'Avid6eek' from the world famous and always helpful PCSTATS Forums, has come up with a novel way to quickly lap the base of a heatsink for optimal heat transfer to bare-core processors. In this case Avid6eek has prepped the socket 939 Alpha Novatech PAL8150 heatsink for a dual core AMD Opteron which has had its Integrated HeatSpreader (IHS) popped off. The clever adaptation of a belt sander for lapping is a real time saver, and according to Avid6eek the shiny image below was accomplished in about 20min.
"Right now it is running at stock speeds (1.8Ghz) but I will be running it at at least 2.6Ghz as long as the motherboard supports a FSB of 289Mhz or higher. The processor is prime stable in the SFF box at those speeds. Now that I removed the IHS I may be able to push it higher. Lapping the old fashion way by hand just isn't my style. I have a belt sander that has a sanding wheel on the side. With double sided tape I just attach finer and finer pieces of sandpaper. I start with 800 grit > 1500 grit > 2000 grit > 2500 grit. I've got the process down so getting a shine like that takes around 20 minutes."