I live in Boston, where I need to worry about rusting things. I need to replace the worn front brake rotors. I see some companies making electrocoated brake rotors, where the center part (where brake pads don’t touch) is coated/painted with black stuff. Oh, the car is 2006 Ford Focus ZX4 SES.
My questions are:
Does that eleminate (or at least significantly reduce) rust?
Does the paint/coating withstand the rubbing or prolonged contact with the wheel, so that the wheel would not stick/rust to the rotor?
The price for the regular rotors is about $28/rotor, while the e-coated rotors are about $38/rotor. So, I would be spending about $20 more per set.
Does that seem worth it?
Don’t worry about the rust on that part of the rotors.
Get a small tube of anti-seize and apply it lightly to the face of the hub where the wheel mates up.
That will keep it from sticking.
Well when you take a setup like the one on my Dakota, were the bracket and everything is basically replaced,yes powdercoating helps.When my calipers failed all that bare metal stuff was rusted almost beyond function,so really it probaly is worth it(looks good too)
But I just noticed you were specifically referring to the rotors,themselves,no that doesnt make much difference,the rotors are basically a consumable part anyway(make sure you use ceramic,rotor friendly pads.
Related topic… I live in Boston also, and I am a very conservative driver. As a result, my rotors can rust through before the pads go. I remember recently having my brakes checked, and the mechanic said he could see through the rotors.
Which leads to my question, why are they not made of stainless or some other rust resistance alloy? Can I buy such?
I think brake rotors cannot be stainless steel, because stainless cannot dissipate heat efficiently. On the other hand, it cannot be copper/brass or aluminium, because they are too soft.
if you can keep ceramic rotors cool via special channels, then stainless could do the same. The thermal conductivity of SS is low, true, but not as low as ceramic.
thermal conductivity of Steel is 46 W/mK
thermal conductivity of Stainless Steel is 16 W/mK
I think I’m not the only one whose rotors wear more due to rust than abrasion. If you don’t use your car for a few days, the rotors develop a coating of rust. this wears off quickly, but it takes some of the rotor steel with it. Possible that a large percentage of normal rotor wear (at least in the rust belt) is due to rust.
Stainless steel is not a good canidate for brake rotors not only because of its lack of conductivity but also because. if you get it hot enough, it is no longer stainless so you are left with a low conductivity rotor that rusts.