Greasing up switches and connectors?

[DaveC]

Cleaning up an old rotary mode switch used for 5v logic levels. It has some
kind of grease in it.


…which has always confused me: grease is an insulator (well, the grease in
this switch is—just tested and it’s infinite ohms).

I read that dielectric grease is good to keep contacts sealed against the
elements that have high physical pressure (which overcomes any separation
provided by the grease) but that signal and other low voltages grease is
contra-indicated.

What say y’all?

Thanks.

 

On Saturday, March 5, 2016 at 9:14:19 AM UTC-8, DaveC wrote:

Cleaning up an old rotary mode switch used for 5v logic levels. It has some
kind of grease in it.


...which has always confused me: grease is an insulator (well, the grease in
this switch is--just tested and it's infinite ohms).

I read that dielectric grease is good to keep contacts sealed against the
elements that have high physical pressure (which overcomes any separation
provided by the grease) but that signal and other low voltages grease is
contra-indicated.

What say y'all?

Thanks.

I use GC 10-8101 grease on outdoor F connectors under the weather boot to keep the oxidation down. I opened a 15 year old connection and it looked like new inside. The antenna was trash but the cable was excellent.

http://www.gcelectronics.com/order/DataSheets/10-8101,%2010-8102,%2010-568%20Silicone%20Compound.pdf

G˛

 

[Jeff Liebermann]

On Sat, 5 Mar 2016 15:52:22 -0800 (PST), stratus46@yahoo.com wrote:

On Saturday, March 5, 2016 at 9:14:19 AM UTC-8, DaveC wrote:
Cleaning up an old rotary mode switch used for 5v logic levels. It has some
kind of grease in it.


...which has always confused me: grease is an insulator (well, the grease in
this switch is--just tested and it's infinite ohms).

I read that dielectric grease is good to keep contacts sealed against the
elements that have high physical pressure (which overcomes any separation
provided by the grease) but that signal and other low voltages grease is
contra-indicated.

What say y'all?

Thanks.

I use GC 10-8101 grease on outdoor F connectors under the weather boot to keep the oxidation down. I opened a 15 year old connection and it looked like new inside. The antenna was trash but the cable was excellent.
http://www.gcelectronics.com/order/DataSheets/10-8101,%2010-8102,%2010-568%20Silicone%20Compound.pdf
G˛

GC 10-8101 is a "dielectric grease". From the above URL:
"... to prevent electrical power from migrating between circuitry".
Dielectric means "insulator" in this case, which is not exactly what I
would want in an RF connector.
<https://en.wikipedia.org/wiki/Silicone_grease#Dielectric_grease>

Perhaps some conductive grease would make a better connection?
<http://www.sanchem.com/electrical-contact-lubricant.html>

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[DaveC]

Jeff Liebermann wrote:

Dielectric means "insulator" in this case, which is not exactly what I
would want in an RF connector.

Jeff, I think he means he uses it under the boot, not inside the connector…

Dave

 

[Jeff Liebermann]

On Sat, 05 Mar 2016 20:27:52 -0800, Jeff Liebermann <jeffl@cruzio.com>
wrote:

Perhaps some conductive grease would make a better connection?
http://www.sanchem.com/electrical-contact-lubricant.html

I forgot the data sheet:
<http://www.sanchem.com/docs/NO-OX-ID%20A-Special%20WW.pdf?r=false>
eBay link:
<http://www.ebay.com/sch/i.html?_nkw=no-ox-id>
and MSDS:
<http://www.northtowncompany.com/pdfs/no-ox-id%20a%20special%20msds.pdf>

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[DaveC]

I use GC 10-8101 grease on outdoor F connectors under the weather boot to
keep the oxidation down. I opened a 15 year old connection and it looked like
new inside. The antenna was trash but the cable was excellent.

You put it inside the boot but not inside the connector (not inside the
F-conn), right?

Thanks.

 

[Bruce Esquibel]

DaveC <not@home.cow> wrote:

You put it inside the boot but not inside the connector (not inside the
F-conn), right?

Actually when home satellite systems (c/ku band) were common, filling up the
F connector and the boot was a common practice when attaching the cables to
the lnb's.

The general logic was, there was a zero chance of water getting in anywhere
and also removed the chance of oxidation.

I don't remember what they used but I remember that guy Shaun Kenny selling
it on that Boresight show for that specific reason.

-bruce
bje@ripco.com

 

[N_Cook]

On 05/03/2016 17:14, DaveC wrote:

Cleaning up an old rotary mode switch used for 5v logic levels. It has some
kind of grease in it.


…which has always confused me: grease is an insulator (well, the grease in
this switch is—just tested and it’s infinite ohms).

I read that dielectric grease is good to keep contacts sealed against the
elements that have high physical pressure (which overcomes any separation
provided by the grease) but that signal and other low voltages grease is
contra-indicated.

What say y’all?

Thanks.

Over the years all those problematic radio multiway wavechange and tape
recorder play/record slide switches. I never saw grease inside them and
the failure was due to black corrossion product copper suplphide? which
is an insulator that a phosphor bronze contact could not wipe/break
through to make contact. The worst black was at the more open ends to
the air, rather than the core of the switch body.

 

On Saturday, March 5, 2016 at 9:11:03 PM UTC-8, DaveC wrote:

Jeff Liebermann wrote:

Dielectric means "insulator" in this case, which is not exactly what I
would want in an RF connector.

Jeff, I think he means he uses it under the boot, not inside the connector...

Dave

I actually put it directly on the center conductor after the connector is attached and then screw it on the fitting. While the grease is an 'insulator', the metal parts touch and the grease prevents moisture getting to the wire. I did not put any grease on the rubber boot except for any residue that was on the outside of the connector.

G˛

 

[Kevin McMurtrie]

In article
<0001HW.1C8B4B670002EE5111CD2E3CF@news.eternal-september.org>,
DaveC <not@home.cow> wrote:

Cleaning up an old rotary mode switch used for 5v logic levels. It has some
kind of grease in it.


…which has always confused me: grease is an insulator (well, the grease in
this switch is—just tested and it’s infinite ohms).

I read that dielectric grease is good to keep contacts sealed against the
elements that have high physical pressure (which overcomes any separation
provided by the grease) but that signal and other low voltages grease is
contra-indicated.

What say y’all?

Thanks.

Grease is more easily pinched through than corrosion. It extends the
life of sliding switches by reducing friction.

It's only used for low level signal switching. Grease and oil slow down
switching time so they'll cause power switches to arc and catch fire.

--
I will not see posts from astraweb, theremailer, dizum, or google
because they host Usenet flooders.

 

[Jeff Liebermann]

On Sat, 05 Mar 2016 21:10:59 -0800, DaveC <not@home.cow> wrote:

Jeff Liebermann wrote:

Dielectric means "insulator" in this case, which is not exactly what I
would want in an RF connector.

Jeff, I think he means he uses it under the boot, not inside the connector…
Dave

Yep. "...under the weather boot to keep the oxidation down". My
apologies for expanding the topic, but I assumed that connector
performance was more important than surface cosmetics.

The problem with petroleum based greases, such as GC 10-8101 which is
about 10-15% mineral oil, is they cause the rubber boot and F
connector O-ring seal, to swell and possibly deteriorate depending on
rubber composition. I must admit that I've never seen it happen where
it can be easily attributed to grease because nobody around here
covers the outsides of TV/CATV/TVRO/DBS connectors with grease. For
more expensive RF connectors, where water incursion is a problem, I
wrap the connectors with PTFE tape followed by a layer of electrical
tape. Then some clear acrylic spray to reduce UV deterioration.

Another problem is that greases like to migrate when warm. I can
usually tell when someone has stuffed a connector full of grease
because the grease eventually appears on the outside of the connector
where it accumulates dirt and dust. Capillary action also works for
viscous fluids, like grease. I've been told that F connector threads
are designed to be a rather loose fit to handle expansion caused by
corrosive products (aluminum oxide) and not jam the threads. If true,
such threads would not make a very good seal.

The phone monopolies have the same problem with outdoor NID (network
interface device) boxes, which have at least one RJ11 connector. The
gold connector wires can take care of themselves, but the copper flat
ribbon cable that connect to the RJ11 are a problem. Instead of
grease, they use a very viscous polydimethylsiloxane (silicone) gel to
seal the connector area. There's a tech description near the bottom
of the patent:
<http://www.google.com/patents/US6971897>
A gel doesn't run when hot and doesn't seem to attract dirt because
it's fairly non-sticky. Note that all the references at the bottom
are for a "gel" compound, not a "grease".




--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[Ian Field]

"DaveC" <not@home.cow> wrote in message
news:0001HW.1C8B4B670002EE5111CD2E3CF@news.eternal-september.org...

Cleaning up an old rotary mode switch used for 5v logic levels. It has
some
kind of grease in it.


…which has always confused me: grease is an insulator (well, the grease in
this switch is—just tested and it’s infinite ohms).

When I worked for a calibration firm, they had special contacts grease for
the old decade boxes. AFAICR: it was called Elvolube - but I haven't been
able to find it online.

Often I use GT85 - its like WD40 but PTFE enhanced, it doesn't interfere
with contacts but the solvent destroys any ABS plastics in anything you
spray it on.

 

[N_Cook]

On 05/03/2016 17:14, DaveC wrote:

Cleaning up an old rotary mode switch used for 5v logic levels. It has some
kind of grease in it.


…which has always confused me: grease is an insulator (well, the grease in
this switch is—just tested and it’s infinite ohms).

I read that dielectric grease is good to keep contacts sealed against the
elements that have high physical pressure (which overcomes any separation
provided by the grease) but that signal and other low voltages grease is
contra-indicated.

What say y’all?

Thanks.

Can we summarise this thread by saying -
Any grease is better than no grease, in low voltage, wiped contact
situations, as long as the grease doesn't go hard with age or otherwise
degrade or corrode the contacts itself

 

[John-Del]

Interesting. I was always under the impression that *any* lubricant, whether a fine liquid to a grease would be pushed aside by a sliding electrical contact and electrical contact would be made on the molecular level. The lubricant would surround the contact points and deny air and moisture access to the contact.

I've used dielectric grease on vintage automobile harnesses and bulb sockets and have never had a problem with contacts afterwards.

 

[Ian Field]

"N_Cook" <diverse@tcp.co.uk> wrote in message
news:nbjbp3$uo0$1@dont-email.me...

On 05/03/2016 17:14, DaveC wrote:
Cleaning up an old rotary mode switch used for 5v logic levels. It has
some
kind of grease in it.


…which has always confused me: grease is an insulator (well, the grease
in
this switch is—just tested and it’s infinite ohms).

I read that dielectric grease is good to keep contacts sealed against the
elements that have high physical pressure (which overcomes any separation
provided by the grease) but that signal and other low voltages grease is
contra-indicated.

What say y’all?

Thanks.


Can we summarise this thread by saying -
Any grease is better than no grease,

Some mechanical engineering greases contain a significant proportion of
water.

Not certain - but that may open the possibility of corrosive decomposition
products.

Many greases are lithium based, its probably bound up in stable compounds,
but very reactive if it gets loose.

Molybdenum grease is probably OK except in high voltage or high impedance
work - graphite grease is probably not OK for anything electrical. Graphite
is the lubricant of choice for brass, such as locks etc.

PTFE penetrating oil works well on contacts, as for grease the one I know of
is Finish-line PTFE fortified bicycle grease. It works OK on heavy contacts,
but may isolate the wiper on light duty switchgear.

Silicone grease is exactly opposite to hygroscopic - it repels water.

 

[Jeff Liebermann]

On Sun, 6 Mar 2016 13:05:41 -0800 (PST), stratus46@yahoo.com wrote:

On Saturday, March 5, 2016 at 9:11:03 PM UTC-8, DaveC wrote:
Jeff Liebermann wrote:

Dielectric means "insulator" in this case, which is not exactly what I
would want in an RF connector.

Jeff, I think he means he uses it under the boot, not inside the connector...

Dave

I actually put it directly on the center conductor after the connector is attached and then screw it on the fitting. While the grease is an 'insulator', the metal parts touch and the grease prevents moisture getting to the wire. I did not put any grease on the rubber boot except for any residue that was on the outside of the connector.

G˛

<http://www.wisegeek.org/what-is-dielectric-grease.htm>
"Besides being used to seal rubber covers on electrical
connections, dielectric grease also prevents corrosion
when applied directly to metal connectors. Though it
works well for this purpose, it can sometimes cause a
connection to stop working if not all of the grease is
pushed out of the way between the points of contact
inside the connector."

Wiping off silicone grease from a connector pin is difficult, messy,
and requires solvents. If you read other articles on the electrical
uses for dielectric grease, you'll find that they all discuss how it
is applied to everything EXCEPT the conductors. For example:

<http://www.rx7club.com/2nd-generation-specific-1986-1992-17/fyi-about-dielectric-grease-electrical-components-979955/#post10895971>
"one thing people have tried is dielectric grease on various
electrical component connections. this is NOT a good idea!
dielectric grease or "tune up grease" as you may find in auto
parts stores is ONLY meant for high voltage connections such
as spark plug wires, that is about the only place it belongs
on a car.

using it on electrical connections, eventually you may as well
pitch the harness into the garbage.. it's almost impossible to
get the stuff out once it's in there, dielectric grease does
not conduct electricity very well and will in fact cause
resistance issues and eventually failed connections."

etc...

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[Ian Field]

"John-Del" <ohger1s@aol.com> wrote in message
news:deb53566-c135-443e-8b84-04e7c620b327@googlegroups.com...

Interesting. I was always under the impression that *any* lubricant,
whether a fine liquid to a grease would be pushed aside by a sliding
electrical contact and electrical contact would be made on the molecular
level.

Some technical journal informed me that this planet has a smoother surface
than any ball bearing that can be manufactured - apparently; that includes
the fact that centrifugal force gives the planet a greater diameter at the
equator than at the poles.

If you looked at an electron-micrograph of the contact surfaces - you'd
think you were looking at a mountain range.

 

[Jeff Liebermann]

On Mon, 7 Mar 2016 13:10:22 -0800 (PST), John-Del <ohger1s@aol.com>
wrote:

Interesting. I was always under the impression that *any* lubricant,
whether a fine liquid to a grease would be pushed aside by a
sliding electrical contact and electrical contact would be made
on the molecular level. The lubricant would surround the contact
points and deny air and moisture access to the contact.

Or trap moisture if it was wet when you inserted the connector. Based
on my limited automotive and marine radio experience, I think grease
is a bad idea. However, there are places where it will do as you
suggest. If there's AC or DC current going through the connection,
and the connection is under some pressure, you can get a reasonable
connection. Dry loads such as TV/cable/RF don't work well or for very
long. If the connection moves, and is designed for self cleaning
operation, such as in a switch or relay, it will work for a while.

The problem is not only from the insulating properties of the
dielectric grease, but also from the dirt and grit that are attracted
by the grease. As the dirty grease builds up, it becomes thicker and
thicker. Eventually, the grease hardens sufficiently to force the
contacts to ride up onto the layer of dirty grease, instead of making
a connection. This is a very common problem with potentiometers that
are lubricated with greases diluted by solvents. When the solvents
evaporate, the remaining grease is almost thick enough to cause the
wiper to ride up onto the grease. Few people do this, but as I
mentioned, the grease gets thick enough from being mixed with carbon
particles scraped off from the resistance element to cause a problem.

If you need to be convinced more, please buy some phosphorescent
powder on eBay.
<http://www.ebay.com/sch/i.html?_nkw=phosphorescent+powder>
<http://www.allureglow.com.au/powder.php>
<http://www.crimescene.com/store/index.php?main_page=product_info&products_id=76>
Try to get the finest grain powder possible. Most of my pile is 10
and 15um. I haven't tried the criminal investigation stuff, but I'm
fairly sure it will work.

Also get a UV (365nm) flashlight. Mix a little with your grease of
choice and apply to a flat piece of steel, aluminum, or copper (so you
can see what you're doing). Rub it in and then wipe the grease off
without solvents. Use the UV light to see how much is left. There
should be plenty. Now, try some common solvents. More will
disappear, but you'll still have plenty of grease left on the surface.
If you have a microscope handy, you can see a microscopic thin layer
of glowing grease.

I've used dielectric grease on vintage automobile harnesses and bulb
sockets and have never had a problem with contacts afterwards.

I bought an Isuzu Trooper cheap from someone that took it to Burning
Man. When it came back, many of the electrical connections were
intermittent. The cause was dielectric grease in the connectors,
mixed with fine desert sand and dust. After some experimentation, I
used a small ultrasonic clean and trichlorethylene to dissolve the
grease. I initially made the intermittents worse, but after two more
applications, the contacts were finally deemed clean.

Diversion: Of all the connectors available, the common F-connector is
the only one that is made from enough dissimilar metals to insure
galvanic corruption. The connector shell is made from aluminum or
brass. It is plated with alodine 1200, nickel, chrome, gold, pyrite,
or nothing. The coax center wire is copper plated steel or solid
copper. The foil and braid shields are aluminum. With this mix of
dissimilar metals, if you get any water inside, something is going to
corrode.


--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[Jeff Liebermann]

On Mon, 07 Mar 2016 17:50:17 -0800, Jeff Liebermann <jeffl@cruzio.com>
wrote:

Diversion: Of all the connectors available, the common F-connector is
the only one that is made from enough dissimilar metals to insure
galvanic corruption. The connector shell is made from aluminum or
brass. It is plated with alodine 1200, nickel, chrome, gold, pyrite,
or nothing. The coax center wire is copper plated steel or solid
copper. The foil and braid shields are aluminum. With this mix of
dissimilar metals, if you get any water inside, something is going to
corrode.

I forgot to mention the center connection, which is made from tin
plated brass.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[DaveC]

Grease is more easily pinched through than corrosion. It extends the
life of sliding switches by reducing friction.
Kevin Mc

And by extension, oil is better at preventing corrosion while not sticking up
things.

This research found that simple mineral oil reduced contact resistance
dramatically:

http://www.te.com/documentation/whitepapers/pdf/p154-74.pdf

I (op) decided I’m going to cleans out this mode switch and try Caig
DeOxit.

Thanks for all the great discussion.