CRT cataracts

[MIPS]

I use acetone as well and just rub with a rag or newspaper until the surface clears.
Now mind you I do the heat gun and halogen lamp method which some people don't like but it turns the PVA into jelly.

[joe111671]

I have a 1962 Zenith b/w with a cataract. It's an RCA rebuilt crt and looks like a date code of 1971.

[AlanInSitges]

Interesting. RCA rebuilt a Zenith tube and got the Zenith cataract.

[Tom9589]

When the CRT rebuilders rebuilt bonded tubes, did they remove the safety glass first, rebuild the tube and then reattach the safety glass? Or did they just rebuild the tube with the safety glass attached? If the former method, what solvent did they use to remove the PVA?

As I recall the tension band/no safety glass CRTs were small, probably no larger than 19 inch CRTs.

[old_tv_nut]

The PVA could not withstand the heat of the rebuilding, so had to be removed.

The question would be, did they rebond the safety glass with PVA? RCA obviously did, but how about the small shops?

When I got my rebuilt 21FBP22 from Scotty, it did not have the safety glass re-applied. Doug Harland helped me salvage the glass from a dud and then tape it on the good tube, as is the usual practice for collectors.

[damen]

I had a friend who worked for Video Display Corporation back in the 1970s. He told me the tubes were heated up and the safety glass removed and usually discarded. They installed tension safety bands on most of the tubes they rebuilt. You could (and I did) special order a tube with the safety glass re-installed for an extra fee. I don't know what they used to reattach the glass, but one I still have has a cataract just like the RCA ones get.

[old_tv_nut]

Very interesting! I didn't know anyone installed tension bands on tubes not designed for them. Must have required some real knowledge of how to do it without breaking the tube in the process.

[ppppenguin]

Never mind not breaking the tube, how did they make sure that the tube was safe without a bonded shield? The original manufacturers of rimband tubes did extensive destructive testing to ensure that when the faceplate was broken no glass was hurled more than a few inches.

[old_tv_nut]

We have discussed before that the bonding of the safety glass (it appears) was not done to increase strength, but only to seal out dirt. The safety glass did provide protection, but more as an initial absorber of shock than reinforcing the tube, the same as a non-bonded safety glass.

[DavGoodlin]

Did Channel Master make better versions of 23EGP22's to do cataract surgery on, can I do it safely?

I picked up an Admiral combo a while back and the EG's cataract looks like an RCA's does. Not yellow

[colorfixer]

Originally Posted by maxhifi

I tried goo gone, acetone, wood stripper, lacquer thinner, paint thinner, as well as soap and water. The most effective thing was just repeated scrubbing until every last trace was gone. I'm kind of afraid of how toxic an actually effective solvent would be! Good thing is, this isn't exactly a job I have to do often.

What about toluene, benzine or even good 'ol gasoline?

[ppppenguin]

Toluene and especially benzene are toxic. Don't use benzene unless you really know what you are doing.

I don't know about US usage but in UK and Europe "benzene" is C6H6 cyclic aromatic while "benzine" is more or less a very light fraction of gasoline, largely straight chain alkanes. Much less toxic than benzene.