Well today I tried to remove a cateract on an RCA tube. Here is the gruesome story in photos and words.

I started by gouging out some of the PVA so I could pry the glass up, but because I could not locate any usable wood at first I tried prying with a screw driver and ruined the safety glass. This was yesterday. I made some progress, but the sun went down and I decided to put it in a tray of water over night.
http://i1095.photobucket.com/albums/i469/ElectronicMemory/CRT%20cateract%20removal%20pictoral%20journal/DSCN0964.jpg

The next day I made good progress, but between the chip from yesterday and the uneven pesssure of the small shims cracks started to develop.
http://i1095.photobucket.com/albums/i469/ElectronicMemory/CRT%20cateract%20removal%20pictoral%20journal/DSCN0966.jpg

Eventually it got to the point that I could only chip the lense off with a screwdriver...
http://i1095.photobucket.com/albums/i469/ElectronicMemory/CRT%20cateract%20removal%20pictoral%20journal/DSCN0969.jpg

But even with the googles I was wearing the glass chips were too unpleasent to tolerate. The next thing I did was VERY STUPID (understand that my brain does not work much if at all in 97 degree heat). I took the sizzleing hot tube and put it back in the cool water!:nono: As I walked away I heard a ping and hissing/gurgleing sound, this is the result.:tears:
http://i1095.photobucket.com/albums/i469/ElectronicMemory/CRT%20cateract%20removal%20pictoral%20journal/DSCN0970.jpg
http://i1095.photobucket.com/albums/i469/ElectronicMemory/CRT%20cateract%20removal%20pictoral%20journal/DSCN0971.jpg
http://i1095.photobucket.com/albums/i469/ElectronicMemory/CRT%20cateract%20removal%20pictoral%20journal/DSCN0972.jpg
The bell and face cracked and I could not be sadder and madder at my self than I was was when I snapped that series photos, despite the small reilef that I was not injured in what could have been a violent implosion.
I think I learned a valueable lesson about thermodynamics from this tragety if nothing else.

The less disasterous less sucessful Zenith process is to come in my next post.

Tom C.

PS: what should I do with the RCA tube now?

And now the Zenith decat process.

I left the tube in the sun untill it was very hot and then tried to pull wire through the glue the wire went about 1 or 2 inches in before snapping.

I tried various thicknesses of wire both hot and cold as well as the one i setteled on. Which cold was able to go in about the farest distance before snapping.

I initally heated all the wires with a fillament transformer that, as the thickness of the wire went up, prooved to be too weak. I then managed to find the transformer that I wanted to use from the beginning. It is a transformer from a computer battery backup power strip, and this thing has got some cahonies (the low voltage secondary is wound with wire so thick that it is tough to bend).
http://i1095.photobucket.com/albums/i469/ElectronicMemory/CRT%20cateract%20removal%20pictoral%20journal/DSCN0973.jpg
http://i1095.photobucket.com/albums/i469/ElectronicMemory/CRT%20cateract%20removal%20pictoral%20journal/DSCN0974.jpg
http://i1095.photobucket.com/albums/i469/ElectronicMemory/CRT%20cateract%20removal%20pictoral%20journal/DSCN0975.jpg



This worked well, but the sun was going down (to the point where the work space was in shade) and the tube started to cool. I also had a hard time finding a place where the wire would melt the glue well. The wire was hot to the point that the glue would smoke when I would turn the voltage up, but the wire would stick to the glue and refuse to go in further than 2".
http://i1095.photobucket.com/albums/i469/ElectronicMemory/CRT%20cateract%20removal%20pictoral%20journal/DSCN0976.jpg

The following are my most important questions to those with Zenith cateract removal experience.
Is the glue on Zenith round tubes somehow harder to work with than the rectangulars?
And when one cuts a zenith cateract with a hot wire, is it suposed to be like a hot knife through butter? If not at what rate does the wire normally slice the glue? And how hard does one need to pull the wire?
How hot should the wire be?

Sorry for all the questions. I've never done a cateract before and I'm not sure what I'm doing wrong. I like restoring and collecting color TVs enough that I realize I have to learn how to do this or live with cateracts (which I'm sick of).

Tom C.

You need to use a Steel wire, like a Guitar string. Copper isn't strong enough.

I used Ernie Ball custom gauge 18p guitar string and hooked my batterie charger to a rheostat I think I put it on 6 volts and raised the power on the rheostat till the wire got hot and pulled it back and forth between the lens and tube and went all the way threw in less than 5 minutes I did heat the front a bit but it was not real hot.

Steel wire! (slaps forhead) I thought about getting steel wire when I bought the copper wire. I guess I should have acted on that thought.

Thanks.

Tom C.

you dont need to heat the wire, just pull it thru. The zenith that I did had adhesive that was more like thick gel.

Yea, not a good I idea to put a hot CRT in cold water, be glad you did not get hurt.

the key to the RCA is to soften the pva with an extended soak in water (weeks if not months), then you can pull about 1-2" of the pva out around the perimeter. then you put it out int the sun face up, small wood wedges (I used chop sticks) get LIGHTLY tapped in just till they are snug, then walk away for 15min, come back and tap them in some more (they should be loose) walk away again. keep doing this, if you look closely you should be seeing fissures forming in the PVA (the sun will cast a shadow thru the pva, help to make them show up. How quickly this will go depends on the heat of the sun, but as you learned the hard way, it takes pressure heat and time.

I used saftey wire for the zenith, pretty sure its stainless steel.

First thing...get that thing on the grass!

Use guitar string and screw it to two wood blocks. Let the face warm up and saw it back and forth and it will go right through. The hard part is cleaning that stinky green goo off both sides.

What was the rectangular crt? 25xx22?

I'm impressed that what little was left of the safety glass was enough to keep the crt from turning into a messy implosion. Just be glad you didn't get nailed in something like that.

I did my de-cataracting with a heat gun set on low and waved gently over the screen, starting in a corner and working my way inwards. Took me about 15-20 mins, and the glass popped free. Nobody likes that procedure, but it worked for me :dunno:

I don't think its a question of not liking using the heat gun, more an issue of uneven heating and possilbe implosion (using low and your technique prob has a lot to do with how safe it is). the deal with the sun heating is its gradual so we presumeably less likely to cause thermal stress (no proof yet, clearly not good to take a sun heated CRT and put in cool water).

there has been a couple reports of implosion using the heat gun, but then again it may be something else unrealated, just a theory on the cause of failure.

Perhaps it all comes down to technique used.


The water soak is prob the least stressful as no heat is involved at all. It just take a VERY long time.

when I did the sun thing I let it sit outside as the sun set, the assumption is again a slow cool down. no proof this makes a differenece, but so far so good.

The rectangular RCA CRT was a 22JP22 and was a replacement for a different number in a Zenith TV set I bought from miniman (who probably will not be happy after reading that).

I don't have grass that I can safely put the tube on. I live in an apartment building that allows pets, and many dog owners let their dogs run free. This means that I have to be outside to run K-9 interference. The best place to do the catract is just out side my garage where I can be in the shade while waiting for the sun to get the tube hot enough, run K-9 interference, and have electricity for the hot wire in reach.

Though the wire would go in some cold I had to pull very hard and it would seem to get stuck a short way in so I don't want to rule out hot wire untill I have sucess with the cold.

I've been using a 3 to 5 gallon bucket to hold the tube upright if anyone was curious.

I chose the round Zenith tube for my first Zenith cateract because unlike the 22JP22 it was not part of any set I own, but rather a spare I had laying around so if bad things happen I don't NEED to seek out a spare.

Dave, what do you mean by "safety wire"?

I have three other Zenith cateracts in sets that I either watch or am planing to restore so I intend to get this process down to a science.

Tom C.

I'm going to get some steal wire and try again today if I can.

Tom C.

http://en.wikipedia.org/wiki/Safety_wire

Scary. Glad you didn't get hurt.

My dad and I used to use an old Lionel variable AC train transformer and a nichrome wire on a bow to cut foam wing cores. I wonder if this same setup would work on these crt's. You can even setup a few pullies and a weight to pull the bow at a constant speed. Dave probably knows what I'm talking about. :D

I do indeed, got the same deal with the bows... lots of fun cuting wing cores.

That is why I had the wire in the 1st place (and a variac). fun thing about TV's is they don't auger in...
:D

I could not get Earnie Ball guitar string, but was able to get 6 of these steel strings for about 1$ each locally. It was too late/overcast to try today. Maybe tomorrow.
http://i1095.photobucket.com/albums/i469/ElectronicMemory/DSCN0980.jpg

Tom C.

YES! Thats what I used, will work great.

When I first read about cataract removal, and this was maybe 8 or 10 years ago, the main method being discussed was nichrome wire and a car battery. If I had some of the wire hanging around I guess I'd try it. I can tell you that I'm in no hurry to do another one. I did several with a heat gun that worked perfectly, before having a down-to-air crt break in half. In my experience, water works better on the Zenith/Sylvania tubes than the RCA.

I've finally got around to doing an RCA 21FJP22 and I started soaking it last night. This is an ideal time with the heat spell that we are having. It's a good tube and I'll let it soak for as long as it needs!

if you are soaking esp outside, I would recommend bagging the socket with a plastic sandwitch bag, with a couple dessicant pack in there, all held tightly closed on the neck with a couple rubber bands. I dont know for a fact, but I figure extended time in a humid enviroment cant be good for the pin wires.

if you are soaking esp outside, I would recommend bagging the socket with a plastic sandwitch bag, with a couple dessicant pack in there, all held tightly closed on the neck with a couple rubber bands. I dont know for a fact, but I figure extended time in a humid enviroment cant be good for the pin wires.

Oh no..it's safely inside a steel building/shop environment. But you would be right to be concerned about the pin wires!

Fortunately the DFW area doesn't suffer from higher humidities than as you would get from being more close to the coast.

here in central Florida EVERYWHERE is a humidity problem. I have mine on the back porch (covered and screened) that little kiddie pool is really getting a work out.

So close yet so far.
http://i1095.photobucket.com/albums/i469/ElectronicMemory/CRT%20cateract%20removal%20pictoral%20journal/DSCN0981.jpg

At the end there was a CD sized spot that had wet looking fingers around it like on RCA tubes, that went away when it cooled off (which was before I took the picture).
I burned through ALL 6 of the strings. Some failed quickly. All snapped within 2.5" of the handles. It is bothersome that towards the inside of the cateract the glue seems to dissapate too much of the heat to melt very well, while towards the edges and exposed parts of the wire the wire blackens/burns becomes brittle and weak and snaps a bit too easily.
http://i1095.photobucket.com/albums/i469/ElectronicMemory/CRT%20cateract%20removal%20pictoral%20journal/DSCN0989.jpg

Part of the reason for the lop sided removal was the glue not melting right at the beginning, the other part was that rocks were some how finding their way from the parking lot to the edge of the glue. Most rocks did not make it any further, but one or more did as you can see below.
http://i1095.photobucket.com/albums/i469/ElectronicMemory/CRT%20cateract%20removal%20pictoral%20journal/DSCN0987.jpg

Another problem that arose near the end as the shade invaded my work area was that the screws on one paddle pulled out and I tried to do without which cost me some usable wire.
http://i1095.photobucket.com/albums/i469/ElectronicMemory/CRT%20cateract%20removal%20pictoral%20journal/DSCN0985.jpg
http://i1095.photobucket.com/albums/i469/ElectronicMemory/CRT%20cateract%20removal%20pictoral%20journal/DSCN0986.jpg

A strange air pocket also formed, and can be seen above the large glare spot.
http://i1095.photobucket.com/albums/i469/ElectronicMemory/CRT%20cateract%20removal%20pictoral%20journal/DSCN0988.jpg

I will NOT be able to do more for about the next week which makes how close I came to getting it off without sucess all the more frusterating!

When I do get the safety glass off, what should I use to clean the glue?

Tom C.

Tom-

I am not clear; is this a Zenith CRT or an RCA? If it is a Zenith, you may just need thicker wires (and more patience/slower wire movement). If it is an RCA, and you only have a CD-sized remaining bond area, you might as well go ahead with the heat-gun process (after the CRT has been in the sun for a couple of hours, though). Patience has to be the key here; glass cannot break with zero pressure, so any break had to be from higher/faster pressure change than it can handle.

This is a Zenith tube (the roundy that is) I'm working on.

I was merely making color commentary on how the ZENITH tube formed a wet looking patch of pva that reminded me of what I've seen RCA types do.

Tom C.

Let it soak in soapy laundry detergent or salt water to loosen the green stuff up.

I have a simple but probably ignorant question on this subject. When these cataracted sets are turned on, do the cataracts show at all? I've seen some older color sets in the Goodwills & other thrifts that had cataracts, but never tried to turn them on. They are usually sitting in the middle of the floor, far from the nearest outlet. My oldest color set is a 1979 RCA ColorTrak mediterannean console with the push button electronic tuner. Still works, doesn't have a cataract. Granted the cataracts look pretty nasty, but is this a cosmetic fix or a functional one?

the light green ones are not too bad, esp in a darkened room, but yes you do notice them but I am in no hurry to get rid of them. The RCA white ones can be pretty bad, and the mold spores types are a real problem as the look like shot gun pellets all around the edges. The green tends to be very consistant, so somehow seems less objectionable

Sucess!!:banana::banana::D
http://i1095.photobucket.com/albums/i469/ElectronicMemory/CRT%20cateract%20removal%20pictoral%20journal/DSCN1048.jpg
http://i1095.photobucket.com/albums/i469/ElectronicMemory/CRT%20cateract%20removal%20pictoral%20journal/DSCN1047.jpg

I got home from vacation late yesterday and did not waste much time geting back to the task at hand today. I went to the music shop today and they did not have the exact guage I was useing so I went with the next one up and got ten strings this time in antisapation of breakage, but I did not have any breakage or even need to get the wire hot. It just cut through like butter!:thmbsp:
http://i1095.photobucket.com/albums/i469/ElectronicMemory/CRT%20cateract%20removal%20pictoral%20journal/DSCN1053.jpg

I was able to roll the warm sticky layer of PVA off of the lense with my bare hands, and then used windex with ammonia to get the thiner residue off. It only is effective on the thinner residue. The thick stuff is much less responsive, but is affetted by it.
http://i1095.photobucket.com/albums/i469/ElectronicMemory/CRT%20cateract%20removal%20pictoral%20journal/DSCN1049.jpg

All but the edges of the CRT showed the most dramatic change from repeated cleaning with wnidex.
http://i1095.photobucket.com/albums/i469/ElectronicMemory/CRT%20cateract%20removal%20pictoral%20journal/DSCN1051.jpg
http://i1095.photobucket.com/albums/i469/ElectronicMemory/CRT%20cateract%20removal%20pictoral%20journal/DSCN1052.jpg

I'm happy now!:yes::D

Now on to the next three tubes!:lazer:

Tom C.

Eeeuuuww !! That is Icky-Poo NASTY stuff...

Not as "icky" as poo(at least for me), but definitly more of a pain in the a$$ to clean.
It also smells better(sort of like new inflatable pool toy/air matress IMHO). What makes it such a pain is 1.) how got'damn sticky it is (it out does even my worst allergy day snot), and 2.) my early wire glue cutting attempts did a better job of pulling the glue out and spreading it all over the face of the glass and the side of the tube such that it is much tougher to remove than the the bulk layer on the inside of the lense (that layer I was more or less able to completely rolled off by hand).
Windex IS the MOST effective solvent for Zenith PVA that I have tried. Water will not even do the least bit of good when attempting to remove that gooey PVA from my hands, but the windex(with a pinch of scrubbing) gets it off completely.

There is still a good bit of that garbage left on the tube so I have more cleaning to do tomarrow. Wish me luck.

Tom C.

I'm quite relieved that our colour sets were not old enough to have bonded crts's with this problem. Some of my mono sets with bonded tubes have snail trail lines coming from top and bottom of the crt but when the set is going you don't even notice them. By the way what are those numbers on the bottom of the picture tube in the last photo?

When I first saw those numbers I was suprised that they were there.
I don't know their meaning, but I do know that all three roundy tubes I have are marked with similar numbers in the same spot. So it would seem that most manufacturers used them.

Tom C.

Time for an update. Today (technically yesterday) I did a second cateract on a rectangular tube, Letting the tubes sit in the sun extra long seems to eliminate the need to electrically heat the wire.
http://i1095.photobucket.com/albums/i469/ElectronicMemory/CRT%20cateract%20removal%20pictoral%20journal/DSCN1061.jpg
http://i1095.photobucket.com/albums/i469/ElectronicMemory/CRT%20cateract%20removal%20pictoral%20journal/DSCN1062.jpg
http://i1095.photobucket.com/albums/i469/ElectronicMemory/CRT%20cateract%20removal%20pictoral%20journal/DSCN1063.jpg
http://i1095.photobucket.com/albums/i469/ElectronicMemory/CRT%20cateract%20removal%20pictoral%20journal/DSCN1064.jpg
Again I was able to roll most of the PVA off, but was getting tired of the limited effectiveness of windex at removing the residue.
http://i1095.photobucket.com/albums/i469/ElectronicMemory/CRT%20cateract%20removal%20pictoral%20journal/DSCN1065.jpg
http://i1095.photobucket.com/albums/i469/ElectronicMemory/CRT%20cateract%20removal%20pictoral%20journal/DSCN1066.jpg
http://i1095.photobucket.com/albums/i469/ElectronicMemory/CRT%20cateract%20removal%20pictoral%20journal/DSCN1067.jpg

With that in mind I sought out someting better while at the hardware store for the double stick, and clear sillicone caulk that I've read is a good way to reinstall the safety glass.
And found this product which is much much better at getting the PVA residue off (though it almost seems to fog the safety glass in the process, but maybe the glass was that way from the beginning?).
http://i1095.photobucket.com/albums/i469/ElectronicMemory/CRT%20cateract%20removal%20pictoral%20journal/DSCN1084.jpg
I used that whole bottle and cleaned everything spotless except the round CRT(which I started to clean before running out).

I couldent get 1/4" wide 1/8" thick foam double stick tape, but if I cut this lengthwise and stack two or three high I belive it just may work. Is this a bad idea?
http://i1095.photobucket.com/albums/i469/ElectronicMemory/CRT%20cateract%20removal%20pictoral%20journal/DSCN1085.jpg

Will any caulk work to seal the safety glass after remounting, or is a speciffic type needed? This is what I plan to use. Is it the right stuff?
http://i1095.photobucket.com/albums/i469/ElectronicMemory/CRT%20cateract%20removal%20pictoral%20journal/DSCN1086.jpg

Tom C.

Well I finally got around to filming one of the removals I preformed and posted it here http://www.videokarma.org/showthread.php?t=251762 .

I also cleaned and reattached the safety glass and reinstalled the CRT. The set preformed about as well as it did before, but the HV droped to 5KV shortly after, the audio is buzzing, and there is no video or sound. Which screams power supply problem to me. I'm going to look further in to it.
This the set I speak of.
http://i1095.photobucket.com/albums/i469/ElectronicMemory/DSCN0744.jpg
I bought this from DRH4683 about three years back, and he has a youtube series on how he got it working so this is not it's first time having a repair video on the net.

I was also considering decating this set, but I don't really have time, want to preserve the 100% originallity(and yes it does work), and want keep the one remaining example of a Zenith cateract I have.
http://i1095.photobucket.com/albums/i469/ElectronicMemory/DSCN0250.jpg

Tom C.