How I "Lapped" my Heatsink Category  Hardware   Cooling Manufacturer  Any Product  Heatsink Article  Type  Blog Editor  Mark Hazlewood  Share    digg this! " In an ideal world you would want to lap both the heatsink and your CPU ... by lapping the heatsink you are making it completely flat in order to ensure a better contact.  "

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Lapping the Thermalright HR01+

After aquiring the last few parts of my recent build it was time to piece it together, before i did this i wanted to lap my CPU heatsink.  You are probably wondering what "Lapping" is.

Well here's a definition from Wiki: "Lapping is a machining operation, in which two surfaces are rubbed together with an abrasive between them, by hand movement or by way of a machine. Lapping can be used to obtain a specific surface roughness; it is also used to obtain very accurate surfaces, usually very flat surfaces."

The next thing you are probably wondering is "Why would you want to lap?".  Well, believe it or not, both your CPU and heatsink are not totally flat.  They can be slightly concave or slightly convex.  So when your CPU sits on top of your heatsink there is not a proper mating between them.  These little pits is the reason you need to use thermal paste, in order to fill in this spots to create a layer of conductivity.  So by lapping the heatsink you are making it completely flat in order to ensure a better contact. 

In an ideal world you would want to lap both the heatsink and your CPU, but lapping does void warranties and i wasn't about to take sandpaper to my £600+ processor ;). The idea is to use a flat surface and place sandpaper down, then drag the heatsink back and forth on the sandpaper to get a flat surface.  I ordered a lapping kit which had the basics in to help me. 

I got the Standard lapping kit (with glass) from Watercoolingshop.com. In the kit you get sandpaper sheets ranging from 400 grit, all the way up to 2500 grit. Here you can see the different sheets i got...

The first thing i did was get a sheet of MDF and lay it on the table. I took my sheet of glass and secured it to the MDF with Scotch tape.