracks. Additionally, any physical force or impact to the mirror can cause it to crack. In some cases, mirrors may also have manufacturing defects that make them more prone to cracking.

2. Can a mirror crack on its own without any external force?

Yes, mirrors can crack on their own without any external force. As mentioned before, thermal stress or manufacturing defects can cause the mirror to crack without any physical impact. However, it is important to rule out any other possible causes, such as improper installation or small, unnoticed physical damage.

3. How can I prevent my mirror from spontaneously cracking?

To prevent your mirror from spontaneously cracking, make sure it is installed properly and securely. Avoid hanging heavy objects on or near the mirror, and avoid placing it in areas with extreme temperature changes. Regularly inspect your mirror for any signs of damage or defects, and replace it if necessary.

4. Is a cracked mirror dangerous?

Yes, a cracked mirror can be dangerous. The cracks can weaken the structural integrity of the glass, making it more likely to shatter. Additionally, the sharp edges of the cracks can pose a risk of injury. It is important to replace a cracked mirror as soon as possible.

5. Can a cracked mirror be repaired?

In most cases, a cracked mirror cannot be repaired and will need to be replaced. If the crack is small and only on the surface of the glass, it may be possible to repair it with a glass repair kit. However, it is recommended to replace the mirror to ensure safety and prevent further damage.

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