[drh4683]

My 63 zenith 26KC20 still has its original 21FBP22 with the typical olive green screen. I got the set from the original owners and they kept it in their clean attic since the 1970s.
When I got the set this summer, I was surprised to see that a 21FBP22 had a "decayed" or "catarac" look to it around the perimeter. It looked almost as if vasaline had been smeared around the lens from the inside.
Just yesterday, I decided to take apart my first 21FBP22 to see what I could do about cleaning it up. Like any crt project, it is very careful work and one wrong move is a disaster! After the chassis removal etc the tube basically simple to remove. However, it came out with metal framework around it. This frame mounted the tv to the cabinet and also held the lens against the crt. The crt had to be lifted out of the frame rather than just pulling it off the crt. I did this by supporting the 4 corners of the crt frame with 4 beta tapes to keep the face of the lens from contacting the surface of the workbench. The crt basically lifted out with the lens still attached. The lens is actually not bonded at all to the crt. Its actually a rubber gasket that fits around the lens and just presses against the crt and is held in place when the crt mounting hardware is reinstalled.
What I found was that the rubber gasket used a grease type material that was used to help make installation of the gasket easy. I pulled off the gasket. They are a very high quality rubber that flexes nicely, it does not age (dry rot etc) This greasy substance caused the haze to develop between the lens and the crt. im thinking this is because it was in an attic, which probably got pretty hot in the summer and just baked up there. Ive never seen this with any other 21FBP22 of its type.
The gasket cleaned nicely, did not leave a sticky residue after cleaning and fit back on the lens. After cleaning the crt and lens with windex and reinstalling, the set looks new. Threw out this experience, I also found out that the 21FBP22 actually has green phosphor, as the screen is green with the lens removed.
Now you can see the before and after pictures.

The point- Working on a 21FBP22 is way easyer than a 21FJP22!!! No heat gun, no special tools. Just be careful not to drop it!! I was nervous the entire time, as Ive experienced crt lens breakage. It took about 1.5 hours from start to finish.

In the first "before" picture, notice the dark tinge around the perimeter of the lens. Thats the evaporated gasket grease.