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Discussion Starter · #1 ·
Has anybody had this issue early on and if so, then how to address...

I've had my ride for three days now. Absolutely love it, but also noticed some small rust spots already on the discs. Not sure how to get rid of them.
 

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I get this on both of my cars. Oxidation which rubs off when you use it, think the only way you can avoid if you keep it outside is a car cover. Mine stops it on 90% of the disk as the cover doesn't 100% cover the tire.
 

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Just on the rotor surface or elsewhere as well? A picture would be helpful.
 

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It's just on the surface. Was thinking of getting an air compressor to blow the air off of the surfaces once I'm parked, and in each cross-drilled hole. That's ok to do at home, but not realistic to do that every time I drive anywhere to park. I'll probably start to use the car cover when I'm parked outside during the day. It is garaged at night.
 

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Yup....happens to all my cars that are left outside without having been driven for awhile.
 
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Usually from humidity, no? Kind of hard to avoid, and probably not worth worrying about unless planning to show or photograph the car.
 

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worry not...

Has anybody had this issue early on and if so, then how to address...

I've had my ride for three days now. Absolutely love it, but also noticed some small rust spots already on the discs. Not sure how to get rid of them.
... happens after carwash, too. Drive and then brake... presto, viola, gone. :laugh:

Enjoy the ride amici,
 
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You will never be able to prevent rust from forming on the brake disks unless the car is garaged with AC. A car cover will not do anything to prevent it. You have to get rid of the moisture in the air and that's only done with an AC or a dehumidifier as the main culprit is moisture in the air. Same principle as storing your bicycles indoors to prevent the chain from rusting. Dont worry about the surface rust as the first time you press your brakes, its removed by the pads.
 

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You will never be able to prevent rust from forming on the brake disks unless the car is garaged with AC. A car cover will not do anything to prevent it. You have to get rid of the moisture in the air and that's only done with an AC or a dehumidifier as the main culprit is moisture in the air. Same principle as storing your bicycles indoors to prevent the chain from rusting. Dont worry about the surface rust as the first time you press your brakes, its removed by the pads.
Did with my cover, left it for 16 days outside covered and 3/4 the rotor was pristine and the bottom (poking out of the cover) was rust. Looked quite funny. I'm checking the brake pads tonight after it's been sitting for 6 days - will take a pic if it's done the same :)
 

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Usually from humidity, no? Kind of hard to avoid, and probably not worth worrying about unless planning to show or photograph the car.
O.P. is in Fresno and it is summer. There is no humidity.

If the car is outside, maybe the automatic sprinklers are getting it wet at night?
Or maybe the neighbor's dog...
 

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It may slow it down but it will not prevent oxidation unless you remove the moisture in the air. Also, the time frame when you start seeing oxidation depends on the climate where you live, humidity levels and elevation. You probably seldom see rust forming on rotors living in Baghdad but if you live in Miami, Florida, on any given humid night, you will see oxidation forming within 6 hours. All this is of course not applicable to ceramic rotors.
 

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23% isn't no humidity. How much is too little for rust spot formation?

http://www.intellicast.com/local/weather.aspx?location=USCA0406
I trust these guys more, 19%

http://forecast.weather.gov/MapClick.php?lon=-119.81031337890624&lat=36.74024873447756#.WcA7Q820lhE

But the critical point is the dewpoint compared to the overnight low.

Fresno dewpoint: 39F
Fresno overnight low forecast: 59F

Compare with

Houston dewpoint: 76F
Houston overnight low forecast: 77F

Surfaces exposed to the night sky will drop below the air temperature, so everything gets wet in Houston overnight, but nothing gets wet (unless the irrigation sprinklers got it, or it is artificially cooled) overnight in Fresno.

In the high desert the situation is dryer:
(from today's prediction at my house)
Dewpoint: 25F
Overnight low: 40F

Note that the dewpoint is below freezing (it almost always is below freezing in the high desert), so liquid water dew does not form. Exposed surfaces at night can fall far below the air temperature (I have observed a 10F difference), but I don't think 15F is likely. The dryer it is, the greater the difference can be between air and surfaces at night (water vapor is a potent greenhouse gas). I expect that ice/frost is less aggressive at forming rust on exposed cast iron than water.
 

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Automotive tire Motor vehicle Hood Automotive lighting Vehicle
These are the rotors of my 2018 QV, it’s been in winter storage for the last 4 months indoors and no rust.
Tire Wheel Automotive tire Vehicle Motor vehicle
Automotive tire Motor vehicle Hood Automotive lighting Vehicle
Tire Wheel Automotive tire Vehicle Motor vehicle
Tire Wheel Automotive tire Vehicle Motor vehicle
 
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