Lapping is refined, polished with the aimfor minimilize the level of coarseness of the surface of metal. Lapping could be done with the hands (manually) or could also use the machine. Lapping was also used to level the corner between two surfaces.

Materials that was needed:
Sandpaper (180, 400, 800, 1000, 1200, 1500, 2000)
Glass
Car Wax (scratch remover)
Water (as the lubricant)
Paper Towel (the second hand towel)
smooth towel (dont use a good clothes because of results dust lapping very dirty and was difficult to be cleaned)

Steps to lapping your HSF:

• preparing the sandpaper beginning with 220, 400, 800, 1000, 1200, 1500, 2000
• Prepare the level and stable place, glasses were the best according to me.
• From with the number 220, if his base was rough enough, like Big Typhoon I suggested began with 220, but rather low from that. (the exception: if heatsink very rough began with grit 180)
• With duct fermented or the wide isolation to stick the sandpaper on glasses.
• There were two types of the movement: the figure of eight and the figure 1. Figure of eight was the best because of the base heatsink will be more pressure.
• Not need to lapped very fast, the slow movement was enough to lapping until level.
• Stopped and moved to the bigger figure when HSF has been soft.
• Look also at the bottom of the sandpaper, confirmed did not have the small particle was supervised by paper because this small particle was enough to make the line when you lapping HSF.
• If the pile of metal already many, Give the water with the toothbrush to discard the pile.
• Lapping wet also good, but lapping dry will give the best results.
• Don’t be frightened the layer of copper was finished. Usually HSF is thick enough the copper base.

220

400

800

1000

1200

1500

2000, polished with Car Wax

After lapping the HSF, the temp of processor will decrease about 3-5 degrees

source from khurios2000 (chip forum)