TheSamba.com :: View topic - Brake Drum Painting-bad idea?

Sat Nov 15, 2008 12:03 am

I'm thinking about painting the outside of my brake drums. It occurred to me that painting the drums might affect their ability to disipate heat and reduce braking ability.

Anyone have any thoughts on that? Maybe I think too much :D

Sat Nov 15, 2008 12:48 am

Well, try wearing one of those thin wind breakers jackets in 100.f. You wouldn't think it would make a difference but it does. Thats what paint would do as thin is it is.
It wouldn't be that big an issue if thats all you did was go to the grocery store and back, but you have to realize that the brakes create a HUGE amount of heat in just a few stops.

But i don't think there would be that big a deal just to paint the facing of it, (the wheel mounting side) tho.
You have to remember tho that your wheel also acts like a heat sink for your drum or disc. Try feeling you WHEELS after you get stuck in rush hour traffic and when you get off the freeway. You'd think the freeway would get hotter.

My 2 cents worth :)

Sat Nov 15, 2008 8:01 am

I always put a nice light coat of BBQ paint on my brake drums after I have been in there cleaning and servicing them.

Keeps them from getting all rusty , but I am the only one that ever sees them also.

Sat Nov 15, 2008 10:05 am

Hiya All,

Jay, you present an interesting point of view. Certainly logical.

But I think I'm with Randy on this one. Quite a few engine rebuilders paint their cases flat black to help dissapate the heat. Wouldn't that principle also work on a brake drum? And consider this, an unpainted drum will develop a rusted coating. Wouldn't that also serve to insulate somewhat? Don't know the answers for sure, but I'm thinking "yes" to both of them.

In any event, I have also used the BBQ paint approach on the drums and have had no negative effects in any kind of driving. Works for me.

Sat Nov 15, 2008 10:40 am

I painted mine with high heat engine paint. They tell you to use primer...I 've found that that actually makes the paint flake off. I just clean the metal parts I'm painting with a soap/water solvent , let dry and paint. Been doing it for years and the paint hasn't faded or flaked. I have pieces on my motorcycle that are on the engine that I painted in '03 and they look like I painted them yesterday.

Sat Nov 15, 2008 12:14 pm

Interesting question.

I go with the every change, changes something else philosophy. The question here (I think) is the change significant? I suspect not, but I would think painting metal would have some effect on cooling ability also depending on what type of paint you use

.

Sat Nov 15, 2008 1:06 pm

Go ahead and paint them. The affect on the heat dissipation is inconsequential.

Sat Nov 15, 2008 1:49 pm

Painting cases is bad. It holds the heat in.
VW had trouble back in 1968 with wheels coming loose. They discovered that they were putting too much paint on the drums. When it got hot, the paint would soften, and allow the lug bolts to come loose. We cleaned a lot of paint off brake drums on a recall. To this day, you may find some lug nuts drilled for safety wire.
If you are going to paint your drums, put a very light coat on around the lug bolt holes.

Sat Nov 15, 2008 2:00 pm

i'm with ovalteen on this.... i do the same on my rear brakes and havent had any problems :)

Sat Nov 15, 2008 2:23 pm

Good advice from Russ W. about the application of the paint.

Sat Nov 15, 2008 4:12 pm

paint them, been doing it for years, wont hurt a thing.

Sat Nov 15, 2008 7:39 pm

Mudpump wrote: I'm thinking about painting the outside of my brake drums. It occurred to me that painting the drums might affect their ability to disipate heat and reduce braking ability.

Anyone have any thoughts on that? Maybe I think too much :D

I actually put a coat of rust bullet on mine before painting them. I spoke to the chief engineer at rust bullet and we spoke at length. He said 1 coat of rust bullet would be negligable to heat dissipation.

I have had them painted for 2 years now and during my last brake inspection they looked great (just like new drums) & the pads & drum surface were fine.
My bug brakes perfectly!

Sat Nov 15, 2008 7:56 pm

bowtie56jw wrote: paint them, been doing it for years, wont hurt a thing.
X2 :roll:

Sat Nov 15, 2008 8:01 pm

i have to think that painting it flat black would actually help with the dissipation of heat, i read in the engine section somewhere flat black paint helps dissipate the heat quite a bit more than other colors, (especially chrome), but thats besides the point, i think you can if you want to.

just my 2 pennies

UG

Sat Nov 15, 2008 8:44 pm

Russ Wolfe wrote: Painting cases is bad. It holds the heat in.
VW had trouble back in 1968 with wheels coming loose. They discovered that they were putting too much paint on the drums. When it got hot, the paint would soften, and allow the lug bolts to come loose. We cleaned a lot of paint off brake drums on a recall. To this day, you may find some lug nuts drilled for safety wire.
If you are going to paint your drums, put a very light coat on around the lug bolt holes.

I smile every time I hear that little tid bit,

I don't know why,

I also have found myself repeating it.