Vibration cracks a car rear window - GIF

[ToolTalkBot]

Vibration cracks a car rear window.




Previously:

Anti-vibration disc assembly machine - GIF
Anti-vibration impact wrench - GIF
Anti-vibration jack for beds - GIF
Demonstration of concrete vibration - GIF
Truck cab vibration testing system - GIF

[hemmjo]

Glass is fascinating material.

In my younger days one of my most educational jobs was working in an auto salvage yard. One day, I do not remember the reason, I had to get into a locked car. No big deal, just pick up the steel wheel laying right there. Throw it against the side backdoor glass. Get in. HA, I was shocked when that wheel did not break the glass.

After 4-5 tries, one of the veteran yard men came by, laughing. He had a little ball peen hammer, one smack, not even a hard smack, glass was gone.

I learned a lot working there.

[RetiredFAE]

Repo'd cars when I was younger, old timer taught me to take a spark plug, put it in a paper bag, hit it with a hammer and shatter the porcelain insulation.
Take a piece of it the size of your little fingernail, and flick it against the glass window, it would shatter and fall out quietly. The razor sharp edge of the porcelain chip did the trick.

[PJs]

Over my years I've used a pickle fork many a times but never like this. Didn't realize it would ring like a tuning fork....I'll have to try mine for ringing. Curious if it would work using the butt end of it or if it is just because the sharp end worked like the porcelain did. Not sure the frequency had something to do with it especially on tempered glass being laminated?

I keep a spring loaded center punch in the car just for safety to be able to get out in an accident...the cops/first responders use the same thing in rescues.

[hemmjo]

Windshields are laminated but not tempered. Don’t want all those tiny fragments hitting you in the face when a rock hit you at speed.

Side and back glass are tempered.

At least back when I was working at the yard.

[RetiredFAE]

Yup, side glass shatters, and creates sharp shards, windshields are safety glass, and yet as first responder, I have seen a lot of folks with a face full of those supposedly dull edged "balls" of glass it is supposed to produce.
Which is why I always wear safety glasses when riding in or driving a car or truck.