Black smudges on the base of a copper heatsink

[viivo]

I've got a Volcano 12 sitting with some other stuff on a desk, and when I walked by earlier I saw black smudges that resemble fingerprints (the pattern looks like prints, but I've not touched the bottom.) It's new and hasn't been installed before or had any compound applied.

I've tried numerous times to clean it with alcohol but the smudges don't budge (thanks for the ridges from your crappy machining, Thermaltake.). I'd like to avoid lapping it for now, so any other suggestions would really be appreciated.

Thanks.

 

[Jaxidian]

I don't know how to get those off but you can probably still use it just fine.

Do the smudges have depth to them? If not, you're likely okay to just put your AS on it and use it as is. If they stick out, then I'd say lap it or return it. If they stick in (i.e. are grooves), then just put your AS on it and use it and expect temps about 2-3C higher.

 

[ericgl]

Acids from someone's hand possibly has caused a chemical reaction. The resulting salt would not have the thermal conductivity of pure copper. Suggest you sand it off with some 600 grit wet or dry just before installation.

 

[Davegod]

what about Brasso?

 

[Jaxidian]

Originally posted by: ericgl
Acids from someone's hand possibly has caused a chemical reaction. The resulting salt would not have the thermal conductivity of pure copper. Suggest you sand it off with some 600 grit wet or dry just before installation.

You're probably correct about the resulting film not having the thermal conductivity of pure copper. But I bet that this resulting film's thermal conductivity is the same as that of the film everywhere else where the copper has oxidized with the air. I'd say just slap your AS on it until you're ready to lap it.