Metal on CPU heatsink: What happened?

[Alir]

My CPU cooler has been gathering dust for some time. I was going to return it for RMA. Just noticed this on the CPU coolers metal square contact point part.

 

Any idea what it is? I thought it was rust or some kind of mold.

 

Tried to rub it off with a cloth and 99% isopropyl alcohol. Not all of it came off. Would this have any impact on cooling?

[PlayStation 2]

It looks like it probably just got... burnt? Shouldn't impact cooling to a non-negligible degree.

[W-L]

8 minutes ago, Alir said:

My CPU cooler has been gathering dust for some time. I was going to return it for RMA. Just noticed this on the CPU coolers metal square contact point part.

Any idea what it is? I thought it was rust or some kind of mold.

Tried to rub it off with a cloth and 99% isopropyl alcohol. Not all of it came off. Would this have any impact on cooling?

-PIC-

Looks to be nickel plated so possibly just tarnishing from contaminates, in general using some non abrasive metal polish will take that off of the nickel plating but it should not affect cooling in anyway.

[Alir]

2 hours ago, Dan Castellaneta said:

It looks like it probably just got... burnt? Shouldn't impact cooling to a non-negligible degree.

I don't understand how it could have gotten burnt. It has been sitting on my table for the past few days-weeks catching dust. It was fine before.

2 hours ago, W-L said:

Looks to be nickel plated so possibly just tarnishing from contaminates, in general using some non abrasive metal polish will take that off of the nickel plating but it should not affect cooling in anyway.

What do you mean? What does that actually mean it is?

[Alir]

I'm referring to the black spot only btw. The middle part is just scratches as my stupid self was trying to clean it with A4 paper before I came to my senses and just bought a £10 bottle of 99% isopropyl alcohol.

[W-L]

3 minutes ago, Alir said:

I don't understand how it could have gotten burnt. It has been sitting on my table for the past few days-weeks catching dust. It was fine before.

What do you mean? What does that actually mean it is?

Tarnish is just metal discoloring forming an oxide on the surface, polishing it will just remove a super thin layer to get rid of that discolored look. You can use it as is though since it will not affect performance. 

[Alir]

4 minutes ago, W-L said:

Tarnish is just metal discoloring forming an oxide on the surface, polishing it will just remove a super thin layer to get rid of that discolored look. You can use it as is though since it will not affect performance. 

Thanks for the explanation. I should probably remember that from GCSE Chemistry lol

[thekeemo]

7 minutes ago, W-L said:

Tarnish is just metal discoloring forming an oxide on the surface, polishing it will just remove a super thin layer to get rid of that discolored look. You can use it as is though since it will not affect performance. 

I mean the oxide might not conduct as well but for the most part no difference.

[W-L]

1 minute ago, thekeemo said:

I mean the oxide might not conduct as well but for the most part no difference.

Good point if it was a large spot then that could cause some problems. 

[Godlygamer23]

Moved to Air Cooling.

[Alir]

39 minutes ago, thekeemo said:

I mean the oxide might not conduct as well but for the most part no difference.

 

36 minutes ago, W-L said:

Good point if it was a large spot then that could cause some problems. 

 

That's not good......

 

This cooler was £70. Or £60. Whichever one.

[Alir]

Would using sandpaper be a good idea? To smooth it out and to take off a small few layers of metal and the oxide along with it?

[thekeemo]

Just now, Alir said:

 

 

That's not good......

 

This cooler was £70. Or £60. Whichever one.

Really fine sandpaper will fix it in fact it is often recommended to get that extra 2c of performance.

[Alir]

2 minutes ago, thekeemo said:

Really fine sandpaper will fix it in fact it is often recommended to get that extra 2c of performance.

lol finally I will have a use for that sandpaper I purchased 2 years ago to spray paint my 360 controller which got ruined.

[thekeemo]

Just now, Alir said:

lol finally I will have a use for that sandpaper I purchased 2 years ago to spray paint my 360 controller which got ruined.

Is it really really fine? 1200+

[Alir]

1 minute ago, thekeemo said:

Is it really really fine? 1200+

Does 220 GRIT count?

[thekeemo]

3 minutes ago, Alir said:

Does 220 GRIT count?

no

go 600 to 800 then 1200

you could go 2000 but that wont do as much

http://www.pcauthority.com.au/Feature/135165,atomic-guide-to-cpu-lapping.aspx/2

except you are doing it on the heatsink

[Alir]

1 minute ago, thekeemo said:

no

go 600 to 800 then 1200

you could go 2000 but that wont do as much

http://www.pcauthority.com.au/Feature/135165,atomic-guide-to-cpu-lapping.aspx/2

haha

[W-L]

4 minutes ago, Alir said:

Does 220 GRIT count?

>400 grit at least I would say super fine stuff like Keemo suggest would be the best, if you can get some polish though I would recommend that first, less aggressive steps first before going to more abrasive.

[thekeemo]

1 minute ago, W-L said:

>400 grit at least I would say super fine stuff like Keemo suggest would be the best, if you can get some polish though I would recommend that first, less aggressive steps first before going to more abrasive.

only thing im worried about with the abrasive would it "pitting" the surface.

[W-L]

1 minute ago, thekeemo said:

only thing im worried about with the abrasive would it "pitting" the surface.

The thermal paste should take care of any of that but of course using finer grits sandpaper is better. There are some blocks I've seen where they just milled the surface flat but still left a lot of the tooling marks which works but not ideal. 

[thekeemo]

2 minutes ago, W-L said:

The thermal paste should take care of any of that but of course using finer grits sandpaper is better. There are some blocks I've seen where they just milled the surface flat but still left a lot of the tooling marks which works but not ideal. 

I think that the abrasive pit would counter any benefits from removing the oxidization

But I would stick with RMA (or trading for my 212 evo) because lapping will get rid of any warranty..

[W-L]

3 minutes ago, thekeemo said:

I think that the abrasive pit would counter any benefits from removing the oxidization

It would add some scratch marks basically to the surface but the thermal paste should take up any of that but in general though the spotting is fairly small in this case, theoretically it shouldn't affect it.

 

[thekeemo]

Just now, W-L said:

It would add some scratch marks basically to the surface but the thermal paste should take up any of that but in general though the spotting is fairly small in this case, theoretically it shouldn't affect it.

 

Scratches?

Im thinking abrasive as in something with a PH..

[W-L]

37 minutes ago, thekeemo said:

Scratches?

Im thinking abrasive as in something with a PH..

Oh I'm just talking about regular polish for metal like brasso that just makes it shiny not something like acidic or even vinegar.