RCA cataract removal
 

I'm doing an experiment on RCA cataract removal. I took the 25XP22 out of my CTC-40 tonight and replaced it with a Sylvania 23VAJP22 rebuilt tube. It looks really good in the set. I put the cataracted tube in the bathtub with water. I've seen videos where people put them in water, and after a while, the cataract fell right off. I'll report back with my findings.

YMMV...Mine sure did! I had the same tube out of a CTC-25 it sat in water for about 2-3 months. All that happened was the mounting hardware rusted.

I have no idea what YMMV means. I had to use the mounting hardware to mount the Sylvania CRT, so no problem there.

YMMV=Your Mileage May Vary.....Google is good for acronyms and text message style gibberish.

The water never did a thing to loosen the glue on mine....All it did was invade where the glue had always been bad...

Interesting. In the video I watched, the entire piece of PVA came off in a big sheet even where it had not delaminated yet. Maybe you didn't let it sit long enough. It was an RCA tube identical to mine.

How did you get a 23" picture tube to fit into a 25" TV? :scratch2:

25XP22 is a 23" tube.

I thought the first two digits of the picture tube number indicated the size of the tube? e.g. 25xxxxx meant it was a 25" picture tube and 23xxxxx meant it was a 23" picture tube and 19xxxxxx meant it was a 19" picture tube.

That's correct. Before ~1970, manufacturers lied about the size. The government made them tell the truth.

In about 1970 or so the Federal Trade Commission came up with a ruling that said the advertised size must match the VIEWABLE part of the picture tube and not the overall diagonal measurement of the face. This cut down the size of a 25" to 23". After the change 25xxxx became 23Vxxx. Later, bigger tubes came out that were 25Vxxx. The "V" is the key!

TUD1, you type quicker than I do!

The PVA (adhesive) seamed to vary a lot, and I guess it's condition after all these years matters, too. I first discovered water would work when I dug out an old RCA round tube that I'd left sitting out in the woods for a number of years. The PVA had turned to jelly. I did one in a kiddie pool and it worked after 2-3 weeks, though still took some prodding. Others haven't responded nearly so well, especially the green type used by Zenith and others.

23V=25" tube. You have a 23VAJP22, never seen a 23AJP22, just the 23VAJP22 and a 25AJP22.....

23VAL/VATP22 were standard tubes in the 80s to replace the 25AP/XP22 CRTs.

By current FTC standards a 25XP22 is a 23 inch crt as in 23VAJP22. The "V" is to show current standard of viewable area. All the best, Tom.J

IIRC the government put the viewable area law in place in 1968.

I've put that tube in for the longest time I'd heard used. It belonged to a client so I could only wait so long.

Zenith CRTs can be done cool, safe, and reliably by cutting the soft glue with a guitar string....I'll take a dozen Zenith cat removal jobs over one RCA any day.

Is the screen cover usually glass or plastic on these sets? I've honestly never seen one in person. I know they're bonded with clear... adhesive or whatever, but that's it lol

I'm not aware of any plastic safety glasses. But then, there might be some out there.

Every bonded-to-CRT-face safety glass I've seen was glass....I've seen plastic safety glass too but as a separate piece from the CRT usually mounted to the cabinet separately.

It can take MONTHS of water soaking, really depends on how bad it is to start with (talking RCA type bonding).

I have one that has been out out side for well over a year, maybe 2, its in a foam packing case (the kind it was sold in as a rebuild). I have a funnel that catches water and drains into the face area. the pins and anode are covered in grease to prevent corrosion. I dug out some of the bad plastic to help trap the water.

I was tempted to just bury the face in the dirt (with a soft towel to protect the face) and let the microbes have a shot at it.

I don't think water will do much. Solvent would be a better bet. Diesel and kerosene are pretty safe, stable, and won't really evaporate. Dunno how good it would work, either, though. I'd imagine acetone would be the absolute best. It'll eat through damn near anything... but it's as flammable as gasoline, and it'll evaporate after a short time. It'd need to be in a sealed container, with a vent, and stored outside away from buildings and flammable things.

Have you read my name?

Or, you know, you could do THIS.

My Heathkit GR-370 came with a RCA Hi-Lite 25BCP22, unfortunately pretty much shot. I didn't know what to make of it, I couldn't see where separate safety glass was attached and the tension band was held on with bolts. The tag said it had integral implosion protection. Such a CRT seems very odd to me.

water works just takes time, need to be patient. heat gun works but not recommended esp on a rectangle tube. ALWAYS where safety goggles regardless of method.

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Glad for you Andy, hope you never have one go off on you.

Just checked the progress. Absolutely no difference. But that was only after 60 hours of soaking. We still have 2 months, maybe three, minimum.

what generally happens is the bond to the glass just weakens a bit. The adhesive will not dissolve at all. Again they are all different, worse is better as far as getting them unstuck. What you don't want to do is rush it, esp the critical moment of trying to wedge off the glass. I used wood clothes pins, dig out some of the plastic that is real bad and GENTLY tap them in all around the perimeter. What you are looking for is a very slight upward pressure that is even. If you try to hard the glass will break, then you have a much harder time getting the pins located with even pressure. Once the glass is broken its 10x harder. so again you must go very slow, on a hot day and it can take hours for the slight pressure to work its magic.

Safety gear is a must, I had one go off on me, blew BIG chuncks of glass, very sharp very pointy with an explosion that sounded like an M80 at about 8" away, and it was instant. I got lucky, had my googles on, still got some pretty decent size cut on my arms. heavy chunks went 30ft away.

Dang. Thanks for the warning. I've been handling these tubes pretty gently. I know they're dangerous, but hearing somebody's account of it really brings it home. I have poor eyesight, so whenever I'm doing literally anything, I have to have my glasses on. Not that eyeglasses are going to help on the event of an implosion anyway.

I removed the cracked safety glass from a NOS Channel Master rebuilt tube a couple years ago by soaking it.
It had no cataract at all except a bit of deterioration around the cracked area where air was able to get in.

It took a couple months face down in the tub with water above the level of the screen, since the glass was already cracked I just kept breaking off bits and pieces each week as the bond came loose.
If it had been in one piece I don't know if it could have been removed without breaking it, maybe after a year of soaking but not in two months.

I don't know if this was mentioned but, most bonded tubes have clear tape around the edge to keep air and moisture out, you need to remove it or cut it for the soaking method to work.

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REAL Good timing on this thread. My first Cat job was easy, and certainly not the norm. Full cataracts are a sight for sore eyes LOL

But now I am working on an original RCA Hi-Lite 21FJP22 from a GE roundie, now owned by another VK member. The cataract was advance to the point where only a 15" central circle was still fully attached. PVA or polyvinyl acetate supposedly only softens in water or methyl alcohol.

I used wedges like Dave says above, but once you crack the glass its a PITA (BAM! and it happens instantly). I was definitely not patient so Ill pay the price of robbing another CRT of it's faceglass, which HAS detached 100% :)

So far, I have been using the known dry methods, heat-gun, full-time heating pad-which I highly recommend, scraper razor blades cedar shims. and finally waxed dental floss (NOT ribbon floss) to keep the faceglass warm, chip away at softened the PVA.One I busted the glass, I had to wedge it out in pieces, basically inducing cracks with 2-minute intervals of 2-3" from the heat gun.

Once I was down to a 4" piece, I stopped using the heat gun because I did not have a good way to shield the adjacent CRT glass. This morning it took only a razor blade wedge and floss to pop off the last card-sized chunk of safety glass.
Below is a picture of what I have been working on over the last week. BTW- a 5 gallon bucket is great at protecting a tube like this. But for a 25XP22, I might opt to build a stand out of 2x4's.
Attachment 193552

Fortunately I too must wear glasses at all waking hours BUT safety goggles are the best practice for all of us when handling these tubes, even newer ones from the 70s onward.

Tom, Do I recall you passing some controlled current thru that guitar string to speed the process, like from a car battery:scratch2:

I initially* designed my rig to be capable of that, but did not pass any current when I did my successful Zenith type cataract removals. I initially experimented with current, but found the wire would develop hot spots, loose tensile strength and snap well before any significant progress would be made.
I've found it works best with NO current running through the wire and the wire at ambient air temp. I've also found it unnecessary for the tube to be warm...Back in fall when it was something like 45-65 F outside at night I did a guitar string zenith cat removal with the tube at ambient temp and the wire at ambient temp and it worked fine.

Make sure you attach the wire solidly to your pull handles, and to use something more sturdy than paint stir sticks. The glue will try and hold the wire/provide a good amount of resistance to pulling so it takes a good bit of arm strength.

http://i1095.photobucket.com/albums/...actremoval.mp4

*I've long since removed the current supply from the early guitar string cataract removal rig in my video.

The guitar string method is meant for the green halo Zenith style cataracts, the white moldy RCA style is unlikely to respond well to the guitar string method.

Great, I have two Zenith 25's that will need done. That yellow tint around the edge really makes the color look awful on those. Not Acceptable!

Pretty sure how rebuilder did it has come up before. that have industrial size ovens that can heat up the entire tube very evenly, to the point where the glass just lifts off. The issue with the heat gun is presumably un uneven heat causing stress for un equal expansion of the glass. I think the roundies are generally safter than the rectangles. Later rectangles had safety banding that would compress the perimeter. I the perimeter cant expand, then the tube can not explode along the perimeter, just inward from the implosion. After having one go off on me I tend to not mess with it anymore. just look for a decent CRT and live with it. Oh one more thing, if you are using heat clearly do not use a damp cloth to cool it down, again rapid uneven heat and cool is not what you want.

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

check out the burnt shadow mask..

Sony even patented the process. Rauland had been using it for years, but never sought a patent. I don't know if there was ever a patent fight, but both of them used the same process - heat it up.

PVB used in the first rectangular tubes is impervious to water. I'm sure that if someone knew the exact brand of PVB, a solvent is readily available - whether it be ammonia, acetic acid, some alcohol based solvent, or some hydrocarbon solvent.

The same PVB is used with early automobile windshields where they bonded the safety glass to the oven glass and needed an optically clear adhesive.

https://en.wikipedia.org/wiki/Polyvinyl_butyral

BLASTED! Here's RCA's method...

So basically they sandblast the safety glass until it doesn't exist anymore?

https://dl.dropboxusercontent.com/u/...ms%20legit.png

The water soak method is already showing sure signs of progress. Looked at it again today, and I was able to easily remove two huge chunks from the corners. I gently put some clothes pins in, and I could see where it was starting to come apart more.

leave it soak for a couple weeks (or months since its still cold out). Summer time is best for doing the removal, you put it out in the sun, put clips all around the perimeter, just a little bit of pressure from the clips bearing on the glass with as much contact area as possible. Slowly the glass will begin to let go, you can see the de-lamination progress as shadow lines will form on the face of the crt. As this happens the clips will get loose, tapping them in gently until just firm and walk away. The process can take hours. Best to do when its at least 90f outside in full sun. the most important thing is not to get impatient.

Had a good idea today while I was burying the mouse I finally caught. I dug a hole in the ground, put a tire on top for safety, and voila, poor man's cataract removal studio. I'm going to get a heat gun one of these days and start doing cataract surgeries that way. Water is taking too long.