What is that whiteish stuff on bad batteries (ruins stuff)?

On Tue, 18 Aug 2015 12:01:51 -0700 (PDT), whit3rd <whit3rd@gmail.com>
wrote:

On Tuesday, August 18, 2015 at 8:20:56 AM UTC-7, Jeff Liebermann wrote:
On Mon, 17 Aug 2015 15:56:53 -0700 (PDT), avagadro7@gmail.com wrote:

Battery and ground contact areas eg terminals, clamps, frame connection areas are coated with a thin film of [silicone grease]

suggested that he grease his sheet metal pieces before spot welding
... the grease exploded in the spot welder
and produced a rather wide black horizontal scorch line across his
clean white shirt.

Yes, grease is good, but not in the current flow.

There's formulations of grease that don't do that, of course; silicone takes high
temperature, and some greases are intended for electrical conduction in thin
films (they 'break down' at millivolts, and don't even get hot).
http://store.caig.com/s.nl/sc.2/category.185/.f
I've used this grease on rotating connections, at 40A it's just like
a solid wire connection.
Click to expand...

Looks like aluminum dust, copper dust, graphite, and/or quartz(???).
No clue if it's graphite spheres or flakes. Ignoring quartz, the
others are not particularly great conductors because of the lack of
sufficient contact area between particles. It's much like the
conductive PCB paint used to "print" conductive traces. Even using
silver, it's not very conductive. Graphite flakes are tolerable
because the flakes overlap, but still produces high resistance
connections.

One your rotating joint connection, did you use brushes or a
commutator to make the connection? If so, the path of least
resistance is through these connections, not through the grease.
Grease will certainly help, but it works by burying any small arcing
under a layer of grease, which blocks oxygen to the arc, and therefore
reduces pitting and burning.

--
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
 
On Tue, 18 Aug 2015 16:58:50 -0700 (PDT), whit3rd <whit3rd@gmail.com>
wrote:

On Tuesday, August 18, 2015 at 4:35:13 PM UTC-7, Jeff Liebermann wrote:
On Tue, 18 Aug 2015 12:01:51 -0700 (PDT), whit3rd <whit3rd@gmail.com
wrote:

On Tuesday, August 18, 2015 at 8:20:56 AM UTC-7, Jeff Liebermann wrote:
On Mon, 17 Aug 2015 15:56:53 -0700 (PDT), avagadro7@gmail.com wrote:

Battery and ground contact areas eg terminals, clamps, frame connection areas are coated with a thin film of [silicone grease]

suggested that he grease his sheet metal pieces before spot welding
... the grease exploded in the spot welder

Yes, grease is good, but not in the current flow.

There's formulations of grease that don't do that, of course; silicone takes high
temperature, and some greases are intended for electrical conduction in thin
films (they 'break down' at millivolts, and don't even get hot).
http://store.caig.com/s.nl/sc.2/category.185/.f
I've used this grease on rotating connections, at 40A it's just like
a solid wire connection.

Looks like aluminum dust, copper dust, graphite, and/or quartz(???).

Can't be, it's transparent. It's based on a semiconductive component, which is nonlinear:
insulating in bulk, but breaks down (in conductivity, not chemical nature) in
thin films under electrical stress. US Patent #4696832 has more info.
Click to expand...

Never heard of that stuff, but if it's as you describe, it should be
quite useful. How conductive, I don't know. The patent isn't very
helpful:
<http://www.google.com/patents/US4696832>
"The contact stabilization material comprises at least one
block polymer or co-polymer of polyoxypropylene together
with polyoxyethylene."
It then points to a French patent:
<http://www.google.com/patents/EP0144399A1?cl=en>
which has a better explanation. I'll RTFM over the weeken.

I got the Caig L260 and M260 info you linked came from:
<http://store.caig.com/s.nl/sc.18/category.1049/.f>
(Sorry I forgot to include the link. Kinda crazy today). Notice the
mention of metallic filler. Is Caig L260 and M260 the right grease or
should I be looking for something else?

One your rotating joint connection, did you use brushes or a
commutator to make the connection? If so, the path of least
resistance is through these connections, not through the grease.

It was bronze rubbing on a steel element; the grease keeps the steel from oxidizing
while increasing the effective contact area.
Click to expand...

--
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
 
On Tuesday, August 18, 2015 at 7:02:20 PM UTC-7, Jeff Liebermann wrote:
On Tue, 18 Aug 2015 16:58:50 -0700 (PDT), whit3rd <whit3rd@gmail.com
wrote:

... some greases are intended for electrical conduction in thin
films (they 'break down' at millivolts, and don't even get hot).
http://store.caig.com/s.nl/sc.2/category.185/.f
I've used this grease on rotating connections, at 40A it's just like
a solid wire connection.

Looks like aluminum dust, copper dust, graphite, and/or quartz(???).

Can't be, it's transparent. It's based on a semiconductive component, which is nonlinear:
insulating in bulk, but breaks down (in conductivity, not chemical nature) in
thin films under electrical stress. US Patent #4696832 has more info.

Never heard of that stuff, but if it's as you describe, it should be
quite useful. How conductive, I don't know. The patent isn't very
helpful:
http://www.google.com/patents/US4696832
Click to expand...

Yeah, there's a high information cost... and there's more boosterism than
chemical physics in the sales lit. As to 'how conductive', the L260 variant
that I used doesn't have conductive particles, so it only conducts in thin films,
like rubbing parts would have around contact points. Because it is nonlinear,
'conductivity' is undefined (and the rubbing of bumpy surfaces mean
the film thickness is likewise indefinite). Variants on this lubricant
are recommended for slide potentiometers, I see.

The admixture of conductive particles would make a grease conduct electricity,
but that would be unsafe in electrical panels (and the intended uses include busbars).
It would decalibrate potentiometers, too. Because metallic particles would
constitute dissimilar metals in my mechanism, I didn't want to use such a grease.
 
On Wednesday, August 19, 2015 at 4:20:17 AM UTC-4, whit3rd wrote:
On Tuesday, August 18, 2015 at 7:02:20 PM UTC-7, Jeff Liebermann wrote:
On Tue, 18 Aug 2015 16:58:50 -0700 (PDT), whit3rd <whit3rd@gmail.com
wrote:

... some greases are intended for electrical conduction in thin
films (they 'break down' at millivolts, and don't even get hot).
http://store.caig.com/s.nl/sc.2/category.185/.f
I've used this grease on rotating connections, at 40A it's just like
a solid wire connection.

Looks like aluminum dust, copper dust, graphite, and/or quartz(???).

Can't be, it's transparent. It's based on a semiconductive component, which is nonlinear:
insulating in bulk, but breaks down (in conductivity, not chemical nature) in
thin films under electrical stress. US Patent #4696832 has more info.

Never heard of that stuff, but if it's as you describe, it should be
quite useful. How conductive, I don't know. The patent isn't very
helpful:
http://www.google.com/patents/US4696832

Yeah, there's a high information cost... and there's more boosterism than
chemical physics in the sales lit. As to 'how conductive', the L260 variant
that I used doesn't have conductive particles, so it only conducts in thin films,
like rubbing parts would have around contact points. Because it is nonlinear,
'conductivity' is undefined (and the rubbing of bumpy surfaces mean
the film thickness is likewise indefinite). Variants on this lubricant
are recommended for slide potentiometers, I see.

The admixture of conductive particles would make a grease conduct electricity,
but that would be unsafe in electrical panels (and the intended uses include busbars).
It would decalibrate potentiometers, too. Because metallic particles would
constitute dissimilar metals in my mechanism, I didn't want to use such a grease.
Click to expand...

MMMMMMMMMMMMMM

use the artist's paintbrush not the zerkgun ....
 
On Wed, 19 Aug 2015 01:20:09 -0700 (PDT), whit3rd <whit3rd@gmail.com>
wrote:

Yeah, there's a high information cost... and there's more boosterism than
chemical physics in the sales lit. As to 'how conductive', the L260 variant
that I used doesn't have conductive particles, so it only conducts in thin films,
like rubbing parts would have around contact points. Because it is nonlinear,
'conductivity' is undefined (and the rubbing of bumpy surfaces mean
the film thickness is likewise indefinite). Variants on this lubricant
are recommended for slide potentiometers, I see.

The admixture of conductive particles would make a grease conduct electricity,
but that would be unsafe in electrical panels (and the intended uses include busbars).
It would decalibrate potentiometers, too. Because metallic particles would
constitute dissimilar metals in my mechanism, I didn't want to use such a grease.
Click to expand...

If the stuff works as you describe, then it should change conductivity
from a bad insulator to a marginal conductor when pressure is applied.
That got my interest because I have an application for a cheap
pressure sensing system, that will work with rollers and gears. In
theory, I could monitor the conductivity between meshed gears, which
would give me an indication of the applied pressure or changes in
pressure.

However, I don't think it works the way you suggest[1]. The grease
simply prevents surface oxidation and displaces electrolytes to reduce
galavanic corrosion if the mating surfaces are dissimilar meatals.
Doping it with conductive particles also helps reduce galvanic
corrosion. When I read the vague and misleading promotional
literature from that point of view, the claims seems to make sense.

On the other foot, there are specialized greases that allegedly work
the way you describe. I found a hint at:
<https://www.linkedin.com/grp/post/1786018-215513373>
but could not find any specifics. I'll dig more later. I also
haven't had time to read through the patents yet but I'll get to it
this weekend.


[1] increased pressure => thin film => increased conductivity

--
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
 
In article <4pn7tadlnqfpausst843g6um6sicg70kim@4ax.com>,
Jeff Liebermann <jeffl@cruzio.com> wrote:

Can't be, it's transparent. It's based on a semiconductive component, which is nonlinear:
insulating in bulk, but breaks down (in conductivity, not chemical nature) in
thin films under electrical stress. US Patent #4696832 has more info.

Never heard of that stuff, but if it's as you describe, it should be
quite useful. How conductive, I don't know.
Click to expand...

This material is better known as "Stabilant 22" (often used as
"Stabilant 22A", diluted in alcohol). Years ago, Stabilant 22A was
remarketed to the audiophile community (in small syringes, probably
with a huge mark-up) under the name "Tweek".

I've used it for quite a few years. It definitely seems to help
maintain electrical connections between contacts. Quite useful for
(e.g.) finger contacts on PCI cards... it has restored reliable
operation for cards which were intermittent, when a simple "unplug,
clean, and re-plug" cycling didn't help.
 
Jeff Liebermann <jeffl@cruzio.com> wrote:
On Wed, 19 Aug 2015 01:20:09 -0700 (PDT), whit3rd <whit3rd@gmail.com
wrote:

Yeah, there's a high information cost... and there's more boosterism than
chemical physics in the sales lit. As to 'how conductive', the L260 variant
that I used doesn't have conductive particles, so it only conducts in thin films,
like rubbing parts would have around contact points. Because it is nonlinear,
'conductivity' is undefined (and the rubbing of bumpy surfaces mean
the film thickness is likewise indefinite). Variants on this lubricant
are recommended for slide potentiometers, I see.

The admixture of conductive particles would make a grease conduct electricity,
but that would be unsafe in electrical panels (and the intended uses include busbars).
It would decalibrate potentiometers, too. Because metallic particles would
constitute dissimilar metals in my mechanism, I didn't want to use such a grease.

If the stuff works as you describe, then it should change conductivity
from a bad insulator to a marginal conductor when pressure is applied.
That got my interest because I have an application for a cheap
pressure sensing system, that will work with rollers and gears. In
theory, I could monitor the conductivity between meshed gears, which
would give me an indication of the applied pressure or changes in
pressure.

However, I don't think it works the way you suggest[1]. The grease
simply prevents surface oxidation and displaces electrolytes to reduce
galavanic corrosion if the mating surfaces are dissimilar meatals.
Doping it with conductive particles also helps reduce galvanic
corrosion. When I read the vague and misleading promotional
literature from that point of view, the claims seems to make sense.

On the other foot, there are specialized greases that allegedly work
the way you describe. I found a hint at:
https://www.linkedin.com/grp/post/1786018-215513373
but could not find any specifics. I'll dig more later. I also
haven't had time to read through the patents yet but I'll get to it
this weekend.


[1] increased pressure => thin film => increased conductivity
Click to expand...

I still have cramolin copper grease. I never used it on anything. Seems
like it had little conductivity with test leads.

Greg
 
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