What's a good way to clean tubes w/o taking off the labeling?

[lochness]

I use water and paper towel (I do finish off with lens paper)...never broken a tube or removed the lettering...what the hell are you guys getting on your tubes that you need something stronger?

[TubeHead Johnny]

I use water and paper towel (I do finish off with lens paper)...never broken a tube or removed the lettering...what the hell are you guys getting on your tubes that you need something stronger?

You would be surprised how much dirt and grease accumulates on 40 or 50 year old equipment! And the heat just bakes in on.

[CarlyBoy]

Etch the tube designation on the bottom of the tube base before attempting any cleaning. A tube without designation is useless.

[anatech]

Hi,
How do you etch the number on? That sounds like a great idea for the pricey tubes.

I use water like lochness does. There are times I need to add some cleaning agent. The trick is to use a moist paper towel (torn down to what you need). Very little pressure and avoid the lettering.

Yes, often there is something on new tubes that requires more than just water to remove. Old tubes tend to get baked on stuff as Johnny says.

-Chris

[ArtG]

Buy GE tubes! Many of their tubes had the tube types etched into the glass, making it easy to clean them without worry!
The worst ones, from my experience were the Dynaco rebranded Telefunken 12AX7s. used mostly in the PAS preamps. The slightest rub obliterates the markings! Good thing the diamond was embossed on the bottom!

[astouffer]

I scrapped an old european tape recorder and just bringing it in from the cold caused a slight condensation to form on the tubes. That was enough to totally remove the lettering when touched. The tubes in question were all Philips Miniwatt.

As for etching the tube glass or octal base. My dad has some sort of pencil like scribe with a tungsten carbide point. Not sure where its from but something like that could easily etch glass.

Once you start collecting tubes its very easy to identify what type it is just by the internal structure. Of course trying to tell a 12AX7 from a 12AU7 can be tricky

[moray james]

I came up with this simple idea for a small company that cleans plates and grades tubes. Get a roll of the cheapest (so thinnest) cling wrap you can find at the grocery store. Slit the film so you have a section of the roll as wide as you want. Take six or seven inches of film and wrap the tube over the silkscreen print. This stands up to hot acid baths and cold water washing comes off easily and has zero impact upon the print. Will stay on untill you take it off. Give the film a good tight wrap.

[reenberg]

I once had a lot of small tubes, say 50 or 60 ( good tubes, telkefunken, bugle boy ect). They were all very dirty, so I put them into a bucket and poured some semi hot water over them.
ALL the print diapered, and most of them was impossible to identify. So take care when you clean them. I think some of the print need some ' baking ' before it really stick to the glass

[anatech]

Hi Moray,
I guess you're just covering the print area only then, all around the tube?

Philips were certainly the worst for disappearing lettering. Most times if you look at those tubes before even touching them, much of the lettering has moved around or is missing.

Too bad etching was too expensive for them to do way back when. That seems to be the only way to mark glass in any lasting way.

-Chris

[Poindexter]

Yah, my last acquisitions were large quantities of 6GK5 (240) and 6T4 (170), and these undesirable teevee orphans had sat around in some warehouse for forty years until the pins were unworkably cruddy.  Tarn-X is now my hero, but it's chemically very active, and you got to get it off there with soap and water and a water rinse.

I can now reliably report that if you get water (not the soapy one, just the rinse) even near the printed lettering on Mullard, Hitachi, or RCA tubes of that era, you can kiss it aloha.  Don't matter how gentle you are, it just swooshes away buhbye.

Hold on tightly, let go lightly.  I got nice clean pins.

Aloha,

Poinz