Mineral Oil as thermal grease...

S

Steve Wilson

Guest
A lot has been written about the requirement for thermal paste between
the cpu and the heat sink. Many different materials have been tried,
including the following and their temperature rise:

Butter 53.2C
Moisturizing cream 54C
Hair wax 56C
Toothpaste1C
Banana 58C
Paper 67.2C
Yellow cheese 67.9C

I focus on the ability of the material to provide a liquid interface
between the cpu and the heat sink. Even the regular thermal paste dries
out and must be replaced.

If a liquid is needed, why not use ordinary mineral oil? It\'s probably
better than butter, it doesn\'t dry out, and capilliary action will cause
it to form a uniform film between the cpu and the heat sink.

Any thoughts?

Here is an article describing more. Notice the first sentence includes an
oily interface material. Mineral oil, perhaps.

Thermal paste, or some oily thermal interface material, is necessary
because it fills in the microscopic imperfections that otherwise
trap air particles between the CPU and the heatsink, preventing the
CPU from properly cooling. Heat radiates outward from the CPU to the
heatsink, before eventually making its way to a fan where it
disperses; but, since air is a notoriously poor conductor of heat,
an outside element is needed to bridge the gap between the two
components.

Very often, assemblers and computer repairers do not have thermal
paste available. It is a fundamental component because it helps
cooling the CPU temperature down, lowering the thermal resistance
between the microprocessor and the heat sink.

Typically, PC-grade thermal paste supplies the necessary bridge, but
most oily household substances could temporarily suffice. A quick
Internet research reveals that many users have already taken it upon
themselves to test out a variety of substances for use, including
vegemite, Nutella, toothpaste, and American cheese.

Jorgen Elton Nilsen, of the Norwegian tech site Tek.No, tested all
of his substances using an Innovatek Kühlertester KT-3 simulator, an
industry-grade heater for analyzing the cooling capacity of air and
water cooling systems. Devices like Innovatek are better suited for
this task, as it\'s difficult to standardize the heat output of a CPU
solely through software. One can\'t simply activate the maximum heat
output by running a 3D-rendering demo because of the inherent bias:

there\'s no way to determine how much of the CPU\'s specified maximum
power rating is used up by the software.

Instead, Nilsen set up his Innovatek Kühlertester KT-3 with a heat
spreader and an Asus Triton 77 heatsink mounted on top of the CPU
and proceeded to test toothpaste, yellow cheese, hair wax,
moisturizing cream, butter, banana, and paper at intervals of 15
minutes under a 90-watt load.

The results will surprise you. In order from the most thermally
conductive to the least:

Butter 53.2C
Moisturizing cream 54C
Hair wax 56C
Toothpaste1C
Banana 58C
Paper 67.2C
Yellow cheese 67.9C

Taken at face value, it appears that the butter and the moisturizing
cream are the best short-term solutions, but truthfully, both
liquefied before the allotted 15-minute time frame came to a close.

Considering that a motherboard sits beneath a CPU inside a computer,
the liquefied oil runs the risk of spilling over onto underlying
electronics.

The best solutions turned out to be hair wax and toothpaste, which
exhibited a relatively low temperature without completely drying out
and cracking.

If you\'re impatient or under a tight deadline and need to squeeze in
a few hours of extra work, consider toothpaste or hair wax when
nothing else is available. When the time comes to replace it with
actual thermal paste, use a sharp edge to remove the dried-up
compound before applying a small amount of isopropyl alcohol to a
microfiber cloth and gently scrub off any excess particles. Suffice
it to say, computer-grade thermal paste eventually dries up as well,
needing to be periodically cleaned off and reapplied.

https://www.powerelectronicsnews.com/household-substitutes-for-cpu-
thermal-paste/

Also see
https://www.powerelectronicsnews.com/homemade-solutions-to-replace-cpu-
thermal-paste/
 
On Tuesday, August 18, 2020 at 1:27:49 PM UTC-7, Steve Wilson wrote:
A lot has been written about the requirement for thermal paste between
the cpu and the heat sink. Many different materials have been tried,
including the following and their temperature rise:

Butter 53.2C
Moisturizing cream 54C
Hair wax 56C
Toothpaste1C

Missing digit? 54C sound more reasonable.
 
On Tuesday, August 18, 2020 at 1:46:01 PM UTC-7, Edward Lee wrote:
On Tuesday, August 18, 2020 at 1:27:49 PM UTC-7, Steve Wilson wrote:
A lot has been written about the requirement for thermal paste between
the cpu and the heat sink. Many different materials have been tried,
including the following and their temperature rise:

Butter 53.2C
Moisturizing cream 54C
Hair wax 56C
Toothpaste1C
Missing digit? 54C sound more reasonable.

I meant 51C.
 
On Tuesday, August 18, 2020 at 1:27:49 PM UTC-7, Steve Wilson wrote:
A lot has been written about the requirement for thermal paste between
the cpu and the heat sink. Many different materials have been tried,
including the following and their temperature rise:

Butter 53.2C
Moisturizing cream 54C
Hair wax 56C
Toothpaste1C
Banana 58C
Paper 67.2C
Yellow cheese 67.9C

I did use some motor oil for my CPU, while waiting for the mail order grease.
 
On Tuesday, August 18, 2020 at 4:47:55 PM UTC-4, Edward Lee wrote:
On Tuesday, August 18, 2020 at 1:46:01 PM UTC-7, Edward Lee wrote:
On Tuesday, August 18, 2020 at 1:27:49 PM UTC-7, Steve Wilson wrote:
A lot has been written about the requirement for thermal paste between
the cpu and the heat sink. Many different materials have been tried,
including the following and their temperature rise:

Butter 53.2C
Moisturizing cream 54C
Hair wax 56C
Toothpaste1C
Missing digit? 54C sound more reasonable.

I meant 51C.

I believe you list the temperatures as the temperature of the CPU, in other words, the total temperature rise from ambient rather than the temperature across the CPU heat sink interface, right?

While this data may have some comparative value it would be best if provided in comparison to using a reasonable quality heat sink grease installed properly. This would allow an estimate of the actual thermal resistance or a better comparison to a properly installed heat sink.

All the other tests were presented in a temperature ranked order. If Toothpaste is 51 °C, why would it be the only entry out of place? Could it be 57 °C?

--

Rick C.

- Get 1,000 miles of free Supercharging
- Tesla referral code - https://ts.la/richard11209
 
On Tuesday, August 18, 2020 at 4:50:45 PM UTC-4, Edward Lee wrote:
On Tuesday, August 18, 2020 at 1:27:49 PM UTC-7, Steve Wilson wrote:
A lot has been written about the requirement for thermal paste between
the cpu and the heat sink. Many different materials have been tried,
including the following and their temperature rise:

Butter 53.2C
Moisturizing cream 54C
Hair wax 56C
Toothpaste1C
Banana 58C
Paper 67.2C
Yellow cheese 67.9C

I did use some motor oil for my CPU, while waiting for the mail order grease.

I expect that to work pretty well. The only downside would be that it would flow out more easily than grease. Otherwise they are the same thing and the oil would do a better job of being as thin a layer as possible.

--

Rick C.

+ Get 1,000 miles of free Supercharging
+ Tesla referral code - https://ts.la/richard11209
 
On Tuesday, August 18, 2020 at 1:27:49 PM UTC-7, Steve Wilson wrote:
A lot has been written about the requirement for thermal paste between
the cpu and the heat sink. Many different materials have been tried...

If a liquid is needed, why not use ordinary mineral oil?

One reason: some printed circuit material is not oil-tolerant (it swells the epoxy type,
but porcelain-on-steel is fine with oil).
Silicone oil (and there are very-high-viscosity variants) is typically
in the high-temperature thermal pastes.
 
On Tue, 18 Aug 2020 20:27:41 GMT, Steve Wilson <spam@me.com> wrote:

A lot has been written about the requirement for thermal paste between
the cpu and the heat sink. Many different materials have been tried,
including the following and their temperature rise:

Butter 53.2C
Moisturizing cream 54C
Hair wax 56C
Toothpaste1C
Banana 58C
Paper 67.2C
Yellow cheese 67.9C

I focus on the ability of the material to provide a liquid interface
between the cpu and the heat sink. Even the regular thermal paste dries
out and must be replaced.

I don\'t think silicone grease dries out.

If the surfaces are properly flat, any oily thing, like vaseline
maybe, will do. The important thing is to keep the interface flat, and
not space the metal surfaces apart. Cheese and banana and paper won\'t
flow and squash down to microinch gaps.

If fill particles increase the gap much, they are harmful.

Air bubbles are bad too.
 
whit3rd wrote:

==============
If a liquid is needed, why not use ordinary mineral oil?

One reason: some printed circuit material is not oil-tolerant (it swells the epoxy type,

** Nonsense.


Silicone oil (and there are very-high-viscosity variants) is typically
in the high-temperature thermal pastes.

** Silicone lubricating grease migrates rapidly from between semiconductors and their heatsinks that get unusually hot - say 100C or more.

Once widely used to improve heat transfer, it is now never seen having been replaced by mixtures containing thermally conducting fillers - ZnO and the like.

One locally produced power amplifier ( Jands SR3000 ) had 24 x TO3 devices mounted on 4 live heatsinks with no insulators to improve cooling - but by error used regular bearing grease instead of thermal compound.

After a year or so of service, output stages began failing due to the fact there was NO grease under the TO3s. It had spread itself all over the rest of the heatsink instead.

Knowing the designer, I rang and informed him. His instant reaction was \"bullshit !! - we use proper thermal grease\".

An hour later I got a call back with apology, it was indeed bearing grease and a whole batch of amps had to be disassembled an re-done with the good stuff.

Fact: the same company\'s in house service department KNEW about the issue, obtained real thermal grease for their work and did NOT tell others.


..... Phil
 
On Tuesday, August 18, 2020 at 6:00:00 PM UTC-4, John Larkin wrote:
On Tue, 18 Aug 2020 20:27:41 GMT, Steve Wilson <spam@me.com> wrote:

A lot has been written about the requirement for thermal paste between
the cpu and the heat sink. Many different materials have been tried,
including the following and their temperature rise:

Butter 53.2C
Moisturizing cream 54C
Hair wax 56C
Toothpaste1C
Banana 58C
Paper 67.2C
Yellow cheese 67.9C

I focus on the ability of the material to provide a liquid interface
between the cpu and the heat sink. Even the regular thermal paste dries
out and must be replaced.

I don\'t think silicone grease dries out.

Grease doesn\'t dry, that means loses water which grease doesn\'t have in the first place. But it does ooze out gradually which has the same effect.


If the surfaces are properly flat, any oily thing, like vaseline
maybe, will do. The important thing is to keep the interface flat, and
not space the metal surfaces apart. Cheese and banana and paper won\'t
flow and squash down to microinch gaps.

If fill particles increase the gap much, they are harmful.

Air bubbles are bad too.

Yup, anything that spaces the heat sink from contact with the CPU adds thermal resistance, but by how much? If adding particles of highly heat conductive material increases the overall conductivity, even if it widens the gap slightly it will still improve the net conduction.

--

Rick C.

-- Get 1,000 miles of free Supercharging
-- Tesla referral code - https://ts.la/richard11209
 
On Tuesday, 18 August 2020 23:21:41 UTC+1, Ricketty C wrote:
On Tuesday, August 18, 2020 at 6:00:00 PM UTC-4, John Larkin wrote:
On Tue, 18 Aug 2020 20:27:41 GMT, Steve Wilson <spam@me.com> wrote:

A lot has been written about the requirement for thermal paste between
the cpu and the heat sink. Many different materials have been tried,
including the following and their temperature rise:

Butter 53.2C
Moisturizing cream 54C
Hair wax 56C
Toothpaste1C
Banana 58C
Paper 67.2C
Yellow cheese 67.9C

I focus on the ability of the material to provide a liquid interface
between the cpu and the heat sink. Even the regular thermal paste dries
out and must be replaced.

I don\'t think silicone grease dries out.

Grease doesn\'t dry, that means loses water which grease doesn\'t have in
the first place. But it does ooze out gradually which has the same effect.


If the surfaces are properly flat, any oily thing, like vaseline
maybe, will do. The important thing is to keep the interface flat, and
not space the metal surfaces apart. Cheese and banana and paper won\'t
flow and squash down to microinch gaps.

If fill particles increase the gap much, they are harmful.

Air bubbles are bad too.

Yup, anything that spaces the heat sink from contact with the CPU adds
thermal resistance, but by how much? If adding particles of highly heat
conductive material increases the overall conductivity, even if it widens
the gap slightly it will still improve the net conduction.

I bought some of this: Arctic MX4 www.amazon.co.uk/gp/product/B07L9BDY3T
last year and was happy with the results.
The manufacturers seem very coy about the filler which they describe
as \"carbon microparticles\" which are not electrically conducting.
The safety data sheet shows that it is filled with a mixture of
diamond and alumina. Why don\'t they just say so?

John
 
On Tue, 18 Aug 2020 15:40:12 -0700 (PDT), jrwalliker@gmail.com wrote:

On Tuesday, 18 August 2020 23:21:41 UTC+1, Ricketty C wrote:
On Tuesday, August 18, 2020 at 6:00:00 PM UTC-4, John Larkin wrote:
On Tue, 18 Aug 2020 20:27:41 GMT, Steve Wilson <spam@me.com> wrote:

A lot has been written about the requirement for thermal paste between
the cpu and the heat sink. Many different materials have been tried,
including the following and their temperature rise:

Butter 53.2C
Moisturizing cream 54C
Hair wax 56C
Toothpaste1C
Banana 58C
Paper 67.2C
Yellow cheese 67.9C

I focus on the ability of the material to provide a liquid interface
between the cpu and the heat sink. Even the regular thermal paste dries
out and must be replaced.

I don\'t think silicone grease dries out.

Grease doesn\'t dry, that means loses water which grease doesn\'t have in
the first place. But it does ooze out gradually which has the same effect.


If the surfaces are properly flat, any oily thing, like vaseline
maybe, will do. The important thing is to keep the interface flat, and
not space the metal surfaces apart. Cheese and banana and paper won\'t
flow and squash down to microinch gaps.

If fill particles increase the gap much, they are harmful.

Air bubbles are bad too.

Yup, anything that spaces the heat sink from contact with the CPU adds
thermal resistance, but by how much? If adding particles of highly heat
conductive material increases the overall conductivity, even if it widens
the gap slightly it will still improve the net conduction.

I bought some of this: Arctic MX4 www.amazon.co.uk/gp/product/B07L9BDY3T
last year and was happy with the results.
The manufacturers seem very coy about the filler which they describe
as \"carbon microparticles\" which are not electrically conducting.

Soot?

The safety data sheet shows that it is filled with a mixture of
diamond and alumina. Why don\'t they just say so?

John

I\'ve used diamond-particle filled silicone grease. It\'s not better
than the usual Dow stuff. The particles added more spacing than their
thermal conductivity (or price!) justified.

The usual Dow 340 filled grease, when modest pressure is applied,
oozes down to below 100 microinch gap, which was my measurement
resolution.

If you need electrical insulation, aluminum nitride + Dow is great.
 
Ricketty C wrote:

On Tuesday, August 18, 2020 at 4:47:55 PM UTC-4, Edward Lee wrote:
On Tuesday, August 18, 2020 at 1:46:01 PM UTC-7, Edward Lee wrote:
On Tuesday, August 18, 2020 at 1:27:49 PM UTC-7, Steve Wilson wrote:
A lot has been written about the requirement for thermal paste
between the cpu and the heat sink. Many different materials have been
tried, including the following and their temperature rise:

Butter 53.2C
Moisturizing cream 54C
Hair wax 56C
Toothpaste1C
Missing digit? 54C sound more reasonable.

I meant 51C.

Oh, DARN it! I thought you had found the holy grail of thermal conductors!

Jon
 
onsdag den 19. august 2020 kl. 01.03.31 UTC+2 skrev John Larkin:
On Tue, 18 Aug 2020 15:40:12 -0700 (PDT), jrwalliker@gmail.com wrote:

On Tuesday, 18 August 2020 23:21:41 UTC+1, Ricketty C wrote:
On Tuesday, August 18, 2020 at 6:00:00 PM UTC-4, John Larkin wrote:
On Tue, 18 Aug 2020 20:27:41 GMT, Steve Wilson <spam@me.com> wrote:

A lot has been written about the requirement for thermal paste between
the cpu and the heat sink. Many different materials have been tried,
including the following and their temperature rise:

Butter 53.2C
Moisturizing cream 54C
Hair wax 56C
Toothpaste1C
Banana 58C
Paper 67.2C
Yellow cheese 67.9C

I focus on the ability of the material to provide a liquid interface
between the cpu and the heat sink. Even the regular thermal paste dries
out and must be replaced.

I don\'t think silicone grease dries out.

Grease doesn\'t dry, that means loses water which grease doesn\'t have in
the first place. But it does ooze out gradually which has the same effect.


If the surfaces are properly flat, any oily thing, like vaseline
maybe, will do. The important thing is to keep the interface flat, and
not space the metal surfaces apart. Cheese and banana and paper won\'t
flow and squash down to microinch gaps.

If fill particles increase the gap much, they are harmful.

Air bubbles are bad too.

Yup, anything that spaces the heat sink from contact with the CPU adds
thermal resistance, but by how much? If adding particles of highly heat
conductive material increases the overall conductivity, even if it widens
the gap slightly it will still improve the net conduction.

I bought some of this: Arctic MX4 www.amazon.co.uk/gp/product/B07L9BDY3T
last year and was happy with the results.
The manufacturers seem very coy about the filler which they describe
as \"carbon microparticles\" which are not electrically conducting.

Soot?

The safety data sheet shows that it is filled with a mixture of
diamond and alumina. Why don\'t they just say so?

John

I\'ve used diamond-particle filled silicone grease. It\'s not better
than the usual Dow stuff. The particles added more spacing than their
thermal conductivity (or price!) justified.

The usual Dow 340 filled grease, when modest pressure is applied,
oozes down to below 100 microinch gap, which was my measurement
resolution.

you can also get indium sheets, https://customthermoelectric.com/tf-if150150-indiumfoil-tim-150-x-150mm.html

or use liquid metal like gallium, it melts at ~30\'C but it eats aluminium so
you need a copper spreader
 
John Larkin wrote:

===================

The manufacturers seem very coy about the filler which they describe
as \"carbon microparticles\" which are not electrically conducting.

Soot?

** Huh ? Since when is that non conducting ??

Anecdote:

Once had to service a tube amp \"Marshall\" for crackling noises.
The thing looked almost new, inside and out. None of the tubes were making the noises, but there were signs of leakage here and there.

On a hunch, I lifted the PCB and found the whole underside covered in clumps of soot.

WTF ???

Found out later the amp had been stored in garage while there had been a fire covering everything in soot. The owner later had spent hours cleaning his Marshall, inside and out to get rid of it but forgot about the UNDERSIDE of the PCB.


..... Phil
 
On 2020-08-18, Ricketty C <gnuarm.deletethisbit@gmail.com> wrote:
On Tuesday, August 18, 2020 at 6:00:00 PM UTC-4, John Larkin wrote:
On Tue, 18 Aug 2020 20:27:41 GMT, Steve Wilson <spam@me.com> wrote:

A lot has been written about the requirement for thermal paste between
the cpu and the heat sink. Many different materials have been tried,
including the following and their temperature rise:

Butter 53.2C
Moisturizing cream 54C
Hair wax 56C
Toothpaste1C
Banana 58C
Paper 67.2C
Yellow cheese 67.9C

I focus on the ability of the material to provide a liquid interface
between the cpu and the heat sink. Even the regular thermal paste dries
out and must be replaced.

I don\'t think silicone grease dries out.

Grease doesn\'t dry, that means loses water which grease doesn\'t have in the first place. But it does ooze out gradually which has the same effect.

oil-based paint, and contact adhesive (aka rubber cement) both dry without losing any water.














If the surfaces are properly flat, any oily thing, like vaseline
maybe, will do. The important thing is to keep the interface flat, and
not space the metal surfaces apart. Cheese and banana and paper won\'t
flow and squash down to microinch gaps.

If fill particles increase the gap much, they are harmful.

Air bubbles are bad too.

Yup, anything that spaces the heat sink from contact with the CPU adds thermal resistance, but by how much? If adding particles of highly heat conductive material increases the overall conductivity, even if it widens the gap slightly it will still improve the net conduction.

--
Jasen.
 
Steve Wilson <spam@me.com> wrote:
A lot has been written about the requirement for thermal paste between
the cpu and the heat sink. Many different materials have been tried,
including the following and their temperature rise:

Butter 53.2C
Moisturizing cream 54C
Hair wax 56C
Toothpaste1C
Banana 58C
Paper 67.2C
Yellow cheese 67.9C

I focus on the ability of the material to provide a liquid interface
between the cpu and the heat sink. Even the regular thermal paste dries
out and must be replaced.

If a liquid is needed, why not use ordinary mineral oil? It\'s probably
better than butter, it doesn\'t dry out, and capilliary action will cause
it to form a uniform film between the cpu and the heat sink.

Any thoughts?

Here is an article describing more. Notice the first sentence includes an
oily interface material. Mineral oil, perhaps.

Thermal paste, or some oily thermal interface material, is necessary
because it fills in the microscopic imperfections that otherwise
trap air particles between the CPU and the heatsink, preventing the
CPU from properly cooling. Heat radiates outward from the CPU to the
heatsink, before eventually making its way to a fan where it
disperses; but, since air is a notoriously poor conductor of heat,
an outside element is needed to bridge the gap between the two
components.

Very often, assemblers and computer repairers do not have thermal
paste available. It is a fundamental component because it helps

Sorry, if you don\'t have the basic supplies or tools for computer repair,
you\'re not an assembler let alone a repair tech.
 
On Wed, 19 Aug 2020 05:54:29 -0000 (UTC), Jasen Betts
<jasen@xnet.co.nz> wrote:

On 2020-08-18, Ricketty C <gnuarm.deletethisbit@gmail.com> wrote:
On Tuesday, August 18, 2020 at 6:00:00 PM UTC-4, John Larkin wrote:
On Tue, 18 Aug 2020 20:27:41 GMT, Steve Wilson <spam@me.com> wrote:

A lot has been written about the requirement for thermal paste between
the cpu and the heat sink. Many different materials have been tried,
including the following and their temperature rise:

Butter 53.2C
Moisturizing cream 54C
Hair wax 56C
Toothpaste1C
Banana 58C
Paper 67.2C
Yellow cheese 67.9C

I focus on the ability of the material to provide a liquid interface
between the cpu and the heat sink. Even the regular thermal paste dries
out and must be replaced.

I don\'t think silicone grease dries out.

Grease doesn\'t dry, that means loses water which grease doesn\'t have in the first place. But it does ooze out gradually which has the same effect.

oil-based paint, and contact adhesive (aka rubber cement) both dry without losing any water.

Both will form thermally insulating layers.

The paint would be OK if it\'s still wet and flowing when the surfaces
are clamped. I guess the interior bits would dry eventually. Sounds
messy.



--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard
 
Regular troll...

--
Phil Allison <pallison49@gmail.com> wrote:

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John Larkin wrote:

===================


The manufacturers seem very coy about the filler which they describe
as \"carbon microparticles\" which are not electrically conducting.

Soot?


** Huh ? Since when is that non conducting ??

Anecdote:

Once had to service a tube amp \"Marshall\" for crackling noises.
The thing looked almost new, inside and out. None of the tubes were making the noises, but there were signs of leakage here and there.

On a hunch, I lifted the PCB and found the whole underside covered in clumps of soot.

WTF ???

Found out later the amp had been stored in garage while there had been a fire covering everything in soot. The owner later had spent hours cleaning his Marshall, inside and out to get rid of it but forgot about the UNDERSIDE of the PCB.


.... Phil
 
On 2020-08-22, John Doe <always.look@message.header> wrote:
> Regular troll...

You claim to be regular without displaying any evidence thereof.

--
Jasen.
 

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