repairing broken tube keyways

[J M Fahey]

Aha! We have a good range of CA glues here with different names. It was the water activation that stumped me. Thanks Enzo

Itīs the common one , and "water activation" is the standard hardening method, only it does not take actual w-a-t-e-r as in a house hold tap, ambient humidity is usually enough.
If cold and dry weather, (typical Winter conditions) some people blow their breath on parts to be krazy glued, but in any case, activators exist which are sprayed on the joint, before or even after glue is applied.
Once it starts hardening, it goes all the way.

Didnīt know about the activating stick, but it makes sense.

Spray activation is often used in speaker repair.

[christarak]

CA or Super Glues typically have a maximum operating temperature of 80-120°C, which may not be enough for (power) tube bases. I'd go with 200°C epoxy.

Yep. I didn't know that. Thank you, Helm.

[christarak]

Thanks for that minim. I hope you enjoy the USA. I used to do shows in the USA and have been there many many times. I proposed to my fiancee in Central Park on my 60th birthday. The USA is a special place for me.

[Chuck H]

...some people blow their breath on parts to be krazy glued,..

That's one I picked up from watching detective shows. Something about a method for recovering fingerprints that involved the protagonist heating "Super Glue" in a plastic bag with the object to be fingerprinted and then breathing on the surface to harden the deposited vapor. Remembering how readily Super and Krazy glues bond skin I just put it together. I commonly "HAaaaa" on the joints to be glued now because it seems to improve the result.

But I think Helmholtz must have it right because while I already have trouble gluing some hard, resin type plastics with CA I have more trouble when heat affects the finished glue joint. This is probably what I'm remembering when I tried to Krazy Glue a tube base key back on some many years ago.