Greetings everyone.
I have a 5Z3 rectifier tube with a loose glass envelope to base.
Would gas be a negative factor in this tube? and what is the method that would secure the envelope to base? glue?
Thank you,
Vinny A.

:Greetings everyone.
:I have a 5Z3 rectifier tube with a loose glass envelope to base.
:Would gas be a negative factor in this tube? and what is the method that would secure the envelope to base? glue?
:Thank you,
:Vinny A.
:
Hi Vinny; Test the tube,if OK just use a LITTLE crazy glue around base, or buy a new tube

Bob, tube tests great strong, I do not have a way to test for gas in this tube. Thank you for the info.
Vinny A.

wouldnt the gas make the tube glow blue or purple inside? thats what i would check any ways

:Bob, tube tests great strong, I do not have a way to test for gas in this tube. Thank you for the info.
:Vinny A.
:

A loose base has no effect on the tube, as long as you don't pull on the glass to get it out of its socket.

Cyanoacrylate adhesive has been known to crack glass envelopes.

I find that super glue won't hold up to heat, more than anything. I've never experienced a cracked envelope. You might try Permatex.

This has been done over and over again. A little Elmer's glue, diluted 1:1 with water, and allowed to dry for a couple of days standing up on a tube socket preferably on top of your furnace, should do fine. After that, sweat the pins with your iron and add a little solder if needed , clean it all off, and you should be good to go.

:I find that super glue won't hold up to heat, more than anything. I've never experienced a cracked envelope. You might try Permatex.
:

Elmer's does work. Forgot about that. It holds up to heat fairly well, too. It can burn on the plate caps of HOTs.

I have yet to try Permatex on a tube base. I have used it with exhaust manifolds, and it remains flexible and holds even after years of use. It might work for a tube, even under high temperature. You might prefer gray to orange for aesthetic purposes.

It's amazing how many uses there are for Elmer's, though. It's a great glue!

T.

:Greetings everyone.
:I have a 5Z3 rectifier tube with a loose glass envelope to base.
:Would gas be a negative factor in this tube? and what is the method that would secure the envelope to base? glue?
:Thank you,
:Vinny A.
:

:
:Hi! Vinny,
I had the same question when I first started with tube radios. Some day when you have a dead glass tube remove the base to see what's left. You will find the glass envelope sealed to wire leads at the bottom. That part is hidden by the base. A loose base has no effect on the vacuum inside the tube. The base does not seal the glass envelope.
Bob Masse
:
:

::Greetings everyone.
::I have a 5Z3 rectifier tube with a loose glass envelope to base.
::Would gas be a negative factor in this tube? and what is the method that would secure the envelope to base? glue?
::Thank you,
::Vinny A.
::
:
::
::Hi! Vinny,
:I had the same question when I first started with tube radios. Some day when you have a dead glass tube remove the base to see what's left. You will find the glass envelope sealed to wire leads at the bottom. That part is hidden by the base. A loose base has no effect on the vacuum inside the tube. The base does not seal the glass envelope.
:Bob Masse
::
::
:
Bob,
Good info to post, I read this in a book Terry Decker sent to me. Had a tube i was sure was leaking, bought another tube to try out, waste of money. Now have a spare tube. As long as you pull the tube from the base you will not damage the tube.
Mitch

If a tube does leak, it will be in a matter of seconds before the pressure inside of the bulb is the same of that outside of the bulb. When a tube is cracked even slightly, it usually takes less than a minute to fully fill with air, and at this point the filament won't light at normal voltage. It will be very apparent.

The gassy tubes you see with a purple glow inside aren't gassy from a leak, but rather from gases that were trapped in the metals (and possibly glass) within the tube that were released by some thermal/chemical action within the tube.

T.

Wow guys, thanks for all the great responses. A nice learning post for someone like me. I have a handful of duds in my tester to check out.
Thanks again,
Vinny A.

This may have been mentioned above as I did not read all the comments. I have used super glue since it has been on the market on hundreds of tubes without one problem. Mike...

:Wow guys, thanks for all the great responses. A nice learning post for someone like me. I have a handful of duds in my tester to check out.
:Thanks again,
:Vinny A.
:

:If a tube does leak, it will be in a matter of seconds before the pressure inside of the bulb is the same of that outside of the bulb. When a tube is cracked even slightly, it usually takes less than a minute to fully fill with air, and at this point the filament won't light at normal voltage. It will be very apparent.
:
:The gassy tubes you see with a purple glow inside aren't gassy from a leak, but rather from gases that were trapped in the metals (and possibly glass) within the tube that were released by some thermal/chemical action within the tube.
:
:T.

The manufacturer of the tube puts a thing called the "getter" annd it is fired after all of the air is sucked out that can be sucked out. Then the getter is fired, and it deposits a silvery looking deposit on the glass inside the tube. As long as there is a vacuum in the tube, the getter is silver. It will turn into a white powder if it comes in contact with air.
Lewis
:

The more modern brownish getter, usually put in place with an inductive ring, will turn white immediately after being exposed to air. However, the older silver getter, usually boiled in place from a small square of metal with a dimple for the chemicals to sit, or a cup shaped device also designed to hold the chemicals, will remain silver long after it has been exposed to air. There are also tubes in which no device is placed for holding the getter before it is activated. In any case, all tubes with a silver getter will not change immediately after being exposed to air. I have seen this getter stay silver for years.

T.

I believe that the more modern getter, due to its fast acting properties, does a better job of collecting gases that happen to escape into the vacuum during the tube's life, which is why it seems that all tube manufacturers switched to this form of getter. The other kind of getter I believe only really does its work while the tube is very hot during the evacuation process.

T.