How to Make Homemade Thermal Grease

By Lee Nichols

Updated September 28, 2017

Items you will need

  • No-grit toothpaste

  • Petroleum jelly

  • Bowl

  • Toothpick or spoon

  • Syringe

  • 5 grams diamond powder

  • 4 grams silicon grease

  • Zip-lock plastic bag

  • Dust mask

  • Syringe

Thermal grease is a compound that computer technicians use to help keep a computer processing unit cool. Air pockets form beneath heatsinks and video cards when they are installed in a processor; thermal grease fills the air pockets and increases thermal conductivity. Arctic Silver, Cool Laboratory and Shin-Etsu produce commercial thermal grease products, but you can make your own grease if you do not have a commercial product on hand. You should replace homemade thermal grease as soon as possible because the ingredients will break down and lessen its effectiveness.

Toothpaste Thermal Grease

Put toothpaste and petroleum jelly in a small bowl. Use a ratio of 75 percent toothpaste to 25 percent petroleum jelly. Use no-grit toothpaste because grit will interfere with heat transfer.

Mix the toothpaste and petroleum jelly with a toothpick. If you are making a large amount of grease, mix the ingredients with a spoon.

Fill a syringe with the mixture for ease of application.

Diamond Powder Thermal Grease

Put on a dust mask. Diamond dust is extremely dangerous if you inhale it, so always where breathing protection when working with it.

Put the diamond dust and silicone grease in a plastic bag. Close the bag tightly.

Mix the ingredients thoroughly by mashing on the bag with your fingers. Mix the compound until it is gooey, almost runny, but still holds its shape.

Put the compound in a syringe for application and storage.


Craft and hobby stores sell silicone grease.

You can purchase diamond powder on eBay; powder that is made from 25-carat diamonds works best.

Use a clean syringe, because any debris in the syringe can affect paste's heat conduction.


Do not buy silicone grease that contains zinc-oxide. Zinc-oxide will weaken the diamond powder's conductivity.

Store leftover diamond powder in a safe place, away from children.

Applying homemade thermal grease can void the warranty on your computer.