How to clean contacts of a precision resistor decade (0.01%)?

[carl_lab]

Can somebody give me advice how to clean contacts of a precision resistor decade, without doing any harm to it?
I used a dry cellulose swab wiping the contact, but resistance is still unstable (rising slowly)...

I'm not quite sure, how to relubricate contacts (I'm not a believer to magic contact cleaner chemistry voodoo). There's still enough grease on the remaining contacts, so I hope it will dispense to all contacts some time later in normal usage.

Root problem still remains.
Some wiggling the dial helps temporarily, but some minutes later, resistance is increasing again.

[BU508A]

I recommend to have a look at this website:

http://thesignalpath.com/blogs/2017/02/01/deoxit-challenge-restoration-of-a-precision-decade-resistor-box/

You may find it helpful.

[VK5RC]

Cleaning  wafer switches in an old Tek scope I used IPA on foam tipped swabs (no fluff from the cotton swab) , firstly on the common contact area, then the actual moving contact till a clean swab returned, Both sides. I then used a swab lightly soaked in deoxit as a replacement lubricant - but a decade resistor box is a lot more fussy.
In wafer switches I didn't try to get between the fixed contact and the moving piece as I figured I would do more damage. (I have used heavy paper to clean between relay contacts with success.) 
If I recall correctly,  Shariar used quite a bit of deoxit - I didn't use nearly that much and applied it just to the contact areas.
Rob  VK5RC

[alm]

Caig recommends that critical, low current connections (which in my opinion includes decade resistor switches) be finished with Deoxit Gold G after cleaning with Deoxit D (or any other cleaning method that removes corrosion). If the contacts are not visibly dirty, I just spray a little G5 on them and rotate the switches a couple of times.

[carl_lab]

Deoxit is not very common in Germany, difficult to find...

[BU508A]

You can find it on Amazon:

DeoxIT D100S-2
https://www.amazon.de/dp/B0014F110I

Deoxit DeoxIT D5S-6:
https://www.amazon.de/dp/B0002BBV4G

[carl_lab]

Yes, I've seen the offer on amazon, but we cannot buy from amazon (because of our business guidelines... )

[Kjelt]

There must be some replacement from Kontakt Chemie, I would sent then an email asking what they have to offer. I know they have multiple cleaners each for their own application.

[BU508A]

Yes, I've seen the offer on amazon, but we cannot buy from anazon (because of our busyness guidelines... )

 

Probably this shop is accepted by your company's business guidelines:
http://www.micro-tools.de/Kontaktreiniger-oxid/

[BU508A]

There must be some replacement from Kontakt Chemie, I would sent then an email asking what they have to offer. I know they have multiple cleaners each for their own application.

IIRC the volt-nuts recommend Deoxit from CAIG. Not sure, if Kontakt Chemie (I know them well) achieves the same performance.

[carl_lab]

I know Kontakt-Chemie well, but I'm not longer a fan of Kontakt-Chemie since the infamous "Kontakt 60" disaster many years ago.

[Kjelt]

I know Kontakt-Chemie well, but I'm not longer a fan of Kontakt-Chemie since the infamous "Kontakt 60" desaster many years ago.

  what was that?

[mcinque]

since the infamous "Kontakt 60" desaster many years ago.

What disaster?

[carl_lab]

Kontakt-60 was very aggressive, and if not washed out carefully after application, contacts were destroyed.
Even the original metal can was destroyed by pitting corrosion (that's my personal experience, confirmed by some colleagues).
Not exactly the magic agent I want to remain in my precision instruments...
http://www.hifi-forum.de/viewthread-84-1094.html

https://www.amazon.de/CRC-Kontakt-Chemie-Kontaktspray-100ml/dp/B001CRC22Y
"Ein Nachteil:
Im Laufe von vielen Jahren (>15) wurde meine erste Dose von innen her undicht, und der Inhalt verteilte
sich immer mehr im Aufbewahrungskarton. Die Dose rostete von innen her durch. Wahrscheinlich haben die
z.T. aggressiven Inhaltsstoffe das Metall zum korrodieren gebracht."

What about "Oszillin T6" ?
http://teslanol.ch/teslanol-produkte-uebersicht.html?id=5
https://www.elv.de/teslanol-kontakt-tuner-spray-200-ml.html

[Vgkid]

What is the decade(model/manufacturer)
Post pics of the switches. That will help in the determination of the course of action.

[carl_lab]

It's a Burster 1422:



I can post photos of the switches tomorrow.

[babysitter]

Hier als Datenpunkt: Ein zufriedener Nutzer von Teslanol Oszillin. Solltest Du im RheinMainGebiet sitzen kannst Du dir einen oder Spritzer abholen ohne ganze Flasche zu kaufen!

BTW: Das Kontakt 60 kann man zum _reinigen_ verwenden, wenn man es hinterher gut auswäscht.

[Vgkid]

It's a Burster 1422:
I can post photos of the switches tomorrow.

I look forward to it. Burster makes some high quality resistors.

[BU508A]

Here you can find a .pdf of the Burster 1422:

http://www.physicomcorp.com/doc_series/1422_Ser_Ovr.pdf

Nice gear, btw. 

[carl_lab]

New photos...

[carl_lab]

.

[carl_lab]

..

[carl_lab]

...

[carl_lab]

Here you can find a .pdf of the Burster 1422:

http://www.physicomcorp.com/doc_series/1422_Ser_Ovr.pdf

Nice gear, btw. 

Thank you!

... Ein zufriedener Nutzer von Teslanol Oszillin. Solltest Du im RheinMainGebiet sitzen...

You have mail! (PM)

[Kjelt]

Kontakt-60 was very aggressive, and if not washed out carefully after application, contacts were destroyed.
Even the original metal can was destroyed by pitting corrosion (that's my personal experience, confirmed by some colleagues).
Not exactly the magic agent I want to remain in my precision instruments...

Just checked and 
Darn I bought this can I think two or three years ago, what a mess.
But indeed it needs to be washed with WL that is standard practice.
BTW: I got the same problem two years ago with a can of videohead cleaner, but that took ten years to rost through and is not corrosive at all.
Any bit of moisture inside can start the process.