# Time For Thermal Paste Set In?



## bumblebee_tuna

How long does it take for thermal paste to fully set in and create optimal heat transfer?  I wanna know if I have applied it right......


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## r3dh3adkid

Generally around a week


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## PC eye

One way to see a good bond after first applying the new paste is to let the system run for a few hours to heat things up. After that the bonding starts as the hsf and cpu start cooling. Generally a thermal coat takes upto two weeks to see a full bond. This will depend on how often the system is run.


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## ETSA

what are the procedure to reapply or set a new HSF?  Precautions and whatnot...


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## bumblebee_tuna

So would temps of 40-44C-ish be good temps per say after a fresh application?


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## Tayl

Is that temp reading when the machine is idle and hasn't been running for long? Or after a hard core usage and having been on for many hours? As my machine (spec in sig, similar to yours processor and HSF wise) normally idles at around 37C when having been on for many hours and after a good gaming session.


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## PC eye

ETSA said:


> what are the procedure to reapply or set a new HSF? Precautions and whatnot...


 
For reapplying a new coat you would first have to thoroughly clean off the old paste even if it was recently applied. This insures a clean surface for a good bond to take place. Something lint free like an old bandana or rag would be used there with some denatured alcohol for a quick dry.




bumblebee_tuna said:


> So would temps of 40-44C-ish be good temps per say after a fresh application?


 
Let's see when the cpu was first run on the new board here for much longer then 4hrs. the overheat protection shut the system down at 60C where it was set. That was right after applying AS5. This is why a good 4-5hrs. max is done first to allow the first cool down to start the bonding. Over the next few days the temps will start to drop to where you will see them normally if you have a good seal formed between cpu and sink.

This is where you have to keep a close look on temps to see if anything was done wrong. You can always reapply and reseat if the first coat bails out on you provided the cpu didn't cook in the process. On Asus boards the Probe I as well as Probe II are great to have onhand. SpeedFan is one freeware good for general use on a large variety of makes and models.


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## 4W4K3

Yup, PC eye has got it  It reminds me of bedding in new brakes. You want to heat them up, then cool them down, to ensure proper bedding/seating, etc. If you don't run them hot enough before they cool, then you wasted your time.


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## PC eye

On the old cars it was described as the "breakin time" for engines in new cars coming off the lot for the first time. That first time on the build here was a test to see if the overheat protection circuit would work. Upon reaching the threshold of 60C for the 65C max temp on the model cpu here the system saw the sudden shutdown.

 In a few days time the idle temp was about 33C with the Zalman CNS9500 model cpu cooler. In the last few months and after running all day and night the idle is roughly 35C with the max load on it seeing a top of 43C.


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## Tayl

Paste can make that much of a difference?


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## bumblebee_tuna

Breaks said:


> Paste can make that much of a difference?



I don't know.....  why don't you try putting your heatsink back without any......

Yes, it does......


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## apj101

> Paste can make that much of a difference?


its not really to bring overall temps down, its to prevent hot spots


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## PC eye

Breaks said:


> Paste can make that much of a difference?


 
 There can be a world of difference between different thermal compounds. One main difference between Artic Silver and others like Antec's own brand is the ceramic and silver level. The ceramic element sees a faster and more stable bond between the two surfaces with the silver level seeing better heat transfer. Antec stays soft and nothing more then grease while AS5 will firm up within a few days tops. Liquid Pro uses an updated method to see even more heat transfer off of the cpu to the hsf used.


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## Tayl

bumblebee_tuna said:


> I don't know.....  why don't you try putting your heatsink back without any......
> 
> Yes, it does......



And here is an example of an intelligent response to my question rather than your, well, it's quite evident what your's could be considered :



PC eye said:


> There can be a world of difference between different thermal compounds. One main difference between Artic Silver and others like Antec's own brand is the ceramic and silver level. The ceramic element sees a faster and more stable bond between the two surfaces with the silver level seeing better heat transfer. Antec stays soft and nothing more then grease while AS5 will firm up within a few days tops. Liquid Pro uses an updated method to see even more heat transfer off of the cpu to the hsf used.



Thank you for the info PC eye. I never actually relised the full effects of thermal paste, nor much of the information behind it to be honest. I've always been a 'spread it right, hope for the best' kind of person.

Wouldn't having more than one light coat be a good thing? I mean, the more you have on the more you have covered? Or is the thinner yet all covered the better? I really haven't got the foggiest with thermal paste details. As I've always wondered what the need for completely wiping an older paste from the cpu before applying a new one was.


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## PC eye

After a lengthy period of time any thermal compound can become too far dried out and simply turn brittle. That's when you start seeing cpus overheat since the compound is no longer flexible to expand and contract with the varying temps seen. When you reseat a hsf you clean off the dried up "worthless" compound completely in order to apply a fresh coat.

 When appying a new first time or repeat application you have to remember that is only a thin gap between cpu and sink. The compound is what fills in the gap and allows for the heat transfer after that bonds to both surfaces. If you realize that you apply enough immediately after the first application you will see how fast the drying process has started when you try pulling the sink off again. The recent or newly applied coat will ssssstretcchhhhhh as if you had used a form of epoxy glue.


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