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    Old person - old Stereo 70 - new to all this - kindergarten questions

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    JamesD

    Posts : 1
    Join date : 2020-05-02

    Old person - old Stereo 70 - new to all this - kindergarten questions Empty Old person - old Stereo 70 - new to all this - kindergarten questions

    Post by JamesD on Tue May 05, 2020 4:24 am

    .

    - 72 y/o

    - been "into" audio since 1960s (McIntosh/Bozak/Benjamin Miracord!)

    - I was bird dogging some classical records about 15 years ago,
    and this nice old lady just wouldn't let me leave without this ST-70
    "It was my husband's, I have no use for it, won't you please take it."

    - But "life" dictated that it just "sit", here, for 15 years.  But now, the time has come.

    - My plan is to get Roy (I think, I hope) to VTA70 it (plus other bells and whistles)

    - But before I send it off, I need to do any/all cosmetic work to it that's going to get done.
    i.e., I don't want to be doing a bunch of cleaning and polishing around and on top of all of his new work;
    best to do all that now, of course.

    - Current Status - just dirty, hand oil-y, decades of dust and handling, etc.
    i.e., I see no signs of any rust or pitting.

    - So Far - I've taken the tubes out and the bottom off.
    The inside looks clean! and bright! and spiffy!
    EXCEPT - something or things "dripped" onto the bottom in the right rear corner, and the left front corner.
    Soft sticky stuff that came off easily with Goo Gone.

    - The bottom cleaned up nicely.

    - NOW, WHAT I NEED ADVICE ON:
    How do I approach cleaning that whole top.
    I am not going to be stripping out the board, all the tube sockets, transformers, power transformer, etc.
    Whatever I am going to do, I have to do AROUND all of the above.

    So I guess my two questions are:

    1- recommended materials and "substances" to do the cleaning (and polishing?)

    2- I think that I can handle cleaning and shining up the plated chassis (chassis? proper word?).
    Especially with some responses to #1 above.
    But how careful do I have to be working AROUND all of the things that are still mounted to the chassis?
    How careful do I have to be about getting the various solvents/cleaners/polishers I might end up using...
    - about getting these things ON the tube sockets and transformers, etc.



    I think I will stop here, and let any other comments or things I'm thinking about fall into place further along.

    Thanks in advance.
    I'm really excited about this little audio project.
    But I'm sorta in uncharted waters.
    And hoping to get some advice from others who have done this before, so's I won't have to "reinvent the wheel".  Smile  

    James

    .
    PeterCapo
    PeterCapo

    Posts : 794
    Join date : 2008-12-05

    Old person - old Stereo 70 - new to all this - kindergarten questions Empty Re: Old person - old Stereo 70 - new to all this - kindergarten questions

    Post by PeterCapo on Tue May 05, 2020 3:50 pm

    The original Stereo 70 top chassis and bottom plate have a thin nickel electroplate over steel.  Polishes can sometimes be considerably harsher than, for instance, automotive paste wax.  I once made the mistake of using a polish on a Stereo 70 chassis, and it etched it.

    I suggest either a thorough dry cleaning using a Swiffer, or a damp wipe down using either water or a mild solution with dish-soap, followed by a rinsing wipe with just water.  Dry it off right away.  You might also try some isopropyl, but if its water content is higher, then, again, wipe it dry quickly.  Then, when it is completely dry, finish with an automotive paste wax- should leave a nice shine on it.

    One of the problems with trying to clean the chassis is that the lettering can come off easily.  You'd need to work around the lettering very carefully.  It is not terribly likely the lettering will survive if you clean or wax right over it.

    No, you don't want to get cleaning or finishing substances into places where they doesn't belong.  Not good for tube socket contacts, for instance.  If you have any interest in keeping the original PC board viable, then don't let any chemicals (or anything else) get onto it, and don't strip the wax coating off of its bottom side.
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    wildiowa

    Posts : 223
    Join date : 2012-03-19

    Old person - old Stereo 70 - new to all this - kindergarten questions Empty Re: Old person - old Stereo 70 - new to all this - kindergarten questions

    Post by wildiowa on Thu May 07, 2020 8:30 am

    I often used regular rubbing alcohol and Qtips to cut through and loosen up old grime and dirt. It is cheap plentiful and works for most situations. After that you can use other products or even a soft cloth to finish up. You can also use it to start cleaning out the tube sockets pots and other components. Have you tried to fire it up yet?
    PeterCapo
    PeterCapo

    Posts : 794
    Join date : 2008-12-05

    Old person - old Stereo 70 - new to all this - kindergarten questions Empty Re: Old person - old Stereo 70 - new to all this - kindergarten questions

    Post by PeterCapo on Thu May 07, 2020 10:00 am

    Alcohol and other chemicals can be very bad for vintage pots or anything with phenolics.  For the pots, I suggest just vacuuming-out the carbon dust.  Please see here:

    http://store.caig.com/s.nl/ctype.KB/it.I/id.316/KB.215/.f

    http://store.caig.com/s.nl/ctype.KB/it.I/id.1828/KB.215/.f

    http://store.caig.com/s.nl/ctype.KB/it.I/id.1809/KB.218/.f
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    wildiowa

    Posts : 223
    Join date : 2012-03-19

    Old person - old Stereo 70 - new to all this - kindergarten questions Empty Re: Old person - old Stereo 70 - new to all this - kindergarten questions

    Post by wildiowa on Thu May 07, 2020 10:22 am

    Yes De-Ox or similar product is always the first choice. Recall many nights on the road miles from a Radio Shack when a scratchy pot on the board or a guitar got the rubbing alcohol treatment. For emergency use only on pots.
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    gto1967ho

    Posts : 1
    Join date : 2017-11-30

    Old person - old Stereo 70 - new to all this - kindergarten questions Empty Re: Old person - old Stereo 70 - new to all this - kindergarten questions

    Post by gto1967ho on Sun May 17, 2020 1:02 pm



    Last edited by gto1967ho on Sun May 17, 2020 1:21 pm; edited 2 times in total (Reason for editing : add pic)

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