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Dedicated to the restoration and preservation of all original Dynaco tube audio equipment - Customer support for Tubes4hifi VTA tube amp and preamp kits and all products

    Contact cleaner


    Posts : 216
    Join date : 2012-03-19

    Contact cleaner Empty Contact cleaner

    Post by wildiowa on Mon Mar 11, 2019 10:52 am

    Any consensus on the best contact cleaner? Time to order. I have used DeoxIt liquid with brush applicator and DeoxIt D5 spray. Local big-box store has huge can of CRC "electrical cleaner" for way cheaper. Do you get what you pay for, or is it all essentially similar?
    Peter W.
    Peter W.

    Posts : 1397
    Join date : 2016-08-07
    Location : Melrose Park, PA

    Contact cleaner Empty Re: Contact cleaner

    Post by Peter W. on Mon Mar 11, 2019 12:33 pm

    It comes down to Horses for Courses.


    When, a few years ago, I had occasion to purchase the "original"
    Cramolin product in Saudi Arabia, the paper-sticker applied label
    stated: 5% Oleic Acid, 95% Petroleum distillates & Propellants.
    Propellants may be CO2 and/or Propane. Highly Flammable

    Or words to this effect - the precise wording escapes me now and the
    can I brought back is long-gone.

    Saudi has very strict labeling requirements. I could not find DeOxit
    (Caig) products in Saudi, I did look and ask.

    Draw your own conclusions.  Oleic Acid (food grade) in its pure form is available OTC, and has no postal or other regulations on sales and/or shipping.

    That being written:

    I recently had the need to clean up a quite-vintage SCA35 that had lived a very hard life. Its controls were all frozen (and the switches), it had been "Lubed" with white lithium grease, which had hardened into lithium concrete. The process was:

    - Saturate the entirety with WD-40 twice (12 hours apart).
    - Rinse with the CRC (100% volatile) you reference into a garbage back with kitty-litter to catch the non-volatiles.
    - Lubricate with Aero-Kroil - a little goes a very long way - to provide permanent lubrication to the controls and switches.
    - tighten all the tube sockets.  
    - Electrical/electronic stuff not germane.

    The World's Best Contact Cleaner is this device, or one of its more refined children:   I keep one from my long-ago college days, together with a life-time supply of inserts. The soft inserts will clean light oxides and not damage the substrate in any way. The most abrasive will take green crust from brass, yet not touch the brass (copper or steel) other than polishing it. The difficulty is using it in tight places.

    Chemical deoxidizers: These, such as the De-Oxit family, oleic acid, and others, must be 100% rinsed off after use. The reactants will continue to react until consumed, the residue(s) is (are) conductive, and could be a disaster if deposited on a switch or circuit board.  And, some (ask me how I know) will peel the trace right off a circuit board if given the time.

    Any cleaning chemical must be removed or rinsed off in any case as it will carry a freight of dirt, grease or oils.

    There are purpose-designed lubricants (such as "Fader Lube" and the like) that are designed to lubricate controls and switches after cleaning. Yes, lubrication after cleaning is necessary. What you use is your choice. I find that any number of materials compatible with the substrate, and where their residues do not harden or oxidize into varnish will work nicely. And, should you have silicon-impregnated, usually sealed, controls - DO NOT use conventional lubricants as some will destroy the silicon grease - that is where the Fader Lube specific to such controls comes into play. But the rule-of-thumb is that controls should be lubricated, and absolutely, after cleaning.   I keep some of these. I mix my own Oleic Acid cleaner using Coleman Fuel (already includes stabilizers) and mix to about 4% by volume. Also useful for bulk-purchased WD-40, pure alcohol and such.   for tightening tube sockets, testing connections, delivering a tiny amount of cleaner or lubricant and such.    NON-metallic. good for cleaning individual post sockets and other tight places.   Tip-cutting pliers.

    These are my go-to tools for cleaning and de-skunging new-to-me-items. In extreme cases, and if the alternative is landfill - I use the dishwasher (Bosch). Works like a charm - with some cautions.


    Posts : 47
    Join date : 2009-01-09
    Age : 57
    Location : Central VA

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    Post by StevieRay on Mon Mar 11, 2019 3:26 pm

    Now I am curious about the dishwasher:

    1. What settings?
    2.  What type of soap?
    3.  Just what can you and cannot you put in there?  Circuit boards?  Chassis?
    4.  If circuit boards, what will absolutely need to be replaced?  Probably not resistors, film caps, or semiconductors, but what about electrolytics, etc.?

    I've brought stuff in my house so filthy that it probably should have gone though a "Andromeda Strain" decontamination.  Scrubbed with toothbrushes and all manner of crap -- to nasty and too long.

    Are you saying the dishwasher is what to use here, or only as a last resort?

    I wish they still made Freon TF -- you could get a whole can and hose down anything without fear of it melting plastic -- washed away all dirt and grunge, and de-greased too!
    Peter W.
    Peter W.

    Posts : 1397
    Join date : 2016-08-07
    Location : Melrose Park, PA

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    Post by Peter W. on Mon Mar 11, 2019 3:53 pm

    OK - here is what has gone through our dishwasher:

    Zenith TransOceanic H500, B600, 7G605 - all with speakers, tubes and cardboard capacitor covers removed.

    Soundcraftsman T100 tuner, top off.

    Dynaco FM3, ST120, FM-5, PAT-4

    Any number of AA5 radios as above - no speaker(s), no cardboard. No Catalin. No painted dials. Effectively, no plastic cases of any nature.


    1. Wax Coated coils - these will survive the heat - they live next to tubes, remember. But, they do not like excessive amounts of detergents.
    2. IF cans - the chassis should always be on the top rack and upside down, or on a side - or whatever is best for draining. If the IF cans are reached from both top and bottom, a dab of Electronics compatible (no acetic acid) RTV silicon on the upper opening will not go amiss.
    3. Drying Cycle: The Bosch does not have an exposed heating element, and dries by blowing heated air through the compartment. DO NOT use a DW with an exposed heating element unless an absolutely last resort.
    4. Post Wash: I tend to let the item 'pickle' in the hot sun if available for at least a day. Or in an oven at 150F for a minimum of four (4) hours.
    5. Absolutely lubricate any moving parts prior to applying power afterward.
    6. "Delicate" or "China" setting - 1/2 the amount detergent. Do not shorten the cycle from whatever that setting does.
    7.. Haven't lost a patient yet.

    Yes, if the alternative is landfill, or if the item is simply not worth heroic efforts (almost the same condition).

    The inside of the Bosch gets to 150F, and sustains that (no water flow) for about 20 minutes as part of the dry cycle. Use basic judgment concerning the survivability of that component. But in a tube device, 150F isn't much.

    My wife is entirely OK with this, by the way. All she cares about is that the dishwasher is clean and odor-free when she needs it.


    Posts : 190
    Join date : 2011-04-04

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    Post by Tom on Tue Mar 19, 2019 8:13 am

    ^^^Please post pictures of wife.^^^


    (lucky devil)

    Peter W.
    Peter W.

    Posts : 1397
    Join date : 2016-08-07
    Location : Melrose Park, PA

    Contact cleaner Empty Re: Contact cleaner

    Post by Peter W. on Tue Mar 19, 2019 9:52 am

    Tom wrote:^^^Please post pictures of wife.^^^


    (lucky devil)


    I am.

    Tall, slender, blue-eyed blonde born in Norfolk, VA.

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