Cataracts repair gone wrong........

[drh4683]

Well, it finally happened. A complete disaster involving cataract repair. I have a 1966 motorola console with its original 23EGP22 with very bad cataracts. The tube was mint too, 100% emission low hours. The set had an unbelieveable picture from what I could see through the cataracts. Yesterday I attempted the repair using the successful heatgun method with the heat lamp. The cataracts had the "mold" like appearance like the RCA's, so I figured this tube would be easy.
After preheating the lens for about 45 minutes, the CRT was ready. I removed the heat lamp and turned on my milwaukee heat gun. I started right in the center edge of the tube. I kid you not, it was only 10-15 seconds later "BLAM" the entire CRT imploded like a bomb and threw glass shards all over my shop. Phosphour dust was everywhere like someone threw ashes in the air. It happend right before my eyes and was so fast I couldn't believe it. I didnt even have enough time to react, I still had the heat gun in my hand holding it like i was still heating the lens. When the lens imploded the glass was rejected in a horizontal plane. Fortunately, the CRT was in a horizontal position and the safety lens did its job.
To my surprise, absolutely nothing happened to me. Not even a scratch.
Even though Im so dissapointed this happened, I can't be upset because this did not fail due to careless technique. Ive never attempted cataract repair on an NVC Motorola tube. Obviously, I will be no longer attempt the heat gun method to CRT's. The 23EGP22 is a mechanically weak and not capable of accepting the extreme heat. The frit seal is up much higher twards the face of the tube than RCA or Zenith tubes. I think what happened here is the glass expanded and with the smaller glass surface area on the side, it expanded down to the frit seal, which failed leading to the implosion.


So now Im out of a perfectly strong 23EGP22 (which is as rare as a good 15GP22 in my opinion) is gone, I need to find a replacement. I cannot sub any other tube unless I have a motorola CRT conversion kit as the support brackets would need to be changed as well as a modified CRT bezel. So finding a replacement EGP is my only hope to bring the set back to life. As of now, its a mint condition piece of scrap.

Im going to be experimenting with chemical reaction to PVA to see what can be done in the future to separate the lens for the tube. The heat gun method, while proven successful in the past has its dangers and should be stopped. What was always feared has finally turned into a reality.