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Whats a good polish for lapped copper HS

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Gremlin255

Member
Joined
Feb 2, 2003
I noticed after washing a lapped AX-7 HS it turns dark colored and not shiny at all. What kind of polish is good to make copper shiny and smooth and where can I get the polish?
 

zip22

Member
Joined
Nov 18, 2003
brasso, or generic metal polish. most say what metals they work well on.
 

Silversinksam

Moderator/ Silver Paste Taster©
Joined
Aug 8, 2001
Location
Sunshine State, USA
I like Bar Keepers Friend (Sold in Supermarkets for about $2) It's chemical free. Plus its been around since 1882 ;)

I hope your just cleaning the top and sides, because if you use any polish on the heatsinks base, the polish will kill your lapping hard work. It would be foolish to fill the microscopic pits and valleys with polish.


They claim you can get a free sample, but I cant see how, perhaps you need to e-mail them.

newsample.jpg


http://www.barkeepersfriend.com/products.htm

:( Edit, they stopped shipping free samples as they exhausted their supply of single use packets :(

http://www.barkeepersfriend.com/sample.html


Well, to make up for it, heres a free personalized pen

http://www.designsbylinda.com/guestbook.htm
 

clocker2

Member
Joined
Dec 5, 2003
Location
Mile High
What Sam said.

It's a common ( and potentially fatal in this case) error to confuse shiny with smooth and flat.
It would be a piece of cake to hit your HS with a buffing wheel and make it shiny, but if it's not flat and (relatively) scratch free then you've accomplished nothing.

If you were referring to the finned areas of the HS then that's a different story.
Copper stains/oxidizes very easily and the shape of the HS makes it very difficult to polish out, although it could probably be done.
A good cleaning in a ultasonic bath with the proper solution would be about the most painless method I can think of.
Most modern clock repair shops have exactly the setup required to do this, perhaps you could see if a local shop would be willing to clean yours for you.
That would get you as clean as possible.
Depending on the design of the HS, tumbling it would also achieve a very nice high polish, but I know that my Zalman wouldn't survive the process...the fins are way too thin and fragile.
 

L337 M33P

Member
Joined
Jun 5, 2003
Location
TEH INTERNETS
No polish is "good" to use on a finely lapped heatsink. It will most likely fill up the small valleys in the heatsink with oil if it is an oil or grease-based polishing compound, and if it isn't then you will most likely leave a fine coating of polishing granules in the cracks, preventing the thermal compound from doing it's job.

If the base is REALLY oxidised then consider lapping it again with a fine grit paper, if it has just gone slightly more coppery coloured then don't bother. The oxide layer is probably going to be less that 1 micron thick if it's just discoloured.
 
OP
Gremlin255

Gremlin255

Member
Joined
Feb 2, 2003
Im refering to the base of the HS. I have wet sanded the HS wit 600 grit sandpaper and washed it clean under the tap. After I noticed the base is discolored. Also i have read several lapping articles using polish to make the HS smoother and get a mirrored shine. Now I'm confused. Should I dry sand so it doesnt get discolored?
 

clocker2

Member
Joined
Dec 5, 2003
Location
Mile High
The discoloration that you see is irrelevant.
Your chip has no vanity and doesn't spend any time looking at it's reflection, so whether the base is a "mirror" shine or not won't matter one whit.
The slight staining that you see on a freshly sanded and washed copper surface are just chemicals in the water and shouldn't impact the HS's ability to conduct heat in the slightest.
 

Jawadali

Member
Joined
Jun 15, 2003
Check your temps before and after the lapping.

If the temps are lower, then the tarnish isn't interfering.

If the temps are higher, then you want to get rid of the tarnish.