CRT implosions

[Tony Duell]

> 
> J.C. Wren wrote:
> > Some useful information here: 
> > http://repairfaq.ece.drexel.edu/sam/crtfaq.htm#crtcir
> 
> Rats, I almost checked there before posting too, but didn't recall any 
> such section on the site!
> 
> Interestingly, that info implies that it's the steel strap around the 
> perimeter of the CRT's face which does the implosion protection, and 

That strip, normally called the rimband over here, is certainly for 
implosion protection in some CRTs. But I suspect the double faceplate is 
part of the implosion protection too. 

> bit at a time. Given the huge thickness of the CRT face* I would be 
> surprised if heated wire could cause it to break (the faceplate's 

Actually, one of the easiest ways to get stresses in glass is from uneven 
heating/cooling (but I suspect the wire you used didn't get the glass 
itself anything like hot enough for this to be a problem).

> another matter as it's so thin, which is really why I was being careful 
> about the heating). Just a case of being careful though I suppose.
> 
> *I recall breaking TV CRTs apart as a kid and the glass at the front is 
> amazingly thick. Bricks bounce off happily without damaging the screen 
> at all.

Work out the force on the faceplate due to air pressure (which you can 
assume is 14 pounds per square inch). It's pretty large for TV-sized CRTs!

-tony