Loctite Adhesive, 19 g

The phase-Change Thermal Interface Compound is an effective means of transferring heat between two mechanically clamped, thermally conductive surfaces. The compound changes from a solid material to liquid at 60°C, as well as expanding in volume, thereby driving out any air that remains within the interface.

20% lower thermal resistance than typical thermal greases (0.03°C/W @20PSI, 0.02°C/W @100psi)
100% surface wetting
No runout, even in horizontal orientation
Silicone free
No shelf life
Fully reworkable
Clean, convenient applicator bar