Problems cleaning heat sink...

[CrimsonChaos]

I'm trying to apply some Arctic Silver to a heatsink.

The problem is, the heatsink had a black patch of Thermal Interface Material on it already. I've been scrubbing it off and have it down the bare aluminum face, but it still is tainted a dull-grey (instead of bright silver). Is it OK to apply the Thermal Interface now, or does it have to be perfectly bright silver?

 

[CrimsonChaos]

Oh, also there's some very fine scratches on the facing of the heatsink (probably from me scrubbing) -- is this ok? Will the Arctic Silver fill in those scratches or have I screwed things up?

 

[Cheesetogo]

If the dull color and scratches bother you, very fine sandpaper should work. However, artic silver will fill in the cracks. A good idea is to smear artic sliver all over the heatsink and then wipe it off to fill the cracks up.

 

[CrimsonChaos]

Ok, I thought I might possibly have had some of that original TIM material stuck in the "grooves" of the heatsink. I was trying to make sure I didn't have to have it completely 100% cleaned out before applying the Arctic Silver.

 

[Jeff7181]

Originally posted by: CrimsonChaos
Ok, I thought I might possibly have had some of that original TIM material stuck in the "grooves" of the heatsink. I was trying to make sure I didn't have to have it completely 100% cleaned out before applying the Arctic Silver.

You'll never have it 100% cleaned out. It will always have a slightly discolored look after any TIM is applied because it's impossible to clean every last molecule out of the tiny pores of the metal.

As long as there's no residue that you can feel with your fingers, and you cleaned it up with isopropyl alcohol, it should be fine.

 

[Ausm]

I would lap it with fine sandpaper that will bring the luster back.

Ausm