Turbo-Jet

I installed shiny new rear calipers last winter, and now they are orange from a light layer of rust. :(

My question is it too late to paint them? Do I have to remove the rust (it is just a fine surface layer)? What paint is recommended (black)?

Thanks. :cheers:



[Modified by Turbo-Jet, 4:41 PM 8/22/2002]

Shark Racer

Steel wool the rust off, then paint black. Black has the best heat transfer... the brakes will cool off faster.

-Steve

Jughead

I painted mine with Red Devil Polyurethane "red". The calipers shouldn't get any where near as hot as the pads or rotor so hi-temp paint shouldn't matter.

I've had mine painted about a year & a half without problems. :chevy

69stingray

A buddy of mine uses "Engine Enamel" paint. He claims it is more durable and required for heat. Not sure if it is factual or not. :confused:

Twin_Turbo

You're kidding about that being the reason people should paint theirs black right? :)

Marck

Rogue Wave

I painted mine red using Rustoleum Professional paint I got from Home Depot. :)

Red paint disipates heat the fastest. I just had to say that. :lol: :lol: :D

norvalwilhelm

You do not need special heat paint. Even normal paint will survive on the engine block. I used the same paint that the car was painted in for the block and over years it has never burnt off.
As for the calipers you should remove as much loose rust as possible but the color is strickly what appeals to you.

MotorHead

First time I heard that in a long time, been trying to figure out why that is. Even in the electronics industry they say heatsinks painted black will work better but I don't know why.

I have never been given a good explanation to this, even in school, can someone here answer this question ?

Jughead

In the book "How to Hot Rod BB engines" they recommend painting the valve covers BLACK to help dissepate heat. No other details provided. I think I'm going to paint my BB-valve covers orange though. There's just something I like about the look of stock orange BB valve covers.

On a side note- I used the 500 deg Hi-temp paint on my block and then took a propane torch to it and the paint didn't flinch. It was un-marred. :eek: Just to be sure I then coated it with POR-15! :D

75 Hot One

In theory, black should get rid of heat quicker because darker colours have a higher emmisivity--meaning they radiate heat faster. In practice, conduction heat transfer may be the governing factor-due to all that air blowing over the calipers.

Kim72

My question is: what paint will, or will not, stand up to being slopped on, by brake fluid, during the yearly bleeding operation. Is one more durable than another??

Mystery Machine

O/T but...1970 Stingray, where did you get those wheels? What are they and how much? They look KILLER!!!! :cool: :cool:

Twin_Turbo

I've used Rusto-o-leum Hard Hat industrial quality paints. I've spilled brake fluid over it and it has held up just fine. Looks just like the day I painted it.

I'm not sure if you can buy the stuff in the US but I think you should. The aerosols are long silver colored. They have them in all kinds of cool metal colors like aluminium, stainless steel and so on. I thoroughly sandblasted my calipers w/ rough AlOx media so all the rust was gone (and alox acts sort of like a rust inhibitor) and then used primer before painting.

Marck

Turbo-Jet

Thanks. I want to paint them black, as that is the original color I think.

Having a black surface to aid in heat transfer is only effective when radiation (photons!) is the primary mode. In the case of a warm brake caliper, heat flux by convection is how the caliper is cooled. The local convection coefficient is a function of surface geometry and the thermal boundary layer. :crazy: I doubt the caliper actually gets that hot when compared to the rotor. In my last term of school, I designed and built a braking system for a lightweight racecar. I used aluminum rotors that were hard-anodized black. They worked well.

:cheers:

Turbo-Jet

Kim is this your car?

Jughead

Yeah, Yeah, that's what I meant to say! :lol: :lol:

Mystery machine---the wheels are polished aluminum American Racing Torque Thrust II's, 16x8 with 4 in backspacing.