Sound technical content, curated with aloha by
Ted Mooney, P.E. RET
Pine Beach, NJ

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Finishing and plating of CPU / GPU Water Blocks

Q. I have a copper heatsink that is cooled with distilled water and Wetter Water which runs through an aluminum radiator. I am worried that the copper will destroy the aluminum. I was wondering if my troubles would disappear if I plated the aluminum radiator with copper? Does anyone know how to do this ?

Sal Fortuna
- Malabar, Florida
2002

Water Block

A. Try pure ethylene glycol instead of water and you will totally avoid corrosion problems.

John Tuohy
- Ireland
2002

ACRONYMS:

CPU = Central Processing Unit
GPU = Graphics Processing Unit

A. Sal, your problems might disappear for a time by copper plating the aluminum (there are many companies that can do that I don't know if around your area, but in the US yes). If you have internal passages you will need electroless copper. The problem is if the copper gets perforated your problem will become an immediate and sure failure.

Guillermo Marrufo
Monterrey, NL, Mexico
2002

Multiple threads merged: please forgive chronology errors :-)

Avoiding corrosion with copper water block and aluminum radiator

Q. I have a hollow copper block that is used to cool a CPU chip. The copper block is cooled by distilled water. The water is cooled by an aluminum radiator. Is there anything I can do to protect the aluminum radiator from corroding ? Thanks !

Sal Fortuna
- Malabar, Florida
2002

A. Hi Sal. Well, the easy traditional solution was to use a chromate based inhibitor in the circulating water. But for environmental reasons, that's something you don't want to do anymore. Can you not just use automobile antifreeze (ethylene glycol plus corrosion-resistant additives) instead of distilled water? Good luck.

Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2002

A. Sal, in order to prevent corrosion problems, you must isolate the aluminum from the copper and prevent any copper from becoming soluble in the cooling water. If you system is typical of most cooling systems, there is likely to be rubber or another non conductive material connecting the aluminum heat exchanger to the copper parts. This prevents the formation of a galvanic corrosion cell. To prevent the copper from becoming soluble in the cooling water, you should add a corrosion inhibitor to the cooling water. Please contact me directly for more details on corrosion inhibitors. If you have already operated the system without an inhibitor, you may have immersion plated some copper on the aluminum which will greatly accelerate the corrosion of the aluminum. If this is the case, the aluminum heat exchange should be isolated and cleaned to remove the copper.

Roy Nuss
Trevose, Pennsylvania, USA
2002

Q. Okay guys this might be long but here goes. I am overclocking my PC. To cool this extra heat off my processor I am going to use a water chiller I am making on my own. Problem: The water block on my processor is solid copper. The water reservoir is made out of aluminum. The problem comes in with galvanic corrosion (I believe it is called). You get an electrolysis effect, I believe, that corrodes your metals. Very bad. I had someone tell me (I should have thought of this on my own) that run some silver nitrate through your water block and it coats the copper. Should this work at protecting the copper? Will the few atom thickness of the silver be enough to protect it and stop the reaction?

Brendan Zoglman
computer consulting - Milwaukee, Wisconsin
2004

A. Hi Brendan. The aluminum should not touch the copper; hoses should be plastic. Then true galvanic corrosion cannot occur. Commercial antifreeze includes corrosion fighters that will help.

Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2004

Lapping and Polishing Copper Water Block

"Hardware Hacking"

on AbeBooks

or Amazon

(affil links)

Q. Hi, I am currently lapping and polishing copper water block and heatsinks by hand. I am trying to find a lapping machine to do the work to save me a lot of time. My needs are small but none of the companies I have contacted have been able to give me any help as to the lapping plate I would need to use nor the lapping compounds or grit sizes to use with copper can anyone give me some advice.

Thomas Walters
hobbyist - Plymouth, Pennsylvania, USA
2005

A. The lapping process is removing the thickness by rubbing it to achieve desire flatness; a few companies do have small scale machine like, Fujikoshi Machineries, HAMAI, & Peter Wolters.

Regards,

CHONG [last name deleted for privacy by Editor]
- Malaysia
2005

Nickel Plating GPU Water Block

Q. I need to nickel plate a copper GPU water block and didn't know if there was a service in town that could do it for me or, if not, what all I need to do it myself?

Mac Wheeler
- Memphis, Tennessee USA
June 11, 2015

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