Glass Breakers

[Jim the Brave]

So many knives have glass breakers on them. Please talk to me about glass breakers.

I'm like--you know, most any hard object should be able to break glass. Like the butt end of most any large knife?  So...is it to break the glass in a more controlled way?

And some knives have replaceable glass breakers. So why don't we have replaceable other parts? How many times do you have to break glass before you wear out your glass breaker? Seriously? If it were called a concrete breaker I suppose I would understand....

What am I missing here?

Maybe I've just never intentionally broken glass before?

[enki_ck]

Breaking regular glass might be easy, but car windows are a different best all together.

It's an old video but always gets me

https://www.youtube.com/watch?v=L91_K-s4pMM

I prefer having something spring loaded, it's not guaranteed you'll have enough space inside a car to swing something or the strength to do so. So I have a Resqme attached to my gear shift with a wire tie.

[ddogu]

Breaking regular glass might be easy, but car windows are a different best all together.

It's an old video but always gets me

https://www.youtube.com/watch?v=L91_K-s4pMM

I prefer having something spring loaded, it's not guaranteed you'll have enough space inside a car to swing something or the strength to do so. So I have a Resqme attached to my gear shift with a wire tie.

 

[Aloha]

That video is a good one and a reminder its not always easy to break car windows.  Laminated ones would be even more difficult.  The idea of a glass breaker is to concentrate the impact.  Enki's rescueme does exactly that.  I keep a spring loaded center punch in my vehicle. 

Glass breakers on knives are supposed to work on the premise of concentrated impact.  Some are good and some not so much.  Also when breaking a car window with a knife you'd want to be sure not to get cut as your hand goes thru the window. 

[theonew]

This always kind of blows my mind:

http://www.youtube.com/watch?v=i8-mJuQLRbM

But yeah I carry a Resqme on my gear shift.

[Jim the Brave]

Ok, good deal. So do they really wear out?

[Aloha]

The pot metal ones I can see flattening but harder steels not likely. 

[pfrsantos]

So many knives have glass breakers on them. Please talk to me about glass breakers.

I'm like--you know, most any hard object should be able to break glass. Like the butt end of most any large knife?  So...is it to break the glass in a more controlled way?

And some knives have replaceable glass breakers. So why don't we have replaceable other parts? How many times do you have to break glass before you wear out your glass breaker? Seriously? If it were called a concrete breaker I suppose I would understand....

What am I missing here?

Maybe I've just never intentionally broken glass before?

If you're a fireman fireperson / policeman policeperson, you might end up using the glass breaker quite a lot.

 

[pfrsantos]

This always kind of blows my mind:

http://www.youtube.com/watch?v=i8-mJuQLRbM

But yeah I carry a Resqme on my gear shift.

I remembered this at once. Maybe it would be a good idea, combining a glass breaker with this ceramic material.

 

[Etherealicer]

I have posted this reminder many times:
The US has a law (in effect since 2017) requiring side windows to be laminated. Posh cars (Mercedes, Audi etc.) have been using laminated glass for side-windows for a while.

So, glass breakers on knives become more and more hot-spots, rather than something useful.

Good video by resqme
https://www.youtube.com/watch?v=8oZokI0UrHI&ab_channel=resqme

[Aloha]

 

[SirVicaLot]

I have posted this reminder many times:
The US has a law (in effect since 2017) requiring side windows to be laminated. Posh cars (Mercedes, Audi etc.) have been using laminated glass for side-windows for a while.

So, glass breakers on knives become more and more hot-spots, rather than something useful.

Good video by resqme
https://www.youtube.com/watch?v=8oZokI0UrHI&ab_channel=resqme

Thanks for the video. I just checked our cars, and both have tempered glass. So we are still good with our resqme’s 

But what about laminated glass? Are there any tools available for consumers for quick escape scenarios?

[Etherealicer]

Thanks for the video. I just checked our cars, and both have tempered glass. So we are still good with our resqme’s 

But what about laminated glass? Are there any tools available for consumers for quick escape scenarios?

Victorinox Rescue, the glass saw is exactly for that... although you probably want something bigger

[Etherealicer]

Just stumbled onto this:
Appears Mercedes has been using laminated glass for quite a while (front row, but not back row). This image is from the Mercedes Rescue Manual from 2012. I think it is really important that you check your windows, so you know what is up.
Full manual here

[Aloha]

I'd agree you should check your window to be certain.  I recently test drove a 2021 Rav4 that did not have laminated side windows.  I think ( very well may be wrong ) that only the upper trim levels or luxury vehicles will have side laminated glass. 

That said, you should know how to break a non laminated window as you could hit one a few times with no effect.  I feel confident my spring loaded center punch applied to the corner will do the trick. 

Not so sure how I'd approach how to extract myself from a vehicle with side laminated glass?

On laminated glass the interlayer provides three beneficial properties to laminated glass panes: first, the interlayer functions to distribute impact forces across a greater area of the glass panes, thus increasing the impact resistance of the glass; second, the interlayer functions to bind the resulting shards if the glass is ultimately broken; third the viscoelastic interlayer undergoes plastic deformation during impact and under static loads after impact, absorbing energy and reducing penetration by the impacting object as well as reducing the energy of the impact that is transmitted to impacting object.  The inner material typically of polyvinyl butyral (PVB), ethylene-vinyl acetate (EVA), or Thermoplastic Polyurethane (TPU).  info sourced from WIKI [/i] 

We've had some discussions on self extracting from a car and with laminated glass you're going to have to be prepared more so.  I think a saw or serrated blade could cut the inner material  .  I'd want something with length but your first order of business is breaking then puncturing thru the material within.   

Gloves would be a good idea.   

[Old Boy]

Ok, good deal. So do they really wear out?

My Resqme wore out in that the spring broke. But had nothing to do with any usage. Just metal fatigue of some sort and the plastic casing was getting some cracks. Probably due to sun exposure as I kept it as a spare inside the car clipped to the visor. 

So best to test it once in a while for replacement. Don’t want to find out in the worst possible way. 😂

[Aloha]

Good idea. 

[Etherealicer]

I'd agree you should check your window to be certain.  I recently test drove a 2021 Rav4 that did not have laminated side windows.  I think ( very well may be wrong ) that only the upper trim levels or luxury vehicles will have side laminated glass. 

Not a lawyer, but to my understanding that should not be. At least not in the US.
Federal Motor Vehicle Safety Standard 226 (FMVSS226) requires that all cars produced/sold (don't know which one) after September 1st 2017 must have laminated side-windows.

Unless that has changed again. Or I'm misinformed. Or maybe they have improved tempered glass, so it meets the requirement of FMVSS226.

[Aloha]

 

[Jim the Brave]

I just received a StatGear GovX rescue knife in a confiscation lot from Las Vegas. I had not been familiar with them either, but this one seems to be in great shape and has a spring-loaded glass breaker. (I tried it out on my wooden desk, works great!  )

The GovX knife seems to be a very legitimate rescue tool, with 4 hard-core useful features...the main knife blade (liner lock drop point with partial serration), the hook blade belt cutter on a separate fold out blade, also liner locking, the spring-loaded glass breaker, and a functioning led-light, which shines directly inline with the main blade or hook blade when they are deployed. After seeing a number of different low-grade "rescue knives" or knives with rescue functions pass through my hands in the last few months, I'm impressed with the package included on this knife. Since y'all have educated me on the science of glass breakers, I now appreciate the spring-loaded one in this knife. 

[ddogu]

Just ordered a second-hand LM Raptor in good shape. Let me break a few glasses and I'm gonna let you know how it performs when they let me outta jail

[Jim the Brave]

Just ordered a second-hand LM Raptor in good shape. Let me break a few glasses and I'm gonna let you know how it performs when they let me outta jail

Sounds good.

You might get that old red letter warning: "Warning! This thread has not been active for more than 90 days. Do you really want to reply to it?"

[Fireman]

We've had some discussions on self extracting from a car and with laminated glass you're going to have to be prepared more so.  I think a saw or serrated blade could cut the inner material  .  I'd want something with length but your first order of business is breaking then puncturing thru the material within.   

Gloves would be a good idea.

Although laminated side windows were in use while before I retired, we didn't encounter them often.  There were a lot of windshield removal techniques (unnecessary IMO but that's another topic).  There are specific rescue saws for glass, but an axe also works (small chops, not like a lumberjack). 

If you're injured, I don't think you're going to cut your way out with a small saw blade.  If you're not injured, check to see if you can put down windows or open doors.  Also, you might be able to lie on your back and use both feet kick out broken laminated glass more or less in one piece. 

[Jim the Brave]

Although laminated side windows were in use while before I retired, we didn't encounter them often.  There were a lot of windshield removal techniques (unnecessary IMO but that's another topic).  There are specific rescue saws for glass, but an axe also works (small chops, not like a lumberjack). 

If you're injured, I don't think you're going to cut your way out with a small saw blade.  If you're not injured, check to see if you can put down windows or open doors.  Also, you might be able to lie on your back and use both feet kick out broken laminated glass more or less in one piece.

I know one thing that shatters a whole safety glass window instantly..... Try to drill a hole in it with a drill. My dad did that..... "POP" the whole thing disintegrated.

[Aloha]

Thank you Fireman.  I sure wouldn't want to have extract myself. 

[Fireman]

I know one thing that shatters a whole safety glass window instantly..... Try to drill a hole in it with a drill. My dad did that..... "POP" the whole thing disintegrated.

Drilling a hole for...never mind.    That would do it though.  My favorite trick was using the car antenna, if the car had a metal antenna mounted near the windshield.

[Jim the Brave]

Drilling a hole for...never mind.    That would do it though.  My favorite trick was using the car antenna, if the car had a metal antenna mounted near the windshield.

Well to tell the truth, the reason he was trying to drill a hole through it, was to attach a bolt because he was having a hard time getting the glass to stay on the crank riser.

Come to think of it, though, I can think of a few other reasons somebody might want to drill a hole in one.....

[Fireman]

Well to tell the truth, the reason he was trying to drill a hole through it, was to attach a bolt because he was having a hard time getting the glass to stay on the crank riser.

Come to think of it, though, I can think of a few other reasons somebody might want to drill a hole in one.....

I'm don't mean to pick on your dad, but I can see it all happening.  Patience...patience...POP.  It's pretty incredible what they can withstand while fully up in the frame, but that they are relatively easy to break with pressure on a small point.

[Jim the Brave]

I'm don't mean to pick on your dad, but I can see it all happening.  Patience...patience...POP.  It's pretty incredible what they can withstand while fully up in the frame, but that they are relatively easy to break with pressure on a small point.

Yes, it's the nature of the whole thing.

[Scorpion Regent]

A glass breaker isn't really necessary unless your day job  is fire/rescue.  Any MT with a inline phillips screwdriver can be used to break glass.  A needle nosed plier MT might work as well.  it's all about focussing all your force on a single point.