22 Sep
2014
22 Sep
'14
2:02 p.m.
On 09/20/2014 05:24 PM, Tony Duell wrote:
The other sdie to thsi is that a CRT showing 'fungus' is possibly less
safe tha na good one.
Given that it appears the adhesive bwetwene the 2
layers of the CRT
faceplate is part of the protection (as in 'laminated glass). I wonder if
a CERT showing 'fungus' (for want of a better term) is actually unsafe.
The adhesive has decayed, will it hold the layers together if the CRT
implodes?
When I removed one using a heated wire, there were noticeable large areas -
much larger than the visible problem spots - where there was very little
resistance to the cutting; I suspect there was little bond left between the
faceplate and the CRT (and completely removing the adhesive perhaps made
little difference[1] to the safety of the device).
That perhaps raises the question whether there are CRTs out there with
weakened adhesive, but which don't show any visible signs of decay.
Quite possibly. I've never seen manugacturers warn about this, but...
[1] I've never personally had a CRT implode; it'd be interesting to know
Nor have I.
how common it is (and if there's perhaps a
difference between the CRT's
used in TVs and those used for computer displays?)
The CRts in TVs and in computer monitors are basically the same devices
(certainly in th TV rate montiors and terminals used with classic
computers), and I suspect have the same risk of implosion.
I ws told there were some nasty accidents in WW2. Basically, aircraft
radar operator is looking at the screen of a VCR97 (or whatever) down a
viewing hood. Plane has a crash landing, or is caught up in an explosion,
or whatever. CRT implodes. Radar operator gets a faceful of glass shards.
This may be why all post-war TVs had implosion protection. The danger,
however slight, was there, and was known to be there. I don;t know about
pre-war TVs. Did they have implosion guards? A number of UK sets had the
CRT mounted vertically (screen upwards) with a front-slivered mirror
above it ot reflect the picture to the viewer (This was becuase the
small deflection anlgle meant the electron gun was a long way from the
screen so the cabinet would have bene ridiculously deep if the CRT had
been fitted in the obvious way). In which case an implosion would be messy,
not really dangerous.
-tony