How to properly lap my heatsink?

[shurato]

My cpu temps on my AMD 1.33 is a rediculous 52c with light load...(I know it might not be very accurate). If I play any hardware intensive computer games, it will hard lock my system. I think its a heat related issue because if I open the case and blow a small fan into it, it won't lock up. Do you think it's because of my CPU overheating or possibly some other component such as the video or ram? (ati radeon 32ddr + crucial 512ddr)

Either way I think I need to lap my heatsink, its a thermalright sk6 and i remember reading a while back that they weren't too flat and some needed lapping.

 

[Soulkeeper]

get some silicon wet sand paper from your local hardware store
some fine grit
then get a peice of glass (IE: from a picture frame)
then just sand it perfectly smooth in yur kitchen sink or something
that's how i did mine

 

[ucdbiendog]

ive lapped about 5 or 6 different heatsinks, and heres how i did it every time:

get a mirror or piece of glass like form a picture frame.
then get 320, 400, 800, and 1500 grit sandpaper (1500 isnt neccessary, but its gets a REAL mirror finish)
tear each sheet in half, then tape it on to the mirror or glass, then take your heatsink and sand it in a figure 8 motion, so you dont get sanding grooves in the metal. start with 320, and use that grit until the bottom is completely flat. then sand with 400, 800, and 1500 grit for about 20 minutes in the same way until you get a nice finish. with the last grit, its best to finish it with a bit of water to get a smoother finish. hope this helps.

 

[shurato]

Thanks for the info....when you say the bottom is completely flat, you mean the heatsink right and not the sandpaper? Sorry if that is a stupid question. How do you know when to step up to the different grade sandpaper.