OOPS! How to Fix an Old Tube Cap?

[Winky Dink]

I'm in the chassis dust-removal stage of restoring a 1931 Airline console. I pulled the connector off a balloon-type 24 tube and I thought "Gee, look how they made these tubes! There's no metal cap--just a wire sticking out of....oops."

So, how do I replace the cap? I have 1/8 inch of wire from the tube that I can solder an longer wire. I'm guessing that if I desolder the separated cap and remove the goop, that there'll be a hole for the wire, and that after I can thread the elongated through the cap, fill the cap with new goop, reseat the cap on the tube, then solder the wire to the cap. (If I'm not making sense, then see the attached photo)

The question is, what kind of goop can I fill the cap with that will be adequately heat-resistant and adhere to the glass?

I've posted some pics on PicasaWeb:

http://picasaweb.google.com/coldrb/A...eat=directlink

[truetone36]

I did this same exact thing while working on a Silvertone R-101 a while back. I'm just going to replace the tube.

[bandersen]

Since you still have the old resin in the cap, I'd try a little super glue. It's not very heat resistant, but a 24 doesn't get very hot as I recall.

[Winky Dink]

Thanks for advice. The repair was much simpler than I anticipated. I just added a little bit to the terminal wire, scraped some of resin to ensure the cap would seat, used a little epoxy cement, and soldered the wire to the cap.

[Reece]

Happens all the time, and ya did good. Trick is to clean the stub of wire really well scraping with a knife, tin it quickly, ditto the new piece you are putting on, and solder them together in the blink of an eye. Keep the tube as cool as possible.

I really like that radio. The cabinet is in superb condition save for the top. Will have to refinish the top it looks like, but that's all for what can be seen in the pictures. That vertical dial with the skyscraper effect (dare I say "deco?") is very attractive, as is the diagonally matched veneer on the panel. The chassis is wide open underneath and easy to work on. The rubber "sock" on the back tube must mean it was microphonic. I think you got a winner, and I'm jealous!

[Wizard256]

Not the superglue!! This will crack the glass due to thermal expansion. Use acetone and shellac to rebond the old glue to the tube's glass. The Original paste was shellac and wood dust.

Cheers, Wizard