Q&A for How to Apply Thermal Paste

All thermal paste does is transfer heat from the chip to the heatsink. The goal there being to prevent air bubbles from interfering with the transfer of energy.

Grab a cotton swab and dip it in a super small amount of isopropyl alcohol. Rub it on the paste residue and just slowly wear the dried paste away.

Yes, it fills in the gaps between the CPU and the heatsink. If there are air particles in there, your CPU won't cool off the right way. You really can't skip this step if you're building a PC or replacing a part.

Yes, it is possible to put on too much thermal paste, and if this happens, then it’ll end up on other components, which may decrease the effectiveness of the CPU, etc. However, it’s not harmful if this happens unless there is so much paste it’s seeping everywhere. Aim for a tiny blob about the size of a grain of rice, and no bigger. Clean off anything more.

If your CPU is running too hot, then the thermal paste is an important aspect of keeping down the temperature a bit and preventing the CPU from trying to throttle (slow down) in an attempt to cool itself. Most computer-build experts think that it’s not a great idea to skip adding thermal paste to a home-built computer. Occasionally, you’ll need to remove any dried-up paste and add new paste for the best performance, it's not just a one-off thing.

Thermal paste is an important part of keeping your CPU cooler and running effectively by improving the thermal conductivity and helping to decrease heat build-up.

Thermal paste is a paste that contains either silicone and zinc oxide (the cheaper versions), or silver/ceramic (the more expensive ones). Thermal paste is applied to the CPU and heat sinks to improve their ability to cool down and conduct heat efficiently. If you tend to overclock the computer, use a more expensive thermal paste containing silver, copper, or gold.

A cooler is a general term for the heat sink and the fan that sits on top of it. This 'cooler' does just that, cools the CPU.

Possibly. Thermal paste can sometimes harden, which greatly reduces its effectiveness. If this is the case, you will need to remove the old thermal paste, clean the surfaces and then re-apply new thermal paste. Note that, if you remove your CPU cooler for any reason, you should always apply new thermal paste. It could also be a problem with your CPU cooler itself. In this case, you would need to purchase a new CPU cooler, remove the old cooler, clean the old paste off of the CPU, apply new thermal paste, and then attach the new cooler. Finally, it could also be a problem with the airflow in your computer case. Make sure you have enough case fans and that they are not set up in a competing configuration.

It is never okay to use a CPU cooler without a layer of thermal paste between the cooler and the CPU. If you do, the heat will not transfer properly from the CPU to the cooler, and the CPU will eventually get hot enough to cause permanent damage.

No. Water and oils, as well as any other conducting liquids, should never be used.

No, not completely necessary. You don't need to sand the cooler, either. Most people don't do that step, as it is optional.

If it's not solidified. Some carbon-based ones last 8 years. Check the manufacture date on the tube.

Most stores that sell computer hardware and components will carry thermal paste.

I would clean the area with 90% or 70% alcohol, then reapply new paste, just to be safe.

No, there are no household substitutes for thermal grease that are safe and effective.

You should be able to power on the computer immediately. Make sure to monitor your CPU temperature to check the connection between the heatsink and the CPU.

I have had this issue previously and it was caused by a faulty power switch. If you unplug the power header on the motherboard, it should stop turning itself on. Of course, this means you don't have a power switch. You can either replace the power button or just manually bridge the motherboard pins every time to start the computer.

Yes, you should use a thermal compound. The liquid cooling system passes the coolant through a "water block," which is essentially a fluid-cooled heat sink. The surface of the water block must be thermally mated to the chip in the same manner as a heat sink, otherwise you'll be cooling the water block, but not the chip.

Find out why the CPU is overheating and correct the issue. For example, over clocking, no thermal paste, hardened thermal paste, a faulty CPU cooler, and inefficient case air circulation can all cause heat issues.

You can let it sit, but there really is no wait time for it to apply. My suggestion is that you should turn it on in order to make sure the computer is working properly and the temperatures are stable before leaving it for a time you need to use it. As long as you applied everything correctly, you should be fine.

Yes. However, if you do remove the cooler, it is recommended that you reapply new thermal paste before reinstalling the cooler.

You need to also install the heatsink, the piece that actually cools the CPU. The thermal paste is there to create conductivity between the CPU and heatsink, allowing the "coldness" to transfer from the heat sink the the CPU much more efficiently. It alone does nothing to cool your CPU.

Yes, you should. You can skip it if you only use your PC for browsing the web and checking email, but it is still recommended. If you are a gamer or want to overclock the CPU, then thermal paste is a must. After all, it is just a matter of a few bucks and a little effort.

No. Silicone sealant will likely seal the cooler to the processor, making its removal a serious damage risk. I would also wager that it will not be nearly as effective as the thermal paste.

No need to wait, it does not dry (or shouldn't). As the CPU warms up, the thermal compound will spread over the CPU.

Yes unless you are using a laptop, where the settings are carefully made by your manufacturer.