Copper oxidation on heatsinks

[Cookie Monster]

How do you get rid of them on your copper heatsinks? Any recommendations?

edit - OXIDATION! *slaps forehead

 

[Tim]

I sanded them off once. I'm sure there's a better method.

 

[aigomorla]

buff with ketchup.

And im being serious.

 

[Zepper]

C'mon aigo - gotta tell it ALL. Is Heinz or Hunt's best?.. Hmmm, I'd think that Copper + Acid + O2 = corrosion... I'll need to be convinced of the science behind this one.

Caig Labs Deoxit does a decent job on corrosion. Search in the Hot Deals section on- Caig -you'll find a thread on a kit that includes several small containers of their products. Or go to fleaBay and search on Caig or Deoxit - you'll find it that way too as well as large cans of just Deoxit 5% at better prices than you can get elsewhere. As always, make sure you are getting a deal as the prices on McMaster-Carr exceed the prices on Caig's own web site for some items. So caveat emptor.

Caig will clean surface corrosion and retard further corrosion, but won't reverse all the discoloration. I'm a bit leery of aigo's suggestion, but perhaps Tarn-X could reverse coloration. You'll have to check the Tarn-X instructions to see if it's safe for copper - works well on silver.

If the corrosion has pitted the CPU/HS interface surface, I would probably lap it.

.bh.

 

[RallyMaster]

Now is it corrosion or oxidation?? Or are we just referring to the same thing here?

 

[Rubycon]

Catsup polish :laugh:

Best leave it alone. The best way to preserve metal (appearance only) is a lacquer type coating no different than used on brass beds.

Caig is good for switches/sliders/electrical contacts.

 

[aigomorla]

Originally posted by: RallyMaster
Now is it corrosion or oxidation?? Or are we just referring to the same thing here?

lol... i was assuming oxidation.



Whats wrong with ketchup, you can also use tabasco hot sause, but that might iritate your skin. i use it to make my water blocks all shiny again on the base. Of course i wipe clean with iso.

Its basically the vinegar. And it works well at making my blocks back shiny.

 

[Rubycon]

Use brasso to polish everything EXCEPT the bottom of the heatsink! Any kind of polish is bad for the bottom as it will not allow the TIM agents to do their job and you wind up with a blow out.

 

[Zepper]

Yup, I was gonna say that Brasso was an option as what discolors brass is mainly the copper in it. There is something out there for polishing and reversing coloration on copper pots (like Revereware) too. Hope you have enough ideas.

.bh.

 

[Cookie Monster]

Bleh was never good at chemistry.

I meant oxidation. Better change the thread title! When i was cleaning the zalman 7000 ZS it seems that it had started to oxidize in some places (some on the base of the heatsink). Should i ignore it or "clean" it away (lack of a better term).

edit - id take heinz

 

[Zepper]

If it is just discoloration, it shouldn't affect the performance significantly. I'd hesitate to put anything like Deoxit on the contact surface, but it will prevent further discoloration. The active ingredient binds with the metal. I suppose if you wipe the carrier and any excess off well with alcohol, it shouldn't have much real effect on performance either. I used it on an aluminum HS once and noticed little diff.

.bh.

 

[BonzaiDuck]

A Poppa Tomato, a Momma Tomato, and a Baby Tomato were walking down the street.

Pretty soon, the Baby Tomato began to lag behind.

So the Poppa Tomato walked back, took a flying leap, and jumped on the Baby Tomato, splattering the latter all over the pavement.

And the Poppa Tomato said:

"Ketchup!!"

 

[MadScientist]

Aigomorla is on the right track. You can also use taco sauce. It's the combo of salt and vinegar (acetic acid) that cleans copper. For best results make a paste of vinegar, salt, and flour. Acetic acid is a weak acid and vinegar by itself will not do a very good job cleaning copper. Salt (sodium chloride), combines with acetic acid from the vinegar to produce sodium acetate and hydrogen chloride. Hydrogen chloride is a strong acid and the combination of it and sodium acetate rapidly cleans the copper.
Make sure after you clean your HS that you wash it with hot water followed with 91% isopropyl alcohol.

A combo of lemon juice (citric acid) and baking soda also works.

I have seen it mentioned here a number of times not to use Brasso to polish the bottom of your HS or IHS after lapping. I don't use it because I stop at 800 grit when lapping (another subject that's been discussed), but some people use it as a finishing step to get that "mirror" finish. Brasso is not actually a polish in the sense of say a car polish. It does not contain any waxes. Brasso MSDS. It contains petroleum distillates (paint thinners), crystalline silica, kaolin (clay), oleic acid, and ammonia (ammonium hydroxide). No waxes. It's the combination of silica, oleic acid, and ammonia that gives you that mirror finish.
I see no problem in using Brasso on the bottom of your HS, if you do a thorough job of cleaning it off the HS with mineral spirits (also called Stoddard solvent or paint thinner), followed with 91% isopropyl alcohol.

 

[uclaLabrat]

Just use vinegar. The above mentioned won't be terribly effective. The acetic acid hydrolyzes the copper oxide and washes away the Cu2+ ions, leaving copper metal underneath. But copper metal reacts with oxygen to form more copper oxide, so your best bet to clean the surface is wash with vinegar, rub with rubbing alcohol, dry quickly with lint-free towel, and add TIM and install heat sink to minimize exposure to O2 and thus re-oxidation.

 

[MadScientist]

Adding salt to the vinegar increases the ionic strength of the weak acetic acid (~5%) solution and speeds up the removal of the copper oxides (tarnish).

You can use this as your kid's next science fair project. The Cleaning Power of Taco Sauce

Another taco sauce experiment

 

[aigomorla]

Originally posted by: MadScientist
Adding salt to the vinegar increases the ionic strength of the weak acetic acid (~5%) solution and speeds up the removal of the copper oxides (tarnish).

You can use this as your kid's next science fair project. The Cleaning Power of Taco Sauce

Another taco sauce experiment

thanks for the great link.



yeah as i said ive been using ketchup all this time. :T

Umm.. its heinz to be exact. :T

 

[Cookie Monster]

Thanks for the input guys!