Technical discourse is so much more satisfying than wrangling over spam...
Gary McCormick
San Jose, CA
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Paul wrote:
> Okay, here is my 2 cents, backed by a few years of air conditioning and
> heating schools and work.
>
> Yes, paint will slow down the heat transfer!
Defend your thesis, Paul (Tell us why paint slows down heat transfer ...)
> Will it matter on your rear
> drums? Probably not unless you race.
I agree...
>
> Flat black can aid in transferring
...radiating
> heat more so than a gloss light or
> white if you need to paint something. The advantage comes in the additional
> surface area,
and the color...
> an advantage not found when painting rough cast brake drums.
> They offer plenty of surface area to begin with.
probably true above the microscopic level...
> Also remember heat
> transfer works both ways; a car painted flat black would get extremely hot
> if left in the sun to absorb heat.
...and would cool down faster after the sun goes down. Absorption and radiation
are two
sides of the same coin.
Check out the roof, hood or trunk of a light-colored and a dark-colored car
parked in the
same surroundings on a chilly, clear night (this experiment may not be possible
in the
Northwest US and BC). If conditions are just right (temperature, humidity,
etc.) you will
see evidence of a higher rate of radiation cooling on the darker car -
condensation, or
frost if it is chilly enough.
This is generally not a concern with your brake drums (or your radiator, for
that matter).
Very few cars are built such that the brake drums or the radiator or exposed to
a lot of
sunlight...
> And since this is a roadster list, I can
> safely assume that all of us, with the possible exception of those in
> Seattle <grin>, know how warn a black seat can get when the top is left
> down!
Carry one of those lightweight cotton car covers - it takes 30 seconds to
unroll it and
cover the car, only a little more than that to roll it back up and stow it on
the package
tray behind the seats. No more hot seats (or bird crap in the interior)...
>
> So what did I do? I used a rust bonding agent ( similar to POR15 but
> cheaper ).
OK on a 1600 - not going to help on a 2000 (drums are aluminum...), but my
question is -
what does this do for you? Your drums are not going to rust away to nothing...
oh wait, I
forgot - you're in Ohio.
> If you are running open aftermarket wheels, paint your drums any
> color you want.
Just please, please - not fluorescent orange! (Don't laugh, I've seen it - but
not on a
Roadster, thank goodness...)
> It won't make that much difference in even 'spirited'
> street driving. But I would recommend a high temperature paint.
>
> Paul
> OROC
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