Heater core -Al or Cu?

Aluminum or copper? I know copper is a better conductor of heat, and
hence high end computer processor heatsinks use copper, but is there any
real difference with automobile heater cores? Does one oxidize faster
than the other?

The price difference isn't enough to worry about... $27 vs $31.

"Jon C" > wrote in message
.. .
> Aluminum or copper? I know copper is a better conductor of heat, and
> hence high end computer processor heatsinks use copper, but is there any
> real difference with automobile heater cores? Does one oxidize faster
> than the other?
>
> The price difference isn't enough to worry about... $27 vs $31.

Depends.. Usually good quality copper will outperform aluminum.

Look at the chemical reactivity charts.. In general

Potassium High reactivity
Calcium
Magnesium
Aluminum
Zinc
Iron
Nickel
Tin
Lead
Hydrogen Breakover: Below this point, reaction with
hydrogen
, such as water or many
acids,generally doesnt happen


Copper
Mercury
Silver
Platinum
Gold
(from memory)
That means that aluminum is MUCH more chemically reactive than
copper. Doesn't have anything to do with heat conductivity of the
metal.

Now, corrosion inhibitor packages can offset some of the corrosive attack
And ****poor copper might not be a good buy.

But in general, copper is much better.

Jon C wrote:

> Aluminum or copper? I know copper is a better conductor of heat, and
> hence high end computer processor heatsinks use copper, but is there any
> real difference with automobile heater cores? Does one oxidize faster
> than the other?
>
> The price difference isn't enough to worry about... $27 vs $31.

Depends on the year of manufacture. Up into the 80s, most heater cores
were copper or copper alloys (brass) just like radiators were. Nowdays
most are copper with plastic end-tanks, just like most radiators are.

The corrosion characteristics are different, too. If this is a car that
uses DexCool antifreeze, do NOT put the copper heater core in unless you
want to fill the passenger floorboard with coolant after the DexCool
rots the copper. If it uses G-05 coolant or the traditional silicate
coolant, then either one should be fine.

Steve wrote:
> Jon C wrote:
>
>> Aluminum or copper? I know copper is a better conductor of heat, and
>> hence high end computer processor heatsinks use copper, but is there
>> any real difference with automobile heater cores? Does one oxidize
>> faster than the other?
>>
>> The price difference isn't enough to worry about... $27 vs $31.
>
> Depends on the year of manufacture. Up into the 80s, most heater cores
> were copper or copper alloys (brass) just like radiators were. Nowdays
> most are copper with plastic end-tanks, just like most radiators are.
>
> The corrosion characteristics are different, too. If this is a car that
> uses DexCool antifreeze, do NOT put the copper heater core in unless you
> want to fill the passenger floorboard with coolant after the DexCool
> rots the copper. If it uses G-05 coolant or the traditional silicate
> coolant, then either one should be fine.

It uses Dex-Cool.

Good to know. Thanks.

Steve wrote:
>
> Jon C wrote:
>
> > Aluminum or copper? I know copper is a better conductor of heat, and
> > hence high end computer processor heatsinks use copper, but is there any
> > real difference with automobile heater cores? Does one oxidize faster
> > than the other?
> >
> > The price difference isn't enough to worry about... $27 vs $31.
>
> Depends on the year of manufacture. Up into the 80s, most heater cores
> were copper or copper alloys (brass) just like radiators were. Nowdays
> most are copper with plastic end-tanks, just like most radiators are.
>
> The corrosion characteristics are different, too. If this is a car that
> uses DexCool antifreeze, do NOT put the copper heater core in unless you
> want to fill the passenger floorboard with coolant after the DexCool
> rots the copper. If it uses G-05 coolant or the traditional silicate
> coolant, then either one should be fine.

I have not seen any copper in an OEM (GM or Ford) radiator or heater in
at least 20 years. I have not seen all of them though.
Due to CAFE, copper was replaced with Al.
Also, I don't understand how copper would rot out because it is not a
base metal; i.e.: it's electromotive number is more positive than iron.
Cu is an electron donor, not an acceptor, unlike Al.
Aluminum -1.67
Iron -0.44
Copper +0.34

« Paul » wrote:
> Steve wrote:
>
>>Jon C wrote:
>>
>>
>>>Aluminum or copper? I know copper is a better conductor of heat, and
>>>hence high end computer processor heatsinks use copper, but is there any
>>>real difference with automobile heater cores? Does one oxidize faster
>>>than the other?
>>>
>>>The price difference isn't enough to worry about... $27 vs $31.
>>
>>Depends on the year of manufacture. Up into the 80s, most heater cores
>>were copper or copper alloys (brass) just like radiators were. Nowdays
>>most are copper with plastic end-tanks, just like most radiators are.
>>
>>The corrosion characteristics are different, too. If this is a car that
>>uses DexCool antifreeze, do NOT put the copper heater core in unless you
>>want to fill the passenger floorboard with coolant after the DexCool
>>rots the copper. If it uses G-05 coolant or the traditional silicate
>>coolant, then either one should be fine.
>
>
> I have not seen any copper in an OEM (GM or Ford) radiator or heater in
> at least 20 years. I have not seen


I think you're pretty much correct. Not much copper in ANY cooling
systems any longer.

> Also, I don't understand how copper would rot out because it is not a
> base metal; i.e.: it's electromotive number is more positive than iron.
> Cu is an electron donor, not an acceptor, unlike Al.
> Aluminum -1.67
> Iron -0.44
> Copper +0.34

I don't pretend to understand all the chemistry, but one of the biggest
problems with DexCool is that it
does not adequately protect copper-based alloys or the solders used in
them from corrosion.
One of the big reasons that Ford went with the G-05 inhibitor package is
because it does offer
protection to copper and solder that DexCool and other OAT inhibitor
packages don't.
Some water pump impellers are still brass/bronze alloy, and some head
gaskets are copper. DexCool
is well-known for not playing "nice" with those.

I guess when you throw a corrosion-control package into the equation,
the relative electron affinity
of different metals doesn't dominate which one corrodes and which
doesn't to the same extent
that it does in plain water.

Jon C wrote:
> Aluminum or copper? I know copper is a better conductor of heat, and
> hence high end computer processor heatsinks use copper, but is there any
> real difference with automobile heater cores? Does one oxidize faster
> than the other?
>
> The price difference isn't enough to worry about... $27 vs $31.

Weight. An aluminum radiator will be lighter than a copper one.
(In theory anyway... trying to compare apples to apples here is not
easily done, because the aluminum rad may be lighter, but which one can
transfer more heat? Which one is easier to repair? Which one handles
the abuse of racing better?)

based on the comments about dexcool, and the difficulty of changing most
heater cores, I'd be more concerned about lifespan than the .5 pound
weight difference or the $4 price difference.

Ray