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    Now you see it...

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    j beede

    Posts : 316
    Join date : 2011-02-07
    Location : California

    Now you see it...

    Post by j beede on Mon Apr 07, 2014 12:01 am

    I like to clean the dust off of old tubes so I can inspect the condition of the getter and to improve their appearance. I was pretty surprised when I used a damp paper towel to wipe some vintage Mullard GZ-34s and ended up with "no name" rectifiers as a result. Hate it when that happens. The PAS 3 I am working on has the original Dynaco labeled 12ax7 inside. I tested the writing... sure enough it will wipe right off. I don't suppose there's a trick to cleaning tubes while leaving the labeling intact?

    peterh

    Posts : 642
    Join date : 2012-12-25
    Location : gothenburg, sweden

    Re: Now you see it...

    Post by peterh on Mon Apr 07, 2014 1:44 am

    The trick is : "don't wipe the tubes". Blow off dust and settle with that.

    GP49

    Posts : 718
    Join date : 2009-04-30
    Location : East of the sun and west of the moon

    Re: Now you see it...

    Post by GP49 on Mon Apr 07, 2014 12:13 pm

    Yes. Happens on Mullards often. Don't ask how I know.

    peterh

    Posts : 642
    Join date : 2012-12-25
    Location : gothenburg, sweden

    Re: Now you see it...

    Post by peterh on Mon Apr 07, 2014 12:17 pm

    GP49 wrote:Yes.  Happens on Mullards often. Don't ask how I know.

    How do you know ?

    sKiZo

    Posts : 1285
    Join date : 2013-04-01
    Location : Michigan USA

    Re: Now you see it...

    Post by sKiZo on Mon Apr 07, 2014 1:14 pm

    Hey now ... he SAID don't ASK!!   Mad  Laughing 

    The painted logos do get fragile over time - all those hot/cold cycles destroy the structural integrity of the paint. A slightly damp pipe cleaner or Q Tip - and careful attention to detail - no dribbling and light pressure - can work wonders. Eyeglass cleaner or windex is good. then follow up with a dry one, should protect the print. Do a good enough job on the majority of the tube, and the crud remaining in the logo area kinda sorta disappears into the background.

    I've also heard that you can spray a light coating of clear acrylic over the top of the logo to protect it. That's supposed to at least keep it in the same condition it was, but I'd think that would have a tendency to yellow over time. I'll leave it to someone else to experiment with that.

    PS ... I've also touched up logos with a white fine tip sharpie with decent results. Don't tell anyone ... that's cheating!

    GP49

    Posts : 718
    Join date : 2009-04-30
    Location : East of the sun and west of the moon

    Re: Now you see it...

    Post by GP49 on Tue Apr 08, 2014 10:23 am

    In my junkbox I have tubes that have lost their brand name logos but have their tube type number etched into the glass.  Mystery tubes...one has to look at the construction to guess at who made a now-nameless 12AX7A, for example.

    Then there are the Supermystery tubes where no lettering remains at all.  Some Telefunkens fit that description: a glass envelope with the tell-tale diamond moulded into the base, and nothing else.

    Well...he asked!!!  tongue 

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