Author Topic: Lube DMM Selector Switch?  (Read 13532 times)

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Offline Lightages

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Re: Lube DMM Selector Switch?
« Reply #50 on: July 04, 2017, 03:38:53 am »
Do we know if there have been any changes to the formulation of WD-40 since then?

Good question. The one thing we know for sure is that it contains flammable liquids, as per the MSD sheets. I am sure that putting flammable liquids inside a CAT rated multimeter is not conducive to safety.
 

Offline lowimpedance

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Re: Lube DMM Selector Switch?
« Reply #51 on: July 04, 2017, 04:13:36 am »
For some historical reference of what Tektronix recommended in their 475 CRO service manual

That document is 44 years old. I think we have learned a bit about material science and chemistry since then. WD40 is also 64 years old.
https://en.wikipedia.org/wiki/WD-40
Only provided for historical value, make of it what you like.
Perhaps its these types of documented uses that over time may have shaped peoples opinions/attitude to using what is a very familiar brand product ......whether that has been for the correct purpose is the real question.
 And just so you know I would not use it either in my electronics and with so many more suitable and 'improved' modern products why would you.
The odd multimeter or 2 or 3 or 4...or........can't remember !.
 

Offline Vtile

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Re: Lube DMM Selector Switch?
« Reply #52 on: July 04, 2017, 02:03:52 pm »
I would be the first to state that it's not really the correct stuff to lubricate switches.  However it's basically a light oil in a solvent, the same as most other penetrating oils, so has very similar properties, i.e. fine for very light duty lubrication, freeing of rusty/stuck parts and it's excellent at removing heavy oil and grease.
The problem is that the solvent removes any existing lubricant, and the light oil will evaporate soon. Leaving an unlubricated (is that a word?) joint. So the correct statement is that it does not lubricate for long ;).
Take a sheet of glass > clean it with IPA > place a small dot of WD40 > place in a box / "dust free" storage > wait > examine the results.

IIRC some of the metrology grade stuff Dave have reviewed did suggest to use WD40 on the rotary switches. This doesn't of course mean it is suitable for general use in every such device.
« Last Edit: July 04, 2017, 02:06:12 pm by Vtile »
 

Offline floobydust

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Re: Lube DMM Selector Switch?
« Reply #53 on: July 04, 2017, 07:31:21 pm »
You can reverse-engineer WD-40 from the WD-40 MSDS datasheet. It's basically kerosene and napthalene for solvent, and transformer/mineral oils for lube. I only use the stuff on my car for rusted bolts and find the lubricant evaporates in days and not long lasting.

Someone mentioned silicone grease (dielectric) is not good.
Has anyone tried it?

 

Online joeqsmith

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Re: Lube DMM Selector Switch?
« Reply #54 on: July 04, 2017, 09:03:29 pm »
Both that GE high voltage grease and MSD grease are silicone.  Yes, I have used it on the multi-meter rotary switches.  I use that GE stuff for a lot of high voltage applications.  I'm sure there is much better stuff out there.
How electrically robust is your meter?? https://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 

Offline eKretz

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Re: Lube DMM Selector Switch?
« Reply #55 on: July 05, 2017, 01:31:25 am »
The Nye gel lube that Fluke specs for the rotary switch is a silicone grease carrier with some fluorocarbon solids added from what I can gather by reading the MSDS. Silicone grease is fine for low voltage or non-arcing applications in my experience.
 

Online joeqsmith

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Re: Lube DMM Selector Switch?
« Reply #56 on: July 05, 2017, 02:41:46 am »
Looked like it was obsolete.  I spent a little time looking at what they offer now.  I wonder if anyone knows what Fluke is now using. 
How electrically robust is your meter?? https://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 

Offline alm

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Re: Lube DMM Selector Switch?
« Reply #57 on: July 05, 2017, 03:14:56 am »
Silicone grease is fine for low voltage or non-arcing applications in my experience.
As long as there are no contacts that might arc anywhere close either. I believe in the case of the telephone exchanges the grease was also not applied to the relay contacts, but to some other part and migrated to the contacts. Due to the property of migrating everywhere and being very hard to remove (not soluble in common solvents), it was banned in some labs for fear of contamination.
 

Offline floobydust

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Re: Lube DMM Selector Switch?
« Reply #58 on: July 05, 2017, 03:41:05 am »
From the late '90's Fluke 87 service manual, in our rehash of this thread...
"Rotary Switch
To clean the rotary switch potentiometer, do the following:
1. Remove the circuit board assembly as described earlier under “Removing and Reinserting the Circuit Board Assembly”.
2. From the back of the circuit board assembly, push the switch shaft in, and remove the polymer thick film (ptf) contact assembly.
3. Clean the ptf contact assembly and the potentiometer on the circuit assembly with alcohol. Blow these parts dry with clean, dry air.
4. Using a Q-tip, apply a thin film of W. F. Nye Gel Lubricant, #813S (Fluke PN 926084), to the entire surface of the ptf pattern and the hole in the center of the pattern. It is important that the grease be applied in a film of consistent thickness such that grease does not accumulate on the ptf wiper contacts. Remove excess grease with a dry Q-tip. No portion of the ptf pattern should be left unlubricated.
5..."

NYE Part number seems be FLUOROCARBON GEL 813S-1 MSDS

"A very soft, PTFE thickened, medium viscosity chlorophenyl silicone grease for potentiometers, electrical contacts and precision instruments exposed to extreme temperatures. Benefits include excellent thermooxidative stability, unusually low volatility."




 
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Offline Electro Detective

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Re: Lube DMM Selector Switch?
« Reply #59 on: July 06, 2017, 03:16:16 am »
Forgot to mention earlier that if WD40 isn't anyone's cup of tea as a desperate measure,

KFC finger juice applied sparingly can get the job done too in a pinch  :-+ 


unless the Colonel has changed the formula in the last few years   :-DD

 

Offline floobydust

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Re: Lube DMM Selector Switch?
« Reply #60 on: July 06, 2017, 05:54:04 am »
Forgot to mention earlier that if WD40 isn't anyone's cup of tea as a desperate measure,

KFC finger juice applied sparingly can get the job done too in a pinch  :-+ 


unless the Colonel has changed the formula in the last few years   :-DD

They have KFC in Australia, how about that.
Colonel Sander's deep-fryer used corn oil, but now it is soy/canola blend. Yes changed in the last few years  ;D

Did you know PDMS, dimethylpolysiloxane a silicone-based synthetic polymer is added to deep-fryer oil as an anti-foaming additive.

Possibly better for your multimeter than WD-40 with its nasty plastic eating solvent.
 

Offline rsjsouza

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Re: Lube DMM Selector Switch?
« Reply #61 on: July 06, 2017, 12:25:55 pm »
https://www.eevblog.com/forum/reviews/question-dmm-grease/

http://www.machinedesign.com/archive/lubricating-electrical-switches

Honest, I did search, but ran out of oomph. Deja Vu.

Some folks would apply a few second spray of WD40 so enough got under the PCB to make it to the contacts, then work it around a bit, then give it a rinsing spritz. The good old days...  8)

No problem. I've never been impressed with this site's search engine.  Hopefully you found something useful.
I usually go to an internet search engine and type "<search term> site:eevblog.com " without the quotes. It works really well for me.
« Last Edit: July 06, 2017, 03:57:31 pm by rsjsouza »
Vbe - vídeo blog eletrônico http://videos.vbeletronico.com

Oh, the "whys" of the datasheets... The information is there not to be an axiomatic truth, but instead each speck of data must be slowly inhaled while carefully performing a deep search inside oneself to find the true metaphysical sense...
 

Offline metrologist

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Re: Lube DMM Selector Switch?
« Reply #62 on: July 06, 2017, 03:55:14 pm »
I tried that again today and got better results... Most topics I read previously introduced lubrication as an ancillary topic and it was taking a while. Now that I have better terms I found Rob Renz's replies and links amongst others. Now I will panic over using a silicone based grease.
 

Offline eKretz

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Re: Lube DMM Selector Switch?
« Reply #63 on: July 06, 2017, 11:23:56 pm »
The NYE lube recommended for the rotary switch by Fluke IS a silicone based grease:

Quote
NYE Part number FLUOROCARBON GEL 813S-1 MSDS

"A very soft, PTFE thickened, medium viscosity chlorophenyl silicone grease for potentiometers, electrical contacts and precision instruments exposed to extreme temperatures. Benefits include excellent thermooxidative stability, unusually low volatility."

I would refrain from using silicone based grease in an application that even has any arcing components NEARBY the application site, but personally I will still use it anywhere that has a continuous contact or on very low voltage/current switches that are very unlikely to experience any arcing. I've followed the same guidelines for nearly a couple decades now with no issues. The appropriate Caig/DeOxit products work well for the others.
 

Offline Electro Detective

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Re: Lube DMM Selector Switch?
« Reply #64 on: July 07, 2017, 02:10:29 am »
Has anyone tried applying Windex very sparingly in a desperate 'need the meter working NOW'  |O  dry selector track scenario yet? 
 

Online BradC

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Re: Lube DMM Selector Switch?
« Reply #65 on: July 07, 2017, 02:57:11 am »
Has anyone tried applying Windex very sparingly in a desperate 'need the meter working NOW'  |O  dry selector track scenario yet?

Windex contains Ammonia. Ammonia and copper don't play well together.
 
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Offline Electro Detective

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Re: Lube DMM Selector Switch?
« Reply #66 on: July 07, 2017, 03:01:32 am »
would it give the copper tarnish a good scrub ?
 

Offline Lightages

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Re: Lube DMM Selector Switch?
« Reply #67 on: July 07, 2017, 03:41:43 am »
would it give the copper tarnish a good scrub ?

So you don't wanna be seen as a troll, but keeping polluting the thread with nonsense.  ::)
 

Offline floobydust

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Re: Lube DMM Selector Switch?
« Reply #68 on: July 07, 2017, 05:04:27 am »
I think the anti-silicone lube post is copy pasta of Electrolube's marketing sheet. They don't mention what alternative is used in their products.

I call bull on it as high-voltage switchgear manufacturers are using silicone grease. And we aren't arcing and making silicon-carbide here in our DMM's.
And (old) Fluke advises NYE silicone-lube (with teflon). So I'm in the pro-silicone camp.

I think the chemical compatibility is important- with copper, gold, plastic, rubber, phenolic and FR-4 pcb etc. inb DMM's.
Silicones are quite inert, so I think they are a good choice.
 

Offline Electro Detective

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Re: Lube DMM Selector Switch?
« Reply #69 on: July 07, 2017, 08:00:15 am »
would it give the copper tarnish a good scrub ?

So you don't wanna be seen as a troll, but keeping polluting the thread with nonsense.  ::)

That's your say so, and not my problem if discussion re easily available and cheap generic cleaning and lube chemicals don't interest you 



I think the anti-silicone lube post is copy pasta of Electrolube's marketing sheet. They don't mention what alternative is used in their products.

I call bull on it as high-voltage switchgear manufacturers are using silicone grease. And we aren't arcing and making silicon-carbide here in our DMM's.
And (old) Fluke advises NYE silicone-lube (with teflon). So I'm in the pro-silicone camp.

I think the chemical compatibility is important- with copper, gold, plastic, rubber, phenolic and FR-4 pcb etc. inb DMM's.
Silicones are quite inert, so I think they are a good choice.

HV switchgear lubricants is a hard one, especially inside a sealed unit exposed to high and low temperatures, and the time factor.

I've seen the insides of failed switches where the lube had turned to hard green slime, sometimes making contact only on hot days.

Silicones are ok if they don't slime about into places they shouldn't, or get chunky and cause issues

 

« Last Edit: July 07, 2017, 08:31:07 am by Electro Detective »
 

Online BradC

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Re: Lube DMM Selector Switch?
« Reply #70 on: July 07, 2017, 09:31:32 am »

That's your say so, and not my problem if discussion re easily available and cheap generic cleaning and lube chemicals don't interest you 

The problem is you keep posting ill considered opinions with no consideration towards material compatibility. I originally had you pegged as a troll, but now I'm pretty convinced you just don't know any better.

 

Offline stj

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Re: Lube DMM Selector Switch?
« Reply #71 on: July 07, 2017, 09:52:05 am »
you need to make sure the chemicals dont effect plastics or rubber - it's not just the dielectric property's
 

Offline Electro Detective

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Re: Lube DMM Selector Switch?
« Reply #72 on: July 07, 2017, 11:39:44 pm »
you need to make sure the chemicals dont effect plastics or rubber - it's not just the dielectric property's

Agreed  :-+    I test chemicals on landfill bound unserviceable electronics and boards first, before applying or spraying into a working device,
and give lubed traces a good zap with 50v to 1000v insulation tester/Megohm meter (been doing that before there was an 'internet') to see how well or how bad a product performs, and repetitive mechanical/friction tests 

I don't just buy into any hyped product, or a handful of user recommendations (who may be silently sponsored)   ::)

For example, take De0xit, there are other MUCH CHEAPER products that do the same job if not better  :clap:

I bought and tried ALL the magic sprays and greases years ago, and ran them to see what worked, and what didn't work as well

The exercise and initial cash outlay saves money and service grief in the long term,
NO COMEBACKS,
and you eventually use up the stuff anyway where it suits, so no money wasted 


Please wait a minute for the 'troll' call on this comment too   ;D

« Last Edit: July 07, 2017, 11:53:14 pm by Electro Detective »
 

Offline Lightages

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Re: Lube DMM Selector Switch?
« Reply #73 on: July 08, 2017, 03:52:21 am »
I don't just buy into any hyped product, or a handful of user recommendations (who may be silently sponsored)   ::)

OK, so who are you accusing of being a lying company shill?
 

Offline Electro Detective

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Re: Lube DMM Selector Switch?
« Reply #74 on: July 08, 2017, 09:48:29 am »
what's it worth to you?   8)
« Last Edit: July 08, 2017, 09:53:07 am by Electro Detective »
 


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