Cataracts repair gone wrong........

[Eric H]

I've said this before so at the risk of sounding like a broken record...

When you remove the PVA from a CRT and reattach it with a bit of tape or Silicone around the edges you are essentially using a tube with ZERO implosion protection.
In fact it might be more dangerous because in the event of an implosion you now have a thin safety glass that will shatter and fly about as well as the tube itself.

I realize of course there aren't really any options and the risk of a spontaneous implosion is slim but it could happen.

[andy]

...

[jshorva65]

Originally Posted by andy

A tension band is similar to a mounting band, but it's under much higher tension, and it's not removable without cutting it. The idea is that if the screen breaks, the band will compress the pieces together so they will stay in place. The mounting ears are usually welded to the tension band, or under the band. If you need to remove them, cut them off (very carefully) instead of cutting the tension band. If you cut off the tension band, you would have to use a separate safety glass since the band was what provided implosion protection.

I've never tried it, but I've heard that a CRT will shatter if the band is cut while it's still under vacuum.

A shop in my hometown (which, fortunately, closed years ago) was well known for its hack repairs. At some time, well over 20 years ago, one of their technicians cut a rimband to attempt to fit a tube with rimband-secured mounting lugs into a set where a different mounting scheme was required for the CRT. I heard about this from one of that shop's other former technicians. As the story goes, the tube began to make an ominous clinking sound, the tech bolted out of the room and shut the door. Moments later, KABOOM!!! I was told the noise sounded like a shotgun blast, and that large shards of glass had flown under such force as to have become lodged in the drywall. The purpose of the rimband is to exert a force around the perimeter of the faceplate which acts against atmospheric pressure upon the faceplate (by tending to bow the curved faceplate outward more) roughly like the strings of a guitar and neck truss rod produce opposing forces acting upon a guitar neck. The force of the rimband around the curved faceplate produces a component of force acting outward over the faceplate surface, opposing the inward force due to atmospheric pressure. Without the rimband, the action of the counter-force is lost, and the full force of atmospheric pressure acts with far less force counter-balancing it than the manufacturer's design team ever intended. If the tube does not implode immediately or within a matter of less than one minute, its structure is permanently weakened and extremely unsafe for use. NEVER cut a rimband under ANY circumnstances!!!