Electroplating cpu air cooler. Good Idea?

[A_W_O_L__]

So as the title reads! I've got a build using fx 8350 that I'm thinking of really doing some custom stuff to including a custom paint job and a complete rework of the internals, the scheme is going to be kinda of a beat up junkyard look I never really felt that it was worth getting a custom water cool loop for it so I was instead thinking of putting a copper plating on the arctic freezer cpu cooler, now i already know there is no benefit performance wise (it's purely for looks) my main concern is that I've heard rumors that copper reacts to aluminium and I was afraid that if it started to get corrosion on the fins (like all pennies do and you can't buff between the fins ) that would hinder the cooling much, for the record I could care less if it did corrode as it would add to the character just don't want it running too hot. would love to hear your input!

 

[jacobweaver800]

So as the title reads! I've got a build using fx 8350 that I'm thinking of really doing some custom stuff to including a custom paint job and a complete rework of the internals, the scheme is going to be kinda of a beat up junkyard look I never really felt that it was worth getting a custom water cool loop for it so I was instead thinking of putting a copper plating on the arctic freezer cpu cooler, now i already know there is no benefit performance wise (it's purely for looks) my main concern is that I've heard rumors that copper reacts to aluminium and I was afraid that if it started to get corrosion on the fins (like all pennies do and you can't buff between the fins ) that would hinder the cooling much, for the record I could care less if it did corrode as it would add to the character just don't want it running too hot. would love to hear your input!

Yes, normally mixing metals will cause corrosion, sounds like a cool build your trying. Though if you can try not to mess with the heatsync itself too much.

 

[The Original Ralph]

electroplating is a bad idea unless there's some new material out there that increases the thermal conductivity of metals into the atmosphere

we or i work in an industry that use aluminum components to help transfer the heat out - for the heck of it, we tested anodizing the aluminum, basically not a plating but a chemical etching of the aluminum surface to prevent corrosion. Just anodizing the aluminum retarded the heat transfer rate as it was sealing the metal surface and serving to keep the heat from transfering

i'm pretty sure that's the reason most cooler's fins, the aluminum is a mill finish, no anodizing.

fwiw

 

[Karadjgne]

There have been full copper and copper plated heatsinks for years. Here's the gimmick. Copper plating won't change anything. Surface area remains the same, and even with the added thickness of the plating, copper is a better conductor of heat than aluminium.

The reason heatsinks are mill polished is turbulence. Anodized finss create too much obstruction to airflow over the surface, creating unnecessary turbulence between the fins, lowering flow. Basically acting like a slower moving fan than before, so temps raise.

I'd not worry about the differing metals, copper clad aluminium is just fine as long as it's not pierced and subjected to electricity, or electrolysis will occur. If that's happening to a heatsink, you have bigger issues.

I'd not worry about copper oxidation either. There's plenty of liquid silverware cleaners, a quick dunk, good rinse and a blow-dry and you are back, bright and shiny, with no need of buffing.

When you chrome plate aluminium, it's first plated with copper, then nickel, then chrome. Houses were once wired using copper clad (plated) aluminium. There's no issue with mixing metals unless subjected to electricity and oxygen, or if the plating is single sided.

 

[A_W_O_L__]

Well I figured at best i might loose a little performance but Id probably be doing very little overclocking (if any) I did a test running a half hour on a render and the hottest I could get it was 57c which should have been running 4.0ghz (stock speed) I was just worried that it could get terrible overtime, if it starts throttling the cpu with no overclock I would see that as a problem not worth having. I guess all this is in a perfect world tho, in reality there is probably going to be dust in the fins within weeks which would probably hinder more than any electroplating. I really appreciate all the input guys! its always nice to see it from different angles!

 

[The Original Ralph]

There have been full copper and copper plated heatsinks for years. Here's the gimmick. Copper plating won't change anything. Surface area remains the same, and even with the added thickness of the plating, copper is a better conductor of heat than aluminium.

The reason heatsinks are mill polished is turbulence. Anodized finss create too much obstruction to airflow over the surface, creating unnecessary turbulence between the fins, lowering flow. Basically acting like a slower moving fan than before, so temps raise.

I'd not worry about the differing metals, copper clad aluminium is just fine as long as it's not pierced and subjected to electricity, or electrolysis will occur. If that's happening to a heatsink, you have bigger issues.

I'd not worry about copper oxidation either. There's plenty of liquid silverware cleaners, a quick dunk, good rinse and a blow-dry and you are back, bright and shiny, with no need of buffing.

When you chrome plate aluminium, it's first plated with copper, then nickel, then chrome. Houses were once wired using copper clad (plated) aluminium. There's no issue with mixing metals unless subjected to electricity and oxygen, or if the plating is single sided.

i hadn't allowed for copper plating, but to be clear, anodizing SEALS the surface impeding the release or transfer of heat. The first 1/8" of air above a surface with air flowing above it is called the "boundary layer" and is actually very still relative to the stream of air flowing above it. When they test the airflow over an airplane wing, they tape small strips of cloth to the wing's surface, only attached at one end of the strip - when they turn the wind tunnel on, or videotape the wing in flight, you see very little movement of those witness strips

We actually found bead blasting the aluminum surfaces exposed to the airflow increased heat transfer

 

[Karadjgne]

Of course. Bead blasting increases surface area. On a flat plane, the surface is direct between any 2x points. Taken over a dimple from a bead blaster, the relative distance between 2x points is longer, accounting for the dip.

The distance between the fins on a heatsink is less than ⅛" though, yet the distance the flow has to travel to exit the back is still considerable. Any impedance creates turbulence, which will effectively hinder airflow.

For immediate testing, yes, you'll see lower temps, but once you climb above a certain threshold, that lack of airflow will pretty much lower TDP. The cooler will be more efficient at lower rpm, lower temps, but climb too high and that'll reverse.

It's like pouring water from a bottle. Start out shallow, slowly raising the bottle angle, the water flows faster up to a specific spot where it's optimum. Right after that, you get severely reduced flow, even with greater angle, greater affect of gravity etc etc, because the flow is impeded by back pressure, created vacuum etc. Size of the bottle neck doesn't even matter, still happens. Only time it doesn't is if it's a cup and the neck is the same size continuous, no impedance. With cpu coolers it's a fine balance to provide greater surface area, more fins, yet still provide sufficient flow according to the fan. It's why aio radiators with low fpi can work effectively with low SP fans, but you need a higher SP fan for high fpi rads. Overcome turbulence.

 

[jacobweaver800]

Of course. Bead blasting increases surface area. On a flat plane, the surface is direct between any 2x points. Taken over a dimple from a bead blaster, the relative distance between 2x points is longer, accounting for the dip.

The distance between the fins on a heatsink is less than ⅛" though, yet the distance the flow has to travel to exit the back is still considerable. Any impedance creates turbulence, which will effectively hinder airflow.

For immediate testing, yes, you'll see lower temps, but once you climb above a certain threshold, that lack of airflow will pretty much lower TDP. The cooler will be more efficient at lower rpm, lower temps, but climb too high and that'll reverse.

It's like pouring water from a bottle. Start out shallow, slowly raising the bottle angle, the water flows faster up to a specific spot where it's optimum. Right after that, you get severely reduced flow, even with greater angle, greater affect of gravity etc etc, because the flow is impeded by back pressure, created vacuum etc. Size of the bottle neck doesn't even matter, still happens. Only time it doesn't is if it's a cup and the neck is the same size continuous, no impedance. With cpu coolers it's a fine balance to provide greater surface area, more fins, yet still provide sufficient flow according to the fan. It's why aio radiators with low fpi can work effectively with low SP fans, but you need a higher SP fan for high fpi rads. Overcome turbulence.

You might be able to fix the problem by replacing the stock fan on the heatsync with a high static pressure fan, of course it wont completely fix the problem but in theory the threshold at witch the TDP the cooler can disperse starts to decrease will increase meaning the cooler can handle warmer temps than with the stock fan but eventually it will reverse like he said above.