How Long Does Thermal Paste Take to Dry? What Is Average Cure Time?

There’s a reason that thermal paste comes in a tube – it’s a liquid designed to be grease and sticky, with the right components to transfer heat while also being easily applied to any CPU surfaces. It’s also designed to be a gap-filler for microscopic pores and imperfections on a CPU’s HIS (IHS stands for integrated heat spreader. The IHS is the metal exterior lid of a CPU's processor) which would otherwise be filled by oxygen (which is notoriously bad at conducting thermal energy). Being a grease is the best choice for a gap-filler in this case unless… it dries out and becomes a solid. Sort of.

Dried or “cured” thermal paste can lead to serious cracking and a loss of heat transfer ability. Keep reading to learn more.

Does thermal paste ever cure?

So first of all, what is “cure” or “curing”? The term could sound strange if you’ve never heard it before. Curing is a word used with pastes, epoxies, and glues that essentially means “dries”. The difference being that “dry” implies that there’s no liquid in the substance anymore (i.e. it has evaporated). In fact, there is no curing agent (a compound that solidifies the substance) in thermal paste, so thermal paste “technically” doesn’t cure. But since these two seem pretty similar, we often use the term “cure” to describe how it is “dried” under heat.

The bigger question is: does thermal paste dry or “cure” easily? Yes and no. Thermal paste is designed to be a greasy compound and isn’t that easy to dry – Remember, it’s designed to be a “gap-filler” which means being able to take the shape of the gaps in the CPU’s IHS. A solid substitute, like a thermal pad, would be able to partially fill the imperfections but would still leave space in the micro-gaps for air to enter. So theoretically, no, it isn’t supposed to dry quickly.

However, within the realm of the thermal physics taking place inside a PC, thermal paste inevitably dries out. Thermal pastes tend to add organic solvents, which evaporate more quickly, in their formulation to achieve greasiness, leaving the thermal paste dry. Such formulation causes thermal paste to lose its ability to transfer heat and renders it inefficient.

We recommend using Kooling Monster KOLD-01 Thermal Paste because it employs no organic solvent in the formulation. Such design makes KOLD-01 more durable than other thermal pastes on the market.

What does it mean when thermal paste dries or cures? 

Initially, the thermal paste is a greasy substance and is allowed to fill in the micro-gaps on both the IHS and the face of the heatsink or waterblock. Once it fills that space, the cycles of turning your computer on and off and using your CPU to run programs generate heat and cause the thermal paste to dry partially. Which, now that it has entered the micro-gaps, provides a pathway for heat transfer. Drying occurs because the constant CPU usage cycles apply continuous heat to the substance.

Some other instances where drying or curing can occur are when you leave the thermal paste on the IHS too long without applying the heatsink or waterblock overtop of it. However, these instances are rare. If a thermal paste dries very quickly, it means that the quality is subpar – or that it has already expired. Think of toothpaste in this case – toothpaste dries quickly if exposed to heat; thus it is not a good substitute for thermal paste. Any thermal paste similar to toothpaste in this respect can be judged the same. (Learn more about Does thermal paste expire in tube? From practical and technical view points)

And of course, no matter how good your thermal paste is, using your computer will inevitably dry it out (though with higher quality thermal pastes, it may take a longer time). You should check your thermal paste every few months to make sure it hasn’t completely dried. If you notice it has, it’s time to reapply.

Average dry time and factors that impact it

Unlike for say… water, the formula for thermal paste differs and as such so does the drying time. Generally, thermal paste is not designed to cure or dry easily but some brands dry up in 3 months, whereas some can take years to dry. This all depends on several factors such as:

·       the formula of the thermal paste

·       the quality of the heatsink

·       sunlight exposure

·       location and condition of your computer

·       how you use your computer

Formulae notwithstanding, it essentially comes down to how much more heat – above what standard operation necessitates – you apply to your computer or CPU. We say formulae notwithstanding because even with the best cooling technology and a clean environment with good, cool, air circulation an organic solvent-based thermal paste will dry up eventually under standard operation and definitely faster if you’re gaming or doing process-intensive tasks like editing.

That said, we can control the other parts of the environment to ensure our thermal paste doesn’t dry out too fast.

How to prevent thermal paste dry out on CPU 

As mentioned earlier, there are several factors within your control to prevent your thermal paste from drying up too fast.

The first, and most important factor? Buy a good thermal paste. This one may seem simple, but too many people go with the first tube they see because they think it’s not an important part of their build. Then, over the next year they suffer from overheating problems and can’t figure out why. Do yourself a favor and buy a non-organic solvent-based thermal paste like Kooling Monster KOLD-01, which lasts long without drying and upholds the same efficiency all throughout.

Secondly, invest in a good quality heatsink or water-cooling system. This may seem arbitrary, but recall that the job of thermal paste, besides being a gap-filler, is to transfer heat from the CPU to the heatsink – which then promptly dissipates it. If the heatsink is unable to quickly dissipate heat, where does it go? Back through the thermal paste. And if the thermal paste takes in too much unnecessary heat, the rate at which it dries inevitably increases.

Thirdly, set up the environment around your computer to address any issues that might dry up your thermal paste. This means having ample air-conditioning in your space during the summer months, keeping your PC out of direct sunlight (especially during the summer months), and make sure that the space around your PC is free of dust or any other objects that could block airflow to your case. As well as helping to keep your thermal paste from drying, these tips also work great to prevent overheating.

And lastly, be mindful of the way you use your PC. Are you using it to simply watch Youtube videos or have you been running some CPU-heavy programs? High-quality gaming or video/photo editing are some good examples. If you’re getting a lot of heavy usage out of your computer, it might be a good idea to check your thermal paste once every few months.

FAQ

What factors can influence the drying time of thermal paste?

Drying time of thermal paste can be influenced by several factors, including the formula of the paste, quality of the heatsink, exposure to sunlight, location and condition of your computer, and the intensity of computer usage.

How does the quality of a heatsink affect the longevity of thermal paste?

The quality of a heatsink directly affects the longevity of thermal paste. A high-quality heatsink effectively dissipates heat, reducing unnecessary heat transfer back through the thermal paste, thus slowing down its drying rate and increasing its lifespan.

Why is a non-organic solvent-based thermal paste, like Kooling Monster KOLD-01, recommended?

Non-organic solvent-based thermal pastes like Kooling Monster KOLD-01 are recommended because they maintain efficiency over time and dry slower compared to other thermal pastes. They are more durable and efficient in transferring heat from the CPU to the heatsink.

What are some effective measures to prevent thermal paste from drying out too quickly?

To prevent thermal paste from drying quickly, purchase high-quality, non-organic solvent-based paste and a quality heatsink or water-cooling system. Maintain good air circulation around your PC, avoid direct sunlight exposure, and keep your computer dust-free. Regularly monitor and moderate CPU-intensive tasks.

How can heavy computer usage impact the lifespan of thermal paste?

Heavy computer usage generates more heat, speeding up the drying process of the thermal paste. Activities like high-quality gaming or video/photo editing put extra pressure on the CPU, leading to faster evaporation of the solvent in the paste, reducing its lifespan. Regular checks and replacements are advised.