How to fix loose CRT base - CTC11-12's
 

Ive got three tubes with different issues but all have a loose base. The '72 RCA colorama 21FJP22 that had its base skirt busted off goes first. Ill start by carefully extracting the solder from the pins of a donor base off a dead Sylvania 21FK and then double extra careful removing the busted-in-half base on the tube under restoration. I do not feel like re-soldering a lead busted off at the glass

Now what do I do? It needs to be non conductive, heat-resistant yet bond glass and phenolic. I saw a thread about a recipie for the crunchy caramel-colored glue-filler somewhere:scratch2:

I used clear nail polish on a tube before.

I use Permatex Flowable Silicone 81730 Windshield & Glass Sealer.

https://www.farmandfleet.com/product...ss-sealer.html

Old thread with recipie here:

http://www.videokarma.org/showthread.php?t=261452

You might want to scale down the proportions somewhat! :)

jr

Thanks for the suggestions. Nail polish sounds interesting also. Non acid seems like its also called sensor-safe on the silicone stuff.
Checking on availability with a chemist now...have to scale down weights on those ingredients for the goo, Ill sure try it.

I can understand being curious about the old glue recipe from a historical viewpoint, but why would you want to replicate the same stuff that is now falling apart and causing problems?

I'd use a modern product. Some things actually HAVE gotten better during the last 60 years :)

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

True, I would not think repeating the same formula obtains a different result. I am hoping that there are no heat and conductivity issues. The glass sealer Bob recommends was available at an auto parts franchise locally.

I plan to drill 3-4 tiny holes around the circumference to inject the stuff.