rotors getting rusty and corroded

[jokken]

I got a set or drilled and slotted rotors and after a short time the holes and slots were rusted and corroded and filling in with brake dust. The same thing happens to the areas between the front and back surface of the rotor.

I was wondering if it might be a good idea to paint all these areas. I was thinking of black high temperature engine paint. what ever overspray would be rubbed off when braking for the first time.

I am guessing this would probably limit the functionality of the holes and slots and act like a insulator causing the rotor to stay hot. but then again maybe not, if the hi temp paint transfers heat correctly maybe it would act more like a heat dissipater causing negligible difference in temperature


thoughts, ideas?

 

[Jim Henderson]

I am not a brake expert...

Rotors can get really hot. I think you might need a paint more suited to headers. Engine paint is OK but only for a few hundred degrees if I recall. Header paint will handle over 1,000, but it is thin and if I recall flat in color. Even so I kind of doubt that the paint will last.

Rust is a fact of life on brake components due to the tremendous heat cycling and water etc.

From what I have read the holes are really meant to act as a vent for the hot gases that boil off the pads as they are applied. They also help a bit with cooling due to movement. I doubt paint in these areas would hurt much. The rotor itself is a giant heat dissipator, the slots don't dissipate a lot of heat other than by moving thru the air.

Don't do like that ditz several years back did. There was an interesting web posting I think for VW Rabbits where the bozo painted everything on the brake system and was quite proud of it too. Included rotor surfaces, pads, calipers etc. It was beautiful.

Interesting that the slots are filling in with brake dust. I had assumed that with air movement, the dust would be blown out.

Good Luck,

Jim Henderson

 

[jokken]

bump,

any other opinions on this?

 

[Jim Henderson]

Read a post on the Ford Trucks website with similar issues as yours http://www.ford-trucks.com/forums/521109-warped-or-rusted-rotors.html. They didn't discuss paint, but did mention that for cast iron rotors, rust is a fact of life and that driving too little can make it worse. The Rust gets "burned out" if you drive it enough to get the brakes hot. Sitting allows the rust to grow and makes hot spots which cause rotor warping and more rust etc.

The solution appears to be plated rotors. In this case Cadmium. I have read about other plated rotors on a chebby website, forget what kind of plating. But the plating prevents rust in non contact areas. The pad areas scrape the plating off after awhile but then the pads keep the rotors clean. They got deep into discussion there, try looking for NAISSO tech articles

You might look into plated rotors. Probably expensive but should work.

Hope someone with experience in painting rotors talks up.

Good Luck,

Jim Henderson

 

[Frat-man-du]

Powdercoat.

Be care to specifiy which areas are to be coated.

I did this on one of my '65 T-birds over 15 years ago and they are still silver. Granted It has had only 10K since then, but they do get stupid hot! Cost was only $20 each.

 

[5.7sbc]

I think you are looking for zinc-plated right? I wouldn't paint rotors just doesn't seem like a good move. Rotors are gonna rust no matter what. Expose metal to oxygen long enough and it'll rust add a little water and it'll rot given a long enough time. Rotors are exposed to both of these so it really is only a matter of time.