I got it! I got it!

[Kiwick]

Originally Posted by bgadow

Some of those tubes do not use PVA but instead have the safety glass seperate with a rubber gasket. I have a couple like that, including a 25MC30 Zenith, but have not had them apart to see just how it fits. It may have only been done on the standard models; maybe the anti-glare tubes were bonded?

I'm wondering why American CRTs used separate or PVA bonded safety glass lenses until the late 60s, while most European sets made after 1964 had CRTs with the modern "tensioned rimband" type of integral implosion protection and did away with any kind of safety glass in front of the actual CRT's face...

Maybe the separate or bonded safety glass was a legal requirement in the US back then?

Francesco