Thermal Paste Question!?

If you had perfect mating surfaces ( perfect meaning theoretically ideal.. probably impossible in reality).. then the metal surface on the CPU would have a perfect surface mate to the heat sink.

Since we can't afford perfect, the microscopic gaps get filled in with a thermal paste, usually with a silver or other heat-conductive metal in the paste.

The old paste dries up. The old paste has the shape of the old heat sink surface, plus any distortion when the heat sink was removed. So, it is just a really bad surface to mount a heat sink on. Old, dried paste is actually worse than no paste at all.

( and both are pretty bad.)

You can use first aid alcohol wipes or alcohol prep pads like you'd use before an injection.

Better for leverage and chemical cleaning may be some combination of

-- tools: q-tips, coffee filters, toothpick (mechanical scraping), wood clothespin, wood pottery spatulas, nail polish remover sponges, lint-free eyeglass cloth, and more..

-- chemicals

**some might melt your tools or other plastic/ epoxy parts in the computer, so be very careful! **

isopropyl alcohol (any first aid), ethanol/ethyl alcohol - (paint thinner/cleaner) , brake cleaner, gun cleaner, acetone..

Use care, start in a tiny area, follow all instructions on each part and on the chemical, and mask the surrounding area with cotton, felt, or something.

And.. NO, a heavy coat of thermal is not better. Use just enough to coat the surface, no more. Throw away any left over unless you are going to use it today.

edit: added link or two in case you want a second opinion