Refurbishing rotors?

I've painted a few. Engine enamel should last quite a while.

 

I have used Wurth Zinc Spray after cleaning and masking the rotors. Usually a couple light coats...then I will apply a light coat of silver or gray paint over the zinc primer. I haven't been concerned with the outer edge, I just want the hubs free of rust.

 

Ever heard of anodizing.

Anodizing - Wikipedia, the free encyclopedia

 

Read a little further....." Ferrous metals are commonly anodized electrolytically in nitric acid, or by treatment with red fuming nitric acid, to form hard black ferric oxide. This oxide remains conformal even when plated on wire and the wire is bent."

Commonly done on race cars and aircraft parts.

 

Stop Rust with POR-15® - We Know What Permanent Means!

engine enamels, high temp cast iron paint or aluminium paint. very durable

 

Will they be able to powder coat the vains inside the rotor? If not that will still rust and get rusty water all over your wheels. Zinc coating coats the entire rotor, inside and out, and can be a DIY project; of course the swept area will always loose the coating and rust.

 

I have used the above process for years also but masking was always a pain. There was a thread a few weeks ago in the Technical Q&A section about a new Wurth product called "SBS Brake Treatment II" which has the same gray color and is suppose to last for approx. a year on a daily driver. The beauty of this stuff is it is designed to spray directly on to the rotor surface as well as the rest of the rotor. I got two cans but haven't had time to try it out yet. They have a video on the application of the product. Here is the original post: Wheel Hub Beautification Technique

 

My guess (and it IS just a guess) is that powder coat might not be able to withstand the heat from the outer edge of the rotor disc or vains. Powder coating the hubs should be fine, but I would double check with an expert about powder coating anything on the disc itself.

 

I read that thread, and watched the video when it was posted a while back. I dismissed it, as I don't think that is for me. I don't want to repeat the process every 9 to 12 months. I rather do in right one time, and be done with it...for several years at least.

I did my hubs on my daily driver BMW 5 years ago...they still look fine, no rust. I do think when painting hubs, it is worthwhile to use a smooth finish paint (gloss) as it appears to wash up better. A matte or rough finish holds the brake dust and dirt more, in my experience.

 

When I went through the brakes on the 308, I had a couple of used F-50, (355x32mm) rotors and a couple of new 360 322x28 mm rotors with custom hats.

Martin at Girodisc suggested that "we" turn the old fronts and have them "Zinc Washed" for durability, and also, so that they would be totally fresh and match the rears, which came zinc washed, (dipped in molten zinc).

Anodizing only works on aluminum, not steel or iron. I asked if Martin could anodize the e brake brackets I had made, but he said that the steel helicoil would f**K up the anodizing.


Here a couple of photos of the used and new rotors with custom hats. He said the zinc on the rotor face would wear off quickly and it did, but the vanes and perimeter still look light grey.

It might be good to see if martin could do a zinc wash after turning your current or new rotors.
As an item of interest, I just bought 4 new stock Porsche rotors that came "zinc coated", so I think the industry is moving in that direction.

While I had martin on the phone for another issue, I asked him if he had ever worked with "Black Chromating" zinc coated rotors and he said that he did and they did some thermal testing to see how much it added to the heat dissipation. He said it was worth about 2%, So, I gave up on that idea.

As to Powder Coating, I think it best to see what the individual vendor can do, as far as heat resistive paint.

I am thinking that ceramic coating might be too insulative, just what you don't want in a rotor.

There may be some proprietary heat dissipative coatings that also resist rust. This could be a win/win. I haven't really looked into this yet.

The local IPA is excellent.
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i have some aftermarket cross drilled rotors on my p car...
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i was going to take them off and soak them in evaporust. than spray the hub with some type of clear...

 

Years ago I cross drilled many many rotors. I was doing them for a Porsche dealer. They were selling them to customers at marked up prices. That was before they were easily available cross drilled on the aftermarket.

 

Definitely, give Martin a call. Even though he may not be able to do it for you, he is a very knowledgeable and helpful guy.

Good luck,
chris