I have an old 80 globe tube with a loose base. What is the best glue to use on it?

For loose tube bases or loose grid caps I use a clear 5 minute type 2-part epoxy. Any brand will do.

:For loose tube bases or loose grid caps I use a clear 5 minute type 2-part epoxy. Any brand will do.

I would NOT use epoxy on tube that become hot. The epoxy will get soft and very smelly for those tubes like the #80 that get very hot....I stongly reccomend super glue...

::For loose tube bases or loose grid caps I use a clear 5 minute type 2-part epoxy. Any brand will do.

:I would NOT use epoxy on tube that become hot. The epoxy will get soft and very smelly for those tubes like the #80 that get very hot....I stongly reccomend super glue...
:
:
:::For loose tube bases or loose grid caps I use a clear 5 minute type 2-part epoxy. Any brand will do.

Interesting. I have also been told that super glue gives off gasses when hot and not to use it.

Super glue is definitely contraindicated in tubes that get hot - don't use it!!! The coefficient of expansion of glass - and that of super glue - vary so widely that it can cause the glass envelope to crack and ruin the tube. Epoxy has problems too.... Try HiTemp RTV or Duco for hot tubes.....

::I would NOT use epoxy on tube that become hot. The epoxy will get soft and very smelly for those tubes like the #80 that get very hot....I stongly reccomend super glue...
::
::
::::For loose tube bases or loose grid caps I use a clear 5 minute type 2-part epoxy. Any brand will do.
:
:Interesting. I have also been told that super glue gives off gasses when hot and not to use it.

:::I would NOT use epoxy on tube that become hot. The epoxy will get soft and very smelly for those tubes like the #80 that get very hot....I stongly reccomend super glue...
:::
:::
:::::For loose tube bases or loose grid caps I use a clear 5 minute type 2-part epoxy. Any brand will do.
::
::Interesting. I have also been told that super glue gives off gasses when hot and not to use it.

Somewhere I read of using alcohol to soften the adhesive and then pushing the parts together. It might take some time to soften the adhesive though.
Dick

John, I don't really know the proper answer to your question but just examined JB Weld container and it says good (MAX) to 600 degrees F, twopart epoxy (Locktite) 120 degrees F, Super Glue had not temp range but said don't use on glass, use their rear view mirror adhesive (that may be to get you to buy a more expensive product?). Since, I believe, all the
above products are some kind of "plastics" I would think they would all give off a smell. The RV gasket material may not be as rigid as the others but should certainly be able to take heat. I guess, unless you get some authoritative response (other than people throwing rocks at each other) you'll have to make a judgment call and find out how it works for you. I have to say I'm intrigued by the alcohol softening the old cement. It that would work thats the way to go. You will have the original cement holding it that was designed to take the heat. I don't believe anyone offered a suggestion that they felt would not work or be safe, they may be wrong but not malicious. PL

::::I would NOT use epoxy on tube that become hot. The epoxy will get soft and very smelly for those tubes like the #80 that get very hot....I stongly reccomend super glue...
::::
::::
::::::For loose tube bases or loose grid caps I use a clear 5 minute type 2-part epoxy. Any brand will do.
:::
:::Interesting. I have also been told that super glue gives off gasses when hot and not to use it.
:
:Somewhere I read of using alcohol to soften the adhesive and then pushing the parts together. It might take some time to soften the adhesive though.
:Dick

So does anyone know what the original cement was that they used to hold the base to the glass envelope? I've had this problem and have just left them alone, making sure to grab them by the base when pulling them out. Mark from Kalamazoo

:So does anyone know what the original cement was that they used to hold the base to the glass envelope?

From the AWA journal;

This recipe for RCA's basing cement, yielding about 200 pounds of material, was "standard for all bases.":

Coarse marble flour 170 lb.
Orange flake shellac 19-1/2 lb.
Durite phenolic resin LR275-2 7-1/2 lb.
Medium-color (grade G) rosin 3-1/4 lb.
Denatured alcohol 9 liters
Malachite Green aniline dye 10 g.

I believe a similar cement is still available but I can't recall the commercial name. You may try muffler cement. It is a 2 parts resin similar to putty epoxy and its resistance to heat is sufficient for vacuum tubes use.

In wide world of radio repair and restoration, Mr. Berg is indeed the perfect reverse barometer..... If you do exactly the opposite of what he recommends - you might actually fix the problem!!!

:In wide world of radio repair and restoration, Mr. Berg is indeed the perfect reverse barometer..... If you do exactly the opposite of what he recommends - you might actually fix the problem!!!

Super glue will not work on a tube which runs hot like an 80, after a few heating-cooling cycles the glass will crack at the glue line. Epoxy will work but does get soft as previously mentioned. High temp silicone does work and comes in black. I have also used good old Duco cement without any problems. Most anything will work on tubes that do not run hot, just don't use Super Glue on rectifier or output tubes.

Dave

:Super glue will not work on a tube which runs hot like an 80, after a few heating-cooling cycles the glass will crack at the glue line. Epoxy will work but does get soft as previously mentioned. High temp silicone does work and comes in black. I have also used good old Duco cement without any problems. Most anything will work on tubes that do not run hot, just don't use Super Glue on rectifier or output tubes.
:
:Dave

I wonder if there is something in an automotive parts store for for the repair ofmufflers and tailpipes that might stand the heat??
Lewis

::Super glue will not work on a tube which runs hot like an 80, after a few heating-cooling cycles the glass will crack at the glue line. Epoxy will work but does get soft as previously mentioned. High temp silicone does work and comes in black. I have also used good old Duco cement without any problems. Most anything will work on tubes that do not run hot, just don't use Super Glue on rectifier or output tubes.
::
::Dave
:
:
:
:I wonder if there is something in an automotive parts store for for the repair ofmufflers and tailpipes that might stand the heat??
:Lewis

Indian Head Gasket Shellac,takes temp up to 350 degrees, works for me so far

A 6L6 runs about 480 F, some rectifiers run hotter, the shellac would melt away.

Dave

:Indian Head Gasket Shellac,takes temp up to 350 degrees, works for me so far

funny thing is,I've rebased 5u4's on 5z3 bases which might run as hot or hotter than 480 degrees.
i haven't had a meltdown yet In over 30 years.

but i generally started using indian head For rebasing 864's on WD11 bases, then went up to the hotter tube types.

although it says in specs max temp 350 degrees i have rebased many tubes that have run hotter.

it's less than 4 dollars a bottle to try and see for yourself.

I decided to do a little testing.It's no surprise that your gasket shellac stands up well, NoWool.I let my Philco 37-610 run for 4 hours at half volume.I used the temperature probe on my Fluke 179 to check tube temperatures.At the base on the 6f6g,the glass temperature averaged 150 degrees.At the hottest point of the tube,near the shoulder,it measured 220-240 degrees.Interestingly,the 5Y4 rectifier ran slightly cooler.The base averaged 130 degrees or so,and the hottest area a little over 200 degrees.

I was going to jump in and ask if any one ever measured temperatures but Michael solved that. I suspected the temp at base would be a lot less than at top of tube (heat rising and all) so anything that would take 200 should work except for grid caps. PL

:I decided to do a little testing.It's no surprise that your gasket shellac stands up well, NoWool.I let my Philco 37-610 run for 4 hours at half volume.I used the temperature probe on my Fluke 179 to check tube temperatures.At the base on the 6f6g,the glass temperature averaged 150 degrees.At the hottest point of the tube,near the shoulder,it measured 220-240 degrees.Interestingly,the 5Y4 rectifier ran slightly cooler.The base averaged 130 degrees or so,and the hottest area a little over 200 degrees.

For the most part I've had success with the brush on SuperGlue used mostly on grid caps. A few bases too from time to time.

Although I did find one tube ...just once...( 1 out of maybe 25) that had a clean line crack/hole all around the grid cap a little bit further down from the base of the cap.

But it hasn't deterred me from using Super glue.

Now if I knew of the perfect product... and it was relatively easy to use ( not like mixing a batch of epoxy) I would use it.

But in the mean time ... Super Glue does the job.

DID I NOT SAY ..LIKE 30 REPLIES AGo..TO GO WITH SUPER GLUE....Over all it works fine

:For the most part I've had success with the brush on SuperGlue used mostly on grid caps. A few bases too from time to time.
:
:Although I did find one tube ...just once...( 1 out of maybe 25) that had a clean line crack/hole all around the grid cap a little bit further down from the base of the cap.
:
:But it hasn't deterred me from using Super glue.
:
:Now if I knew of the perfect product... and it was relatively easy to use ( not like mixing a batch of epoxy) I would use it.
:
:But in the mean time ... Super Glue does the job.
:

condescending, arrogant. for a teacher you need to LEARN TO SPELL - its CHASSIS not CHASSIE, and watch the use of TO and TOO

:DID I NOT SAY ..LIKE 30 REPLIES AGo..TO GO WITH SUPER GLUE....Over all it works fine
:
::For the most part I've had success with the brush on SuperGlue used mostly on grid caps. A few bases too from time to time.
::
::Although I did find one tube ...just once...( 1 out of maybe 25) that had a clean line crack/hole all around the grid cap a little bit further down from the base of the cap.
::
::But it hasn't deterred me from using Super glue.
::
::Now if I knew of the perfect product... and it was relatively easy to use ( not like mixing a batch of epoxy) I would use it.
::
::But in the mean time ... Super Glue does the job.
::

:condescending, arrogant. for a teacher you need to LEARN TO SPELL - its CHASSIS not CHASSIE, and watch the use of TO and TOO......

----------------

He's a HISTORY teacher - not spelling or grammar (obviously).... however, with his continued bent toward loutish behavior, I do wish he'd become ANCIENT HISTORY on this forum....

Great Googly Moogly,let's all take a breath and count ten.
Someone mentioned "ANCIENT HISTORY", in a sense that's what this hobby is about let's not forget.
The hell with some attitudes ,we all know they make the person spewing the Nonsense seem Idiotic.
This is a pretty good topic, more important then some A-holes attitude.
let's please get back to the topic "Loose Tube Base" Not"A Screw Loose".
I have Tried crazy glue in the past,It held for some Time On some tubes and dried out on others ;
I think it might be a bit of fun expirimenting with some newer types of super glues and compare results.
Any suggestions or Brands worth trying?.
Also I wonder if there is any way to simulate Aging of the glue in these tests?
Because it seems There a few Types of bramds and types of glues,epoxys,etc that will hold but which will stand the test of time-lets say 5 years at least?

::condescending, arrogant. for a teacher you need to LEARN TO SPELL - its CHASSIS not CHASSIE, and watch the use of TO and TOO......
:
:----------------
:
:He's a HISTORY teacher - not spelling or grammar (obviously).... however, with his continued bent toward loutish behavior, I do wish he'd become ANCIENT HISTORY on this forum....
:

Well this is so funny, just get so of that stuff on TV. ya
know if it's on TV it must be true!
I just use a different tube myself.

:Great Googly Moogly,let's all take a breath and count ten.
:Someone mentioned "ANCIENT HISTORY", in a sense that's what this hobby is about let's not forget.
:The hell with some attitudes ,we all know they make the person spewing the Nonsense seem Idiotic.
:This is a pretty good topic, more important then some A-holes attitude.
:let's please get back to the topic "Loose Tube Base" Not"A Screw Loose".
:I have Tried crazy glue in the past,It held for some Time On some tubes and dried out on others ;
:I think it might be a bit of fun expirimenting with some newer types of super glues and compare results.
:Any suggestions or Brands worth trying?.
:Also I wonder if there is any way to simulate Aging of the glue in these tests?
:Because it seems There a few Types of bramds and types of glues,epoxys,etc that will hold but which will stand the test of time-lets say 5 years at least?
:
:::condescending, arrogant. for a teacher you need to LEARN TO SPELL - its CHASSIS not CHASSIE, and watch the use of TO and TOO......
::
::----------------
::
::He's a HISTORY teacher - not spelling or grammar (obviously).... however, with his continued bent toward loutish behavior, I do wish he'd become ANCIENT HISTORY on this forum....
::

Yes yes I posted this..me Peter G. Balazsy

:condescending, arrogant. for a teacher you need to LEARN TO SPELL - its CHASSIS not CHASSIE, and watch the use of TO and TOO
:
::DID I NOT SAY ..LIKE 30 REPLIES AGo..TO GO WITH SUPER GLUE....Over all it works fine
::
:::For the most part I've had success with the brush on SuperGlue used mostly on grid caps. A few bases too from time to time.
:::
:::Although I did find one tube ...just once...( 1 out of maybe 25) that had a clean line crack/hole all around the grid cap a little bit further down from the base of the cap.
:::
:::But it hasn't deterred me from using Super glue.
:::
:::Now if I knew of the perfect product... and it was relatively easy to use ( not like mixing a batch of epoxy) I would use it.
:::
:::But in the mean time ... Super Glue does the job.
:::

Yes, I am sure we all saw your reply:

...."I stongly reccomend super glue"...

...with it's gross misspellings...maybe we did not know
what "stongly" means..maybe we do not trust someone's
advice if being a "teacher" you are not attentive enough to even reread your posts for errors before
submitting your remarks. You just don't get it. You
have made many people, maybe not all, on this site
ignore you rather than respond to you because of your demeanor.