A (very short) cataract story

[Dave S]

Hmm, now I'm wondering if reinstalling the safety glass without it being bonded to the face of the CRT makes it less effective?

On the other hand, even with my fairly casual handling I have never managed to implode a picture tube and I don't know anyone who has.

Still, ya gotta wonder how it would behave in a worst-case scenario.

[DaveWM]

it behaves badly, large chunks of CRT over a 20f radius, at least on the rectangle. I have not witnessed a roundie implode. on and the rectangle let go after a somewhat "difficult" attempt at the removal of the bonded lens.

https://www.youtube.com/watch?v=lRJ0otqgmYs

I am sure the bonding agent is a good idea, but not cheap, a while back I looked in to optically clear PVB (think that is what it was) that cures from exposure to UV, VERY expensive. I would think it has to be a non air dry type of bonding or it could take forever to cure.

a more practical solution would be to steel strap the CRT but, again I have no idea of the details on how to accomplish that. I suppose the roundies are less of an issue on the need for some kind of implosion protection, but that is just a guess.

[N2IXK]

Originally Posted by Dave S

Hmm, now I'm wondering if reinstalling the safety glass without it being bonded to the face of the CRT makes it less effective?

My understanding is that the front faceplate itself is just a piece of glass, sometimes tinted. The "safety" part comes from being bonded to the tube face with the clear resin, forming the glass/resin/glass sandwich usually referred to as "safety glass".

This bonded faceplate system was one of several methods of integral implosion protection. By removing the bonding resin, you are essentially defeating this protection. The separate faceplate may not be sufficient to contain the damage should the tube behind it implode.

With the litigious society we live in , I would be very wary of performing one of these "cataract removal" procedures on a set that was going to be sold or put on public display.

[DaveWM]

Originally Posted by N2IXK

With the litigious society we live in , I would be very wary of performing one of these "cataract removal" procedures on a set that was going to be sold or put on public display.

Ditto

[Dave S]

Originally Posted by N2IXK

The "safety" part comes from being bonded to the tube face with the clear resin, forming the glass/resin/glass sandwich usually referred to as "safety glass".

That was the same conclusion I came to. I have no expertise in that subject, it was just me sittin' under a tree thinkin', but it sure sounds logical.

A whole new area of research for us in the still-using-them-decades-after-any-sensible-design-engineer-would-have-assumed-they'd-be-gone game!

[Findm-Keepm]

On the 25AXP22 that imploded on me, the safety plate acted just iike a windshield - broke into a million little pieces, all stuck to to the face of the tube. Mind you, the tube also broke into a million little pieces with a big whoosh, but no high-velocity glass shards. It was if I had broken a large glass jug, but with the whoosh of inrushing air.

Here's my only experience of an imploding tube, in 34 years of being in the TV repair arena:

http://videokarma.org/showpost.php?p...0&postcount=18