Start in either a “figure 8” or circular motion begin to lightly sand the base of the heat sink. After several minutes, you will begin to notice that you are only sanding the outside edges of the heat sink and there doesn’t seem to be anything happening in the middle.

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 This is due to the extreme unevenness of the base (see I warned ya). Continue sanding with the 220 until you have removed any scratches and imperfections and have a uniform surface. You may need to change the paper at this point, but I didn’t worry as the pack of paper I purchased came with 2 sheets of 220 grit.

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Continue this until you have moved through all the different grits – you will begin to notice that the grooves and imperfections will become less apparent. NOTE: If you change grits too early, this procedure may become more difficult. I have found it easier to use higher grits on a uniform surface as opposed to using the same grit on an uneven surface. Let the sandpaper do the work for you.

When you are finished, you will get a very smooth and shiny surface. At this point you may choose to go with an 800, 1000, or 1600 grit paper. In my case, I chose to stop at the 600 grit..…Looked good to me – no more deep grooves for air pockets and debris to hide.

As another option, you can polish the base with either a piece of notebook paper or a very fine polishing compound. I chose to leave it as is. Be sure to give a final washing in clean water to remove any Aluminum dust and sandpaper residue. Set on a paper towel and dry overnight. Next day be sure to wipe the base with some alcohol to remove any further reside, attach your retention clip, remount the fan assembly, apply your thermal paste of choice and remount the HSF to your ZIF.

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