Weekend CRT Cateract remove

[DaveWM]

I would leave that little bit of green alone, not worth the hassle of removing the CRT from the set.

However if you really want to do it, the green is soft, almost like a jelly, a thin music wire with a couple wood handles to grab it with can be used to slice under the lens, kind of saw thru the goo. Its a pita to clean up, very sticky gets everywhere, wear some old clothes...

[AiboPet]

Oh yes Nelson. Old TV sets that had Atari 2600 systems connected to them....or used as security monitors will have this burn-in if they were like that for a LONG time or the contrast was really high.

The BEST example of this is to go find an old Pac-Man arcade machine and turn it off. The "maze" on almost every one of 'em are burned in. You just don't usually see it unless the tinted glass isn't covering it, or you are servicing it and put up a blank raster.

This also is the biggest drawback to plasma sets.....super high contrast, and watching material with "bars" either top to bottom (letterbox) or side to side (SD)....WILL start to burn them. I even have a Viewsonic LCD that did the same thing. It's not a "burn" in LCD...it's called "persistance" and has to be exercised out.

MAYBE sunlight COULD do this, but it wouldn't be too obvious unless you did something weird like blocked HALF of the CRT from sun. My only curiosity is if all this HEAT does something to the phosphors...or the mask.

And Dave. That "string or wire with handles" is an old trick for us who play with customizing cars. You use a similar setup to cut through the 3M adhesive that holds something like the "Kia" emblem on your Kia Soul's bonnet. MUCH safer than heat guns and PRYING on paint...even with masking tape. I would imagine you DON'T want to be prying on or jamming tools between the CRT and a glass plate.

[vinljnkie]

In the early 80's when I was in high school I was in a computer explorer post through the Boy scouts at a local major carrier insurance company using their IBM 370 to learn how to program in COBOL (ugh!!). All the terminals in the company would display their company logo on the screen(all were green phosphor monitors) any time whey weren't being used. There was no screen savers or automatic power off for inactivity. Every single crt in every terminal I saw while I was there had a burned in image of that logo. I remember that computer being huge and it had 40 hard disk drives attached to it. Each one was the size of a top load washing machine!! Now I have a little 8GB flash drive in my pocket that cost me $10 that can probably hold as much data as 3-4 of those washing machines combined if not more.

[DaveWM]

yep the wire works well on the green since it can cut thru it, but on the RCA tubes the PVA (or what ever it is) is rock hard. I even tried heating some SS wire with a variac (I used to cut foam wings for model airplanes that way), even red hot the hard PVA was too much for it.

[Electronic M]

Originally Posted by snelson903

no im not thinking about the zenith its the magnavox i have that needs it.looks like i have a green pain in the caboose.

I disagree on Zenith cataracts being difficult. For someone like me who does not have a ton of patience Zenith style cataracts are more fun. The only parts that may be less enjoyable are that 'distilled essence of new vinyl' smell and the stickiness of the PVA, but they don't really bug me. All one needs to do is get the tube preped in the bucket, make the paddle and wire(no 18 single strand guitar string works well), do as I did in the below video, roll the PVA off the safety glass and tube(which sometimes don't go well on newer tubes),get tube face and safety glass spotless with Goof Off and Windex, and reattach the safety glass.


Here is a link to an album I created last summer when I taught my self the Zenith process(and ruined an RCA type CRT).
http://s1095.photobucket.com/albums/...nal/?start=all

[snelson903]

Originally Posted by Electronic M

I disagree on Zenith cataracts being difficult. For someone like me who does not have a ton of patience Zenith style cataracts are more fun. The only parts that may be less enjoyable are that 'distilled essence of new vinyl' smell and the stickiness of the PVA, but they don't really bug me. All one needs to do is get the tube preped in the bucket, make the paddle and wire(no 18 single strand guitar string works well), do as I did in the below video, roll the PVA off the safety glass and tube(which sometimes don't go well on newer tubes),get tube face and safety glass spotless with Goof Off and Windex, and reattach the safety glass.


Here is a link to an album I created last summer when I taught my self the Zenith process(and ruined an RCA type CRT).
http://s1095.photobucket.com/albums/...nal/?start=all

i think your answer should be more directed at mstaton, he was telling me im doing the asking. smile this is supposed to be fun !

[mstaton]

I was just saying the RCA ones are MUCH easier. I've only done 1 Zenith rectangle 22'. It's messy and nasty. I did it in the house during the winter and covered up the floor with blankets but I still managed to get a bit on the carpet. I sawed through it with guitar strings. Not as easy as you think since it want to restick itself after you cut through. I used some heat to help soften it up. The RCA PVA does not stick to things and yes it smells like a new kiddie swimming pool. The zenith stuff looks like boogers and it has a nasty odor. I'm sure it's not good for you either.

[snelson903]

Originally Posted by mstaton

I was just saying the RCA ones are MUCH easier. I've only done 1 Zenith rectangle 22'. It's messy and nasty. I did it in the house during the winter and covered up the floor with blankets but I still managed to get a bit on the carpet. I sawed through it with guitar strings. Not as easy as you think since it want to restick itself after you cut through. I used some heat to help soften it up. The RCA PVA does not stick to things and yes it smells like a new kiddie swimming pool. The zenith stuff looks like boogers and it has a nasty odor. I'm sure it's not good for you either.

man i guess everyone has had there own fight with pva to get so different response . i like the boogers analogy.

[mstaton]

Yours doesnt look too bad snelson, maybe leave yours alone, The maggie that is.

[snelson903]

Originally Posted by mstaton

Yours doesnt look too bad snelson, maybe leave yours alone, The maggie that is.

ill take your info ,when i restore the maggie i planed on doing it ,looking at that green margin will bother me i know it ,i want a nice sharp picture. i was thinking how about a large pan of water set it on a double hot plate then place the picture tube in it for a day maybe two ,water temp 120 -150 youll have to add already heated water time to time but that might soften the pva has anyone ever tryed that i wonder.

[NewVista]

This RCA Hi Lite difficult, didn't get it hot enough?
Was tapping in some wood shims and -Pop- safety glass
cracked as there is no adhesion in cataract but strong
adhesion in center. So be careful with shim pressure.

Strangely though, PVA just peels off smooth CRT face
once safety glass removed (Maybe vacuum really holding
it on convex surface)

The only upside for me is that I don't like the tint filter of
(RCA) safety glass and will like to see picture/colorimetry thru
modern clear soft safety plastic attach?

[mstaton]

The green stuff is not PVA, it's some other stuff. I don't think anyone here actually knows what it is. The water method probably wont work for that one. You will have to use the hotwire method or just try to slice though it carefully. You will need a lot of paitience. Don't do it indoors or your wife will put you in the doghouse. LOL

[snelson903]

Originally Posted by NewVista

This RCA Hi Lite difficult, didn't get it hot enough?
Was tapping in some wood shims and -Pop- safety glass
cracked as there is no adhesion in cataract but strong
adhesion in center. So be careful with shim pressure.

Strangely though, PVA just peels off smooth CRT face
once safety glass removed (Maybe vacuum really holding
it on convex surface)

The only upside for me is that I don't like the tint filter of
(RCA) safety glass and will like to see picture/colorimetry thru
modern clear soft safety plastic attach?

you probley have allready thrown away the old pva material ,if you still have any you could run some control experiments on some samples ,i would like to see what different solvents or basic water base alcohol's have any effect on the pva or just see what its made up of ,you never no some everyday household products could desolve it. it cool to find something that wouldnt hurt only the pva .the best samples would be taken from the center.

[ctc17]

Once the bonding agent is removed the safety glass becomes purely cosmetic. Remove only if absolutely necessary .

[NewVista]

Originally Posted by snelson903

thrown away the old pva material ,.

Still have plenty , PM if you want sample