break drums

[cadillacmike68]

TJ no kidding. never heard of break fading.   

And i changed my mind no drums.

I think it's when you get tired from too much break dancing. 

I paint my drums with engine enamel or caliper paint.

[INTMD8]

I'll offer my .02 likely worth nothing so take it or leave it 

Looking at it from another perspective, if there was an application I was intending to retain heat in would paint be an effective solution?

I would say no.

That being said, I think a drum brake is a better heat absorber than heat exchanger, and by that I mean it has enough mass to absorb the heat energy of braking but being a smooth exterior with no fins or ducted air to it not efficient at exchanging heat real time.

I don't think painting drums could have any bit of measurable reduction in braking performance.

They will stop very well until overheated and paint isn't likely to change that.

Just my opinion 

[Cadman-iac]

That being said, I think a drum brake is a better heat absorber than heat exchanger, and by that I mean it has enough mass to absorb the heat energy of braking but being a smooth exterior with no fins or ducted air to it not efficient at exchanging heat real time.

This is why I chose to change my drums to a later model year with the fins. They do extend farther from the inside of the wheel into the air flow. 
But I still painted them.

I've have experienced brake fade in several different vehicles over the years. None of them had painted drums at the time either.  It was  probably partly due to the small size of the drums in the first place.

The vehicles I kept I converted to discs in the front.
The only one I have not converted to discs is my Cadillac,  for several reasons I won't get into here, I went with the drums.

But I don't expect any problems because of the paint.

[Roger Zimmermann]

As somebody wrote, the factory did not apply paint to the drums because of the costs and at that time, the customer could not see that pile of rust. The drive shafts are not painted either because nobody can see that. Really? Not in Europe! Therefore, for export, the drive shafts are painted since some years.
On all 3 cars I restored, i had a 2-K primer on the drums and then a good coat of black paint. Heat exchange problem? With cars more than 30 years old? you have to drive them accordingly to their age and learn that when going down a hill, the transmission is there to avoid speed increase by using the gear lever and not the brakes.

[Michel 14]

Bien Roger

[Jason Edge]

TJ no kidding. never heard of break fading.   

Brake Fade --> https://en.wikipedia.org/wiki/Brake_fade

[savemy67]

Is it a problem to have the break drums sand blasted and painted?

Hello John,

No, it is not a problem to have the brake drums sand blasted and painted.  Attached are before and after pictures of one of my '67's rear drums.  Note that my car has finned drums to aid heat dissipation (cooling via the flow of air).  Also, the rear drum shown has no hub.  The drum is held to the axle flange via the wheel lug nuts.

If you are having your drums blasted and painted by a shop, you need to decide if you will have all machining/work (drums turned, new bearing races installed, new studs if needed, etc.) completed before or after blasting and painting.  If before, then you have to be careful that any blasting and painting does not damage or contaminate the recent machining/work.  If after, you need to be careful that any machining/work does not damage the paint. In this regard the rears are easier than the fronts.  The fronts have the hubs with which you need to contend - more risk of damage or contamination.

I did all my own blasting and painting.  I had the machining done before blasting and painting, and I took the time to prevent any damage and contamination from blasting and painting by covering any surface where the blast media and paint should not go.

If you plan to drive your car in such a manner as to worry about whether painting the drums will affect the ability of the drums to eject heat, then you should consider swapping to disc brakes.  As J. Bozin implied earlier, there are several physics/engineering papers/ articles/discussions about how coatings affect heat transfer in metals.  If you are really curious, you can find them on the internet and in a good library.  For me, corrosion is a terrible thing.  Anything I can do to prevent corrosion (rusting drums) without compromising performance (brake stopping power) is a good thing.

If you did not read in its entirety, Jason's link to an article about brake fade, the synopsis is that brake fade is a decrease in the ability of brakes to slow/stop a car.  Brake fade is usually the result of prolonged and or repeated brake application, generating heat build-up, causing the brake drum to expand away from contact with the brake shoes.  Fade can also be the result of high heat compromising the friction characteristics of the brake shoe lining or disc brake pad.  If you plan to drive often in heavy, moderate speed, stop and roll traffic, you might experience brake fade.  If you plan to drive where you regularly encounter a long down-grade, you might experience brake fade.  And you would experience the fade whether or not the drums are painted.

You can also experience brake fade symptoms without heat build-up when you drive through standing water and the brakes get flooded with water.  Most of the water will drain away quickly once you are on dry pavement, but you may experience no stopping power from the brakes for several applications of the brakes.

As a reminder, our cars weigh on average about 2 tons.  This is a tremendous amount of weight standing still.  When moving, the effect is of a much heavier object.  Please keep this in mind when driving.

Respectfully submitted,

Christopher Winter

[spolij]

Thank you  all for the info. The drums are at the vendor. It will take a week or so. $20 each.
Then new tires and top.

BTW Christopher my 66 deville weighs 4,475 lbs so "break fade"  would be more of a problem. I was always aware of the condition but now i know the name.
Thanks

[Jason Edge]

BTW Christopher my 66 deville weighs 4,475 lbs so "break fade"  would be more of a problem. I was always aware of the condition but now i know the name.
Thanks

Hi John, Not trying to be the grammar police, but it is brake not break.  Here's a good definition I grabbed off the internet:

As a verb, the word brake means to stop. As a noun, brake is a device for slowing or stopping motion. The word break means to smash or to shatter as in to break a cup. It also means to take a recess, as in a coffee break.

[spolij]

Jason  Break got it! Thanks. JK