Thermal paste, also known as a thermal compound, is a thick, gooey paste that you use on your CPU or GPU so that it can make proper thermal contact with your heatsink. Without thermal paste, your processor would overheat very quickly as if you did not have a heatsink installed at all. But does thermal paste expire?
The short answer is yes, it unquestionably does. Just like food, thermal paste has a limited shelf life. It can go bad or, more commonly, dry out. Dry thermal paste cannot conduct heat very well, which is why you have to change your thermal paste at least once a year in the first place. This is in contrast to graphite thermal pads that can be used many times. But in terms of thermal conductivity, thermal pastes are still superior.
Another thing that people use on processors is liquid metal. Unlike thermal paste, liquid metal has to go directly onto the chip. It is applied under the metal heat spreader that you apply normal paste to. Liquid metal is very different from regular thermal paste and does not need to be changed unless it makes contact with a reactive surface, e.g. copper.
So does thermal paste expire after sitting for years? Most manufacturers say that thermal paste has a lifespan of three to five years. But just like with food, you can often use it long after it has expired. This largely depends on where it is stored and how, just like food.
If you wish to learn more about thermal paste, keep on reading. You will find out the dangers of using old or dry thermal paste as well as some other related things.
How Long Does Thermal Paste Stay Good For?
Since most people only apply thermal paste once every couple of years, it is very common that thermal paste dries out and goes bad. You should not feel bad if that happens to you. As long as your CPU temps are under control, there is little that you should worry about.
Thermal paste manufacturers say that it stays good for 3-5 years, but experience has shown that it depends. It depends on a number of factors, such as the temperature at which it is stored, humidity, packaging, and whether it has been opened.
You do not have to worry if you have some old thermal paste or are not sure of the date it was manufactured because you can test it. It is just like with food and drinks.
For example, chocolate bars typically have a shelf life of two years. But some types of chocolate can be eaten long after they have expired, while others might go bad after only a few months. Also, if the chocolate is kept in less-than-ideal conditions, it will go bad more quickly.
You can test your expired thermal paste by putting a small amount onto a metallic surface and trying to spread it to check if it is smooth. If it has any clumps or if it is watery, discard it. If you notice that only a part of the thermal paste is flaky or hard, you should still discard the tube because those are indicators that it is very old and not good.
It is super important that you always store your thermal paste properly. Twist the cap of the syringe tightly so that it does not dry out. Never pull the plunger back because it will make the paste react to air. If it came in a Ziploc bag, for example, most Arctic thermal pastes, put it back in for even better shielding from the elements. And it is best to keep it in a drawer.
Can Old Thermal Paste Cause Overheating?
Just like thermal paste that has not been changed in years on your CPU, using old, dry thermal paste can cause overheating. This does not have to be the case, though. Even if the thermal paste that you have is a bit old, if it has been kept in ideal conditions and has a normal consistency, then it is probably fine to use. Whatever the case may be, make sure that you closely monitor your temps before and after using it either way.
If you did not change your paste in three years or more, it is strongly recommended that you check your temps under a full load. If you see that your CPU goes above 85°C in games and rendering tasks, changing the thermal paste is one of the first things that you should do. More often than not, it will fix your overheating issues. Plus, it is very cheap to buy good thermal paste so don’t skimp on it.
What Happens If You Don’t Put Thermal Paste On CPU?
If you don’t put thermal paste on your CPU, it will overheat in a few seconds. It will either shut down or get permanently damaged. It does not matter how large your heatsink is, if you don’t put thermal paste between it and the CPU, it will make the CPU overheat.
Thermal paste is responsible for making your heatsink and CPU conduct heat. You might be lucky and your computer will work if you don’t put thermal paste, but it will kill the CPU in only a few weeks from the constant overheating. Seriously, do not skip putting thermal paste when installing a heatsink.
What can I use if I don’t have thermal paste?
Using substitutes for thermal paste is strongly discouraged. People have tested ridiculous things over the years since CPUs were first introduced. Everything from Nutella and mayonnaise to spray oil and lipstick. Cooler Master has once used Nutella just to showcase how powerful their new cooler is. They first heated it up because it gets thinner at high temps and then used a thermal paste syringe to apply it. They got a min temp of 21°C and max temp under full load was only 50°C. So it seems like using at least some kind of paste is better than going dry.
So, should you use Nutella then? No, do not use Nutella or any other paste that is not created to be used for thermal conductivity. You want to use high-quality thermal paste that will do its job, not something ridiculous. If you cannot get your hands on thermal paste for whatever reason, some people had luck using a mix of toothpaste and petroleum jelly in an 80/20 ratio.
While this is something that you should avoid at all costs because it can kill your CPU or motherboard, it does at least somewhat work. If you have to use this mixture, try to reapply it every 15 to 20 days just to make sure that it did not dry out.
Another relatively useful thing that you could use is diaper rash cream or something similar. Creams that have a high zinc oxide content are very thick and somewhat resemble real thermal paste. You can use these types of creams for a few months if you really can’t get your hands on actual thermal paste.
Once again, you should not use household items in place of real thermal paste. Doing that will most definitely void your warranty as well as create an electrical hazard if the household paste leaks.
Final Thoughts
Thermal paste is an essential part of a computer that must be used to have proper cooling. If you do not use thermal paste, your CPU will overheat and shut down or get permanently damaged. It may even cause a fire hazard if it is a very old CPU. You need to make sure that your thermal paste has the right consistency and is not dried out if you want to have proper cooling.
The answer to the question, “Does thermal paste expire?” is that it does, but it depends. Even though manufacturers say that its shelf life is somewhere around three to five years, it does not have to mean anything. The place where the thermal paste was stored as well as the conditions are the primary factors that affect it. Most people only apply thermal paste once every few years, so it is a very common issue.
If you have old paste, do not worry too much because you can always check if the paste is all right to use by using a small amount on a metallic surface and checking if the consistency is right. If you see any flakes, clumps, or if it has become very dry, throw it away. You do not want that stuff anywhere near your computer.
And if you do not have any thermal paste right now but need to use your computer urgently, you can try using a mixture of toothpaste and petroleum jelly. Please be very careful with this because it can dry out rather quickly or damage your components. Some people have even used mayonnaise in a pinch, but we strongly advise against it.
