How do you keep the edges and center of brake rotors clean?

356 Porsche-related discussions and questions.
Post Reply
Message
Author
Steve Douglas
356 Fan
Posts: 381
Joined: Wed Apr 02, 2008 9:49 pm
Location: Gilroy, CA

How do you keep the edges and center of brake rotors clean?

#1 Post by Steve Douglas » Sat Jun 23, 2018 12:13 am

I have started working on a 65 for the upcoming shows in Monterey this August, the owner wants the brake rotors to be clean on the outer edge as well as the center hub. The raw cast iron surfaces of the rotor rusts with a few days, wondering what will hold up being driven about 200 miles and will stop the bare metal from rusting. Also, how were the brake lines finished, one of the front looks like maybe copper coated steel? The others look like bare steel, maybe a cad plate?

Erik Thomas
356 Fan
Posts: 333
Joined: Thu Jan 14, 2010 4:55 pm
Location: Rhode Island

Re: How do you keep the edges and center of brake rotors cle

#2 Post by Erik Thomas » Sat Jun 23, 2018 3:28 pm

Steve:

Interesting question, however, have we reached the point where "professionals" take care of 356's and bring them out to contests where having clean brake rotors is more important that enjoying the drive there in a 356? "Pebble Beaching" a car, creating a trailer queen where nervous little folks compare brake rotor edges will only earn a special place in collector car hell.

I like to spray some cold galvanising spray on exhausts and brake rotors. This lasts a long time, and you can touch it up with a brush.

I have been using brake lines made up out of a Conifer alloy. These are high performance copper nickel 90-10 These do not rust. Porsche now uses this material OEM. Originally, the steel brake lines on a 356 had a light coating of zinc plating, or may have been plain steel painted black. I am not sure how to finish these for 100% authentic appearance.

Steve Douglas
356 Fan
Posts: 381
Joined: Wed Apr 02, 2008 9:49 pm
Location: Gilroy, CA

Re: How do you keep the edges and center of brake rotors cle

#3 Post by Steve Douglas » Sat Jun 23, 2018 4:53 pm

This an interesting case, Christopher bought the car with 5800 miles on it in 1970. He lived in surfer shack and stored the car in his parents garage, only taking it out when it as sunny and warm. A professional student, living on a family trust fund while he is in school. Over educated and not really aware of the real world, 19 years ago he decided he wanted to restore the car, it wasn't rusty, never been hit, but he felt that it was inferior, so he took everything he could off the car and started refurbishing the parts. He is very "anal" about everything, moved to his "hermit cabin" in the Santa Cruz Mountains, he built a climate controlled garage just for the 356 and it's parts. About 8 years ago I helped him assemble the front end, 15 years ago helped put in a new wire harness, even though the old one was in good shape but the insulation was faded and a bit stiff. Now the transaxle is in, the engine is tested and ready to go in, so all that is left is the brakes. That is where he is at now. He needs in his mind to be able to drive the car to Monterey and still have everything look like it does now, I keep telling him that it won't matter if there is a bit of rust on bare steel parts, or the exhaust is discolored. He worried about the seat springs and wires rusting, as well as the under dash that was not well painted, they are both done to perfection.
So we decided to use POR15 on the brake lines, leaving the steel tube nuts clear coated steel. We will try the spray galvanizing, LPS brand in bright finish, it will look good and will hold up under the heat. Erik, Thanks for the idea. Although it is hard to see it when the wheels are installed.
Steve

User avatar
Bruce Hagopian
356 Fan
Posts: 98
Joined: Sun Dec 21, 2008 8:13 pm
Location: Fresno, CA

Re: How do you keep the edges and center of brake rotors cle

#4 Post by Bruce Hagopian » Sat Jun 23, 2018 6:56 pm

Spell checker strikes again? The copper nickel alloy brake lines are called cunifer, conifer being an evergreen tree.
Bruce Hagopian

Ivan Fuller
356 Fan
Posts: 111
Joined: Thu Aug 06, 2009 3:52 am
Contact:

Re: How do you keep the edges and center of brake rotors cle

#5 Post by Ivan Fuller » Sat Jun 23, 2018 7:34 pm

Ceramic coat then reface the disc. Will look good for years with no rust. There is a color that resembles bare metal.
Its not a cheap option.
(My 65 911 appears to have residue that looks like the gray exhaust color?)
'58 Speedster
'65 911
revivem.co.nz

ray nelson
356 Fan
Posts: 222
Joined: Thu Sep 16, 2010 12:32 pm
Location: Boca Raton, FL

Re: How do you keep the edges and center of brake rotors cle

#6 Post by ray nelson » Sun Jun 24, 2018 8:05 am

BMW motorcycles put a light zinc plating on their cast iron motorcycle rotors to keep them from rusting. Of course the plating would be worn off quickly where the pads contacted the disc but the rest of the rotor still looked good. An important consideration in an application that has the rotor (disc) in full view.
Otherwise, cost no object, have one off stainless steel rotors made.

Erik Thomas
356 Fan
Posts: 333
Joined: Thu Jan 14, 2010 4:55 pm
Location: Rhode Island

Re: How do you keep the edges and center of brake rotors cle

#7 Post by Erik Thomas » Mon Jun 25, 2018 3:56 pm

This thread got me to thinking about the daily driver cars. Here in Rhode Island I continually replace brake rotors, usually in the spring because the discs rust badly during the winter months. Would seem simple enough to turn up some stainless rotors. They make them for airplanes, I have a set on my Cessna. This would not work for the ventilated type, which would have to be machined from a casting.

User avatar
Wes Bender
356 Fan
Posts: 2217
Joined: Wed Aug 27, 2008 10:54 am
Location: Alpine AZ, Green Valley AZ

Re: How do you keep the edges and center of brake rotors cle

#8 Post by Wes Bender » Mon Jun 25, 2018 9:36 pm

Sounds like a good idea, Erik, but your Cessna doesn't get the number of brake applications that our 356s do in regular use. SS is usually pretty soft. You might have to replace them more often.
Some days it just isn’t worth the hassle of chewing through the restraints......

Martin Benade
356 Fan
Posts: 3526
Joined: Wed Nov 23, 2011 10:52 am
Location: Cleveland, Ohio

Re: How do you keep the edges and center of brake rotors cle

#9 Post by Martin Benade » Mon Jun 25, 2018 11:11 pm

I didn't think the friction characteristics of SS were that great for brakes, I am surprised they are good for a Cessna. They looked good and worked poorly on my Honda 400SS motorcycle.

ray nelson
356 Fan
Posts: 222
Joined: Thu Sep 16, 2010 12:32 pm
Location: Boca Raton, FL

Re: How do you keep the edges and center of brake rotors cle

#10 Post by ray nelson » Tue Jun 26, 2018 8:42 am

Most modern motorcycles use some alloy of stainless steel rotors and they seem to work very good but cast iron is a better choice for friction characteristics. Cast iron rotors are also marginally heavier than SS (maybe because SS can be thinner?)
Of course if the vehicle is kept in a garage and seldom driven, high temperature paint would probably work, just don't paint the areas that the pads contact.
Also driving through salted slush will pretty much destroy the whole car as well as the rotors :shock:

Post Reply