gettng rid of rotor heat?

[chrismorse]

Hi Guys,

I'm redoing the suspension and brakes on my dad's 911. The front calipers are out and apart and i've purchased Caswell's electroplating kit and i am thinking about a black chromate coating over the new zimmerman zinc coated rotors and possibly the calipers too.

Is this likely to help or am i better off going with high heat black stove paint to help get rid of the heat???

I know we are talking about a relatively small amount of additional heat rejection, but i am looking to do the best i can, cuz i like brakes.

thanks,
chris

[911s55]

As far as high heat coatings, they aren't designed to inhibit heat build up or dissipate it they are designed to try to withstand the heat and not let the finish fail. I think they will hold the heat in if anything. The way to cool your brakes is with venting and air flow. Some experts should arrive shortly.

David

[Flieger]

You can use a coating on the bell area but I would just leave them alone.

[ShakinJoe]

Black WILL discipate more heat, but just a small amount.

[chrismorse]

The plan is to duct air to the eye of the rotor but also clean up and paint the rebushed suspension and cad plate the calipers.

If i can slow down the corrosion/rusting of the disc and slightly improve the heat rejection, I'd like to do that.

thanks,
chris

[KTL]

Originally Posted by chrismorse

or am i better off going with high heat black stove paint to help get rid of the heat???

If you're talking about flat black BBQ grill type spray paint, don't bother. Brake parts cleaner removes that paint VERY easily.

I painted a handful of engine parts (sheetmetal, engine support console and some other misc stuff) and was unpleasantly surprised when I wiped off my sheetmetal with a rag sprayed with brake cleaner, to clean up some oil I spilled. Red shop rag was black as night after only a few wipes!

[Fleming]

The caswell plating process will hold the rust at bay as you intend. Good idea.

I'm noticing some of the rotor manufacture are now using the E coating on the hub and outside edges of the rotor to keep them looking better for the initial run in.

I'm not sure what your break-in period - the cad plating wear thru will be. Depending on how aggressive your brake pads are (race pads, street pads, metal/carbon content?) it may take a day or two to be back at raw metal in the pad area. Do you have access to a rotor lathe to remove the plating on the brake pad contact?

The remaining rotor and caliper will look better for a short time.
The heat cycling and brake dust will leave them sooty black in no time at all.

If you will be doing track duty (or you drive down mountain curves daily) Yes get air into the center and both sides of the rotor for maximum cooling.

[chrismorse]

I have posted a couple of inquiries on the caswell forum re: heat dissipation and appropriateness for a rotor wear surface, or the need to turn the freshly plated rotor.

My guess is that rusty scale is a fair amount worse heat transfer medium than a painted or plated surface. Curious to know the difference.

chris

[chrismorse]

Originally Posted by Fleming

The caswell plating process will hold the rust at bay as you intend. Good idea.

I'm noticing some of the rotor manufacture are now using the E coating on the hub and outside edges of the rotor to keep them looking better for the initial run in.

I'm not sure what your break-in period - the cad plating wear thru will be. Depending on how aggressive your brake pads are (race pads, street pads, metal/carbon content?) it may take a day or two to be back at raw metal in the pad area. Do you have access to a rotor lathe to remove the plating on the brake pad contact?

The remaining rotor and caliper will look better for a short time.
The heat cycling and brake dust will leave them sooty black in no time at all.

If you will be doing track duty (or you drive down mountain curves daily) Yes get air into the center and both sides of the rotor for maximum cooling.

I saved the old pads and will use them to burn through the zinc and black chromate finish. I thought about just having the new rotors turned to both provide a clean new face finish but to eliminate any, (or as much as possible) runout; but remembered that the "M" caliper uses a smaller pad than the S, so a band of exposed iron would immediately start to rust.

More important than the hub area and outter edge is the interior of the rotor air passages. There is a huge amount of surface area there that i would like to keep from rusting and even a 10-15%, (wild ass guess) increase in heat rejection would be a nice help.

chris

[911pcars]

You can apply ceramic coating to the exposed, non-friction areas for corrosion protection. However, if you want to radiate heat rather than retain it, a thermal dispersion-type coating would be more appropriate here. However, this product/application could be costly.

As with most paint jobs, proper prep is important. Media blast to clean metal, degrease, then paint.

I'd just spray paint the hub, edge and vanes, then take it easy on the brake cleaner. Retouch periodically if necessary.

Sherwood

[KTL]

This stuff works FANTASTIC on brake rotor OD/vanes and hubs, mufflers.

COLD GALVANIZE Corrosion Inhibitor, Rust Inhibitor: LPS Labs

[HawgRyder]

Several motorcycle makers ...Harley for one...makes a heat dissapating paint for cylinders.
It is very thin...and goes on in several coats to cover...with heating in between coats.
It seeps right into the pores of the metal...and sheds heat like a charm.
Any other type of paint will seal the surface...not allowing heat to get out.
Bob

[911pcars]

Originally Posted by KTL

This stuff works FANTASTIC on brake rotor OD/vanes and hubs, mufflers.

COLD GALVANIZE Corrosion Inhibitor, Rust Inhibitor: LPS Labs

That product is good too.

[911pcars]

Originally Posted by HawgRyder

Several motorcycle makers ...Harley for one...makes a heat dissapating paint for cylinders.
It is very thin...and goes on in several coats to cover...with heating in between coats.
It seeps right into the pores of the metal...and sheds heat like a charm.
Any other type of paint will seal the surface...not allowing heat to get out.
Bob

Most likely rebranded ceramic coating from any number of manufacturers:

Ceramic Coatings on ThomasNet.com

Some are better than others.

S