# does thermal paste expire ?



## NTM2003 (Apr 13, 2015)

Does thermal paste expire ?


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## Bill_Bright (Apr 13, 2015)

No!

AS LONG AS the cured bond between the mating surfaces is not broken, thermal paste will easily last 10 - 15 years or even longer. But if the bond is broken, either due to rough handling during transport, or from the user twisting the heat sink to see if still tight  then the mating surfaces must be thoroughly cleaned and a fresh new layer of TIM (thermal interface material) be properly applied.


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## NTM2003 (Apr 13, 2015)

It seemed to apply fine so hope it works


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## Batou1986 (Apr 13, 2015)

I assume we are talking about in the tube ?
If thats the case then yes it does expire.
I had a large tube of AS5 that started to separate after about 4 years, half of it was oily the other half was like dry paste.


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## NTM2003 (Apr 13, 2015)

OK mine was kinda dry but it came out hopefully it will hold for 2days


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## peche (Apr 13, 2015)

_*Do you mean a tube, flask or pillow?*_
yes it does expire, you can see on back panel, also can get some storage advice, also exp date, lot and other important advice, instructions...

*Already applied paste?*
It expires and also dries, or burns or degrades,  depending on computer usage, also about cooler, heatpipes coolers are well know for maintaining high temps, so this will make a bigger impact on TIM, compared to waterblocks that may reduce heat due cooling performance, but that's a little bit more complicated topic, also on some cases differences are minimal, 
Some pastes as Coollaboratory liquid PRO / Ultra, Arctic silver 5 for example are wll know for long lasting lives, 
Degrades its the better term for what really happens to TIM's due temps and cooling

Regards,


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## NTM2003 (Apr 13, 2015)

my cpu is running at 28-30c thermal status ok using real temp


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## NTM2003 (Apr 13, 2015)

this is just for 2 days order some more should be in 2 days


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## peche (Apr 13, 2015)

NTM2003 said:


> my cpu is running at 28-30c thermal status ok using real temp


that's a excellent temp no worries, i wonder you are using the stock TIM pre-applied with your cooler, 

Regards,


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## NTM2003 (Apr 13, 2015)

yes for now see my other thread on first build had problems with the h80i


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## NTM2003 (Apr 13, 2015)

http://www.techpowerup.com/forums/threads/first-build-log.211268/page-3#post-3268735


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## Bill_Bright (Apr 14, 2015)

@NTM2003 - Perhaps I misunderstood your question. I thought you were talking about TIM already applied, not TIM left in an opened tube. So to clarify, once properly applied, TIM does NOT expire *IF* the cured bond has not been broken! Big "if", yes. But there's no reason it would break under normal use.

If you were talking about TIM in an opened tube, then that TIM has been exposed to the air. It also has not gone through any heat/cool cycles so what is left unused in the tube _may_ become unusable - depending on the solvents used in that particular formula.

So the point is, you do not have to replace properly applied TIM just because x number of years have passed - again, if the bond remains unbroken.

There is a *common misconception* among enthusiasts who are not formally trained in electronics that because the "exposed" edges of TIM turns hard or becomes "crusty" that the product between the mating surfaces has somehow become ineffective. THAT IS NOT TRUE! Remember, the most efficient transfer of heat occurs with direct metal-to-metal contact of the mating surfaces.

The purpose of the TIM is ONLY to fill the microscopic pits and valleys in the mating surfaces to displace any insulating air that may have been trapped within. Years later, the TIM is still there and if the bond is unbroken, air cannot get in and occupy the same space. Therefore, the TIM does NOT need to be replaced just because years have passed - even if it dries out!

As an electronics technician since 1971 (see the link in my sig), I have personally worked on 15 year old radio communications systems where TIM used on solid state devices was still working perfectly even though the exposed TIM around the edges had turned brown, crusty and nasty looking.

See The Heatsink Guide: Info about thermal compound and note the following (my *bold* added), 





> Thermal compound normally does not get hard, it will stay sticky for years. But depending on the solvents used in the making of the compound, it may dry over the years. This is not a reason to worry; it will still do its job when dry, and *there is no reason to replace dried thermal compound.*



IF it was necessary to regularly replace TIM, don't you think the TIM makers would say so? After all, that would mean more money for them. But they don't say to regularly replace it because they know it is NOT necessary.


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## Vario (Apr 14, 2015)

Arctic Silver 5 7 years after application was still working fine on 939 system, also was fused so hard it was difficult to remove the heat sink fan!


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## Bill_Bright (Apr 14, 2015)

Vario said:


> Arctic Silver 5 7 years after application was still working fine on 939 system, also was fused so hard it was difficult to remove the heat sink fan!


Right! Note this is why, if you really need to remove the heatsink, it is recommended you run the computer a few seconds to warm the TIM up, then gently apply back and forth twisting actions to break it loose. That is, don't start yanking on it when cold.


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## peche (Apr 14, 2015)

Bill_Bright said:


> the TIM does NOT need to be replaced just because years have passed - even if it dries out!


i have my mind full of f*cks.... sorry for that  but explain me  this sir....


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## MrGenius (Apr 14, 2015)

peche said:


> i have my mind full of f*cks.... sorry for that  but explain me  this sir....


It's really simple actually. As long as there's no air, wet or dry does not matter. Nothing in TIM expires with time. Solvents may evaporate from it if exposed to heat and/or air, rendering it "less" useful for effective application. And oils may separate from solids, even if left sealed in long-term storage, but they can usually be remixed and used as normal if that happens.


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## peche (Apr 14, 2015)

let me figure out something…

TIM dries out, solvents, oil pigments and many more craps start to degrades, for long times… so … there is no need to replace it, it just will work for miracle…even when pigments, oils and ingredients are degrading, drying or already gone…

I completely understand what's made for, to help as a bridge between CPU's I.H.S. and fill out microscopic holes, valleys and imperfections between 2 surface that aren't 100% flat, so thermal interface material is made for help heat got fully transferred and preventing heat gaps on already counted imperfections… so by the time and years pass by, all thermal shits are degrading, because several facts and issues such as air contact, temps up and down, thermal cycles like normal PC use or extreme and insane use, all of this an many more things affects TIM performance, in positive and negative side, but the fact here is that paste is getting degraded day by day so time really matters,

some TIM may last more than other that’s another important fact, but time, use and also application method and quantity or amount of paste used are critical facts in the process,

I'm not telling her that paste may be replaced pretty often, but it has to be some day, to keep cooling performance at its finest,  

it's OK to say that old TIM will work fine, but how fine is working?

how do you know that old paste on several devices is not affecting performance?

I know that old paste can keep the work going*… but I do not agree on keep using the same old paste.*


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## MrGenius (Apr 14, 2015)

It's hard to say it better than has already been said. I believe in leaving it be forever, if it's still working...why fix it? How long it's been there, or how "degraded" it might be, doesn't concern me. It's actually far more stable over time/while in use than you might realize. It's only worth replacing if you want to upgrade to a higher quality TIM, and/or if you assume it wasn't properly applied(and you think you can apply TIM better).


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## NTM2003 (Apr 14, 2015)

I have had it on my PC for a day now and it runs cool at 28-31c so seems to be fine


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## Bill_Bright (Apr 14, 2015)

I don't see where all this cussing and obscenities help keep this discussion professional.



peche said:


> i have my mind full of f*cks.... sorry for that  but explain me  this sir....


I explained it in post #12 above. What are you not understanding?

The idea behind the TIM is to displace any air that may be trapped between the mating surfaces. Air is an insulator - you don't want an insulator there - you want something that conducts the heat. The ceramics or silver alloys (depending on formulas) in the TIM is what conducts the heat. Ceramics and silver alloys do not degrade or evaporate over time. They remain regardless what the other materials do so they are still doing their thing - that is, not allowing the insulating air to take their place.

Students of electronics are taught this in school. If you are not a formally trained electronics technician or EE, then this is not something you would necessarily know. And sadly, much mis-information has been posted by some who don't know what they are talking about - and then those falsehoods are spread and spread again until many believe they are true.

If you still refuse to accept this, look it up! Show us on the websites of your favorite TIM where they recommend regular replacement. Show us where they state their product looses effectiveness in x number years.

TIM is not like paint or other materials that are exposed to UV from the sun, or the harsh elements of the weather.



> how do you know that old paste on several devices is not affecting performance?


What? Because the computer is still working! And the computer is stable and the temps are still good. Because as an electronics technician for 45 years, I have seen very old electronics chugging along just fine with old TIM. Because silver and ceramic materials do not lose their heat transfer properties over time just because the materials that make the silver and ceramics spreadable dry out.

I say again, if you refuse to accept this, look it up! Then show us!



MrGenius said:


> It's hard to say it better than has already been said. I believe in leaving it be forever, if it's still working...why fix it? How long it's been there, or how "degraded" it might be, doesn't concern me. It's actually far more stable over time/while in use than you might realize. It's only worth replacing if you want to upgrade to a higher quality TIM, and/or if you assume it wasn't properly applied(and you think you can apply TIM better).


Right! And you need to replace it if the HSF was removed for any reason - such as before transporting the PC.

If you have seen temps rise over time, it is more likely because the fan is not spinning as fast as it did when new - which typically happens as bearings go through their natural wear and tear aging process. Other reasons are the ambient (room) temps rise. Voltage/current changes occur. And unless you actually wash the heatsink, grime, dust, skin oils and smoke particles from the kitchen (if not tobacco) will coat the heatsink (and everything that is exposed to the air too) and that also affects heat transfer efficiency.


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## NTM2003 (Apr 14, 2015)

I'm getting new thermal paste tomorrow so I be applying that tomorrow


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## Bill_Bright (Apr 14, 2015)

NTM2003 said:


> I'm getting new thermal paste tomorrow so I be applying that tomorrow


Why? You just said above you are getting 28-31C temps. That is nothing short of outstanding! Understand you risk destroying your CPU, RAM and other sensitive devices from ESD and mishandling every time you reach inside your case. Why risk it when there is absolutely no need, or benefit?


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## NTM2003 (Apr 14, 2015)

So then it should be fine when iget my cooler in next month


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## 64K (Apr 14, 2015)

NTM2003 said:


> So then it should be fine when iget my cooler in next month



It will be fine with the temps that you are running until you get your new cooler next month. Be sure to clean off all of the TIM from your CPU before applying new TIM. You can use rubbing alcohol and coffee filters since they are lint free. I use a 2 stage cleaning kit from Arctic Cooling.


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## NTM2003 (Apr 14, 2015)

I'm having a PC shop to install it for me


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## NTM2003 (Apr 14, 2015)

I'm having a PC shop to install it for me see my first build theard


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## 64K (Apr 14, 2015)

NTM2003 said:


> I'm having a PC shop to install it for me



Then they will know to clean the paste off of your CPU before applying new paste and your new cooler.


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## NTM2003 (Apr 14, 2015)

http://www.techpowerup.com/forums/threads/first-build-log.211268/page-3#post-3269190


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## Bill_Bright (Apr 14, 2015)

With the temps you reported above, you sure don't need to install a different cooler. In fact, there are many with water cooling who would love to be in upper 20s/lower 30s.

While water cooling may give you a few more degrees, it certainly will not improve your CPU's performance stability or longevity. And sadly, while water cooling is neat and fancy, and offers good bragging rights, it also requires significantly more routine maintenance and inspections - and as the system ages and the novelty wears off, you will have to _increase_ those inspections to ensure all the fittings are still tight, hoses have not become brittle, no leaks have developed and no mold is growing inside the system.


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## NTM2003 (Apr 14, 2015)

well I know I don't have to do overclocking with my cpu but I will like to so that's why I am going with that cooler


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## Bill_Bright (Apr 14, 2015)

Well, you have a huge amount of head room to compensate for all but extreme overclocking. But that is your choice. I don't need 16Gb of RAM in this computer either - but I wanted it, so I bought it.


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## peche (Apr 15, 2015)

Bill_Bright said:


> TIM is not like paint or other materials that are exposed to UV from the sun, or the harsh elements of the weather.


well maybe because of this ... im miss understanding things and facts


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## Mussels (Apr 15, 2015)

expire no, but get worse with age - yes.

i've had a new and old tube of the same thermal paste and had a 12C difference between them. once applied they degrade much slower than in the tube, i guess because they have no room to seperate.


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## Jetster (Apr 15, 2015)

You guys put way to much thought into thermal paste. If it looks good then use it


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## micropage7 (Apr 15, 2015)

if it changes, more thick, harder to spread, or you find something that unusual  like oil layer on that you should buy the new one


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## Bill_Bright (Apr 15, 2015)

> i've had a new and old tube of the same thermal paste and had a 12C difference between them. once applied they degrade much slower than in the tube, i guess because they have no room to separate.


As I clarified above in post #12, 





			
				Bill_Bright said:
			
		

> If you were talking about TIM in an opened tube, then that TIM has been exposed to the air. It also has not gone through any heat/cool cycles so what is left unused in the tube _may_ become unusable - depending on the solvents used in that particular formula.


This is NOT about old TIM left for years in an opened tube like a half empty bottle of plain white glue. It is about a properly applied application of TIM on a CPU where the cured bond is still intact.

And the problem is not so much that the contents of the opened tube have separated or even that it looses its effectiveness (silver is silver and ceramics are ceramics - whether old or new). But that the solvent and other materials that make the TIM easily spreadable may have evaporated so the old TIM can no longer be spread nice and thin across the flat surfaces. And we all know, or at least I hope we all know by now that too much TIM gets in the way and is counterproductive to an efficient transfer of heat.

It is like the plain white glue - when it is properly used and not abused or exposed to the elements, it will hold a chair together for a 100 years or longer. But with a half empty bottle, the remaining glue will become unusable in few months.



> You guys put way to much thought into thermal paste. If it looks good then use it


That's pretty much it!

And again, if your properly applied favorite TIM requires regular replacing simply due to the passing of a couple years,  please show us on the TIM's website where it says that.


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## tanvirnabi (Apr 16, 2015)

It seems to me that you can shake it . There is another option you can pump the  syringe in and out. Then  mix it again. There are more details but first you do this.


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## Bill_Bright (Apr 16, 2015)

I don't know about shaking to mix it up thoroughly because even the thin stuff is fairly thick. But you can "work" the tube (for TIM that comes in tubes) to mix it up. And many larger shops buy tubs of TIM than can be stirred and mixed up with a clean Popsicle/glue stick.  

My concern about pumping the contents of a syringe in and out would be contamination of the TIM. I suppose if careful about that, it would work.


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