Final lapping with Arctic Silver sounds OK but...

[Xalista]

if you use AS as a lubricant during the final lapping you still get a little alu and grit in the small imperfections. I suggest (haven't tried this) cleaning the HS with water (or alcohol) after the final lapping and then doing it again with AS, but not on gritpaper but on a piece of glas. You won't be making the surface any more smoot, but you can be sure that there is only AS in the small imperfections.

[Colin]

Water or alcohol won't clean the microscopic surface imperfections, that's why the final lap should be done with Artic Silver. Take a look here http://www.arcticsilver.com/thermal_interface_basics.htm .

[GERRY136]

why couldnt someone take a brand new heatsink to a local millwork shop and have them do whatever with precision metal tools to get the base microscopically smooth? couldnt cost more than a good heat sink right? then u have no worries. what do ya think?