CRT implosions

Bill Pechter pechter at
Tue Oct 4 19:39:39 CDT 2005

That's how I scrapped out VT100 tubes at DEC and elsewhere. 

That's kind of a controlled failure since the suction pretty much is 
controlled by the small input at the back of the neck.

An uncontrolled failure could be different.  I've seen one old 1960 
vintage tv blow up and the glass was retained by a plastic or glass 
sheet across the black and white tube.

Never saw anything like a real accident, though.


Curt @ Atari Museum wrote:

> I'll never seen anything horrendous in so far as implosions.   I used 
> to service Mac's "back in the day" and had to replace a few CRT's on 
> the original Macs.   Apple would send the replacement monitor in a box 
> and inside was another box that you placed the whole mac inside of, 
> you'd follow the standard discharge and then purposely snap the tip of 
> the neck off the back of the monitor before closing up the box and 
> disposing of it, it was a scary moment the first time, but just a 
> quick zip of air and it was done, never had anything happen, did a few 
> dozen monitor replacements and disposals.
> Curt
> Jules Richardson wrote:
>> Tony Duell wrote:
>>> At least one person here has used a thin wire to cut the bonding, 
>>> then removed the front piece of glass, cleaned it up, and rebonded 
>>> it. It sounds like a dangerous project to me, not only because the 
>>> CRT could implode while you're cutting it, but also if you don't get 
>>> the bonding strong enough when you put it back together and the CRT 
>>> then subsequnectly implodes, the results would be very unpleasant.
>> That does beg the question of under what conditions a CRT implodes. 
>> Do age-related implosions happen (or implosions for other reasons 
>> other than mechanical shock)? I've never heard of a CRT imploding, 
>> except for when physical damage has occured to it - but presumably it 
>> does happen.
>> In other words what are the risks - or is it a case of 
>> over-engineering in the first place to make sure (to a reasonable 
>> extent) that there are no problems out in user-land?
>> Also curious as to the extent of the outward blast / debris field 
>> (that sounds horribly technical but I can't think of a better 
>> phrase!) when a CRT does implode. I'd *assume* glass just extends 
>> outward a foot or two, but happy to be corrected there! (of course an 
>> explosion would be a rather different matter)
>> Actually, is the faceplate actually there for dsamage limitation 
>> reasons - or in fact there to help prevent implosion in the first 
>> place from mechanical shock? I imagine that coupled with the sealant 
>> layer it provides a reasonable damper if the CRT is dropped with 
>> face-down.
>> Any people on the list involved (past or present)with CRT manufacture 
>> who can provide more information?
>> cheers
>> Jules

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