Zenith 29JC20 21"--cataract and convergence

[Electronic M]

Originally Posted by WISCOJIM

That was probably true for CRTs that were less than 10 years old. My experience with 40+ year old CRTs tells me that the laminate has dried out completely and is much harder now, and a wire will need a lot more force making it a tough pull, and a very risky one. And you definitely need to wear more than just gloves to use a wire on a hot tube.

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Definitely true of white cataracts the OP has fixed. The PVA of the white cataracts is very hard, especially where it has discolored...Pulling a wire thought it does not seem possible without causing damage to the glass. maybe when new and hot, but even that seems a bit off to me.

The green cataracts on later Zenith tubes, however, are very soft especially where discolored and I have been able to pull a cold wire through those on a chilly fall's night with only moderate effort.

I may have missed it but I do not recall Julian specifying which type of cateract was being dealt with so perhaps he was discussing the green type more common on Zeniths rather than the white in the set the OP has.