break drums

[spolij]

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

[Cadman-iac]

I certainly hope not! I've done it for years without any problems.  Just be sure to keep the braking surface clean and free of paint.  Otherwise blast away.
Rick

PS: You can blast the braking surface. It won't hurt it. In fact,  if the drum has a glazed surface it will help to create a better braking surface.  You can achieve it this way instead of by sanding it with paper.

[Dave Shepherd]

Can't be too aggressive  on the lining surface, it can cause some pitting.  This would require resurfacing the drums.

[The Tassie Devil(le)]

Plus, don't paint drums as this spoils the heat dissipation process.

Bruce.

[Cadman-iac]

Plus, don't paint drums as this spoils the heat dissipation process.

Bruce.

Bruce,  I was unaware that painting them hindered the heat dissipation. How does it do that? I've always painted mine.  It tends to get cooked off over time though.
Curious about this,  Rick

[The Tassie Devil(le)]

Rick,

The paint tries to reflect the heat back into the drum from whence it is coming.

The only reason engines are painted ids to make them look good, but engines have water to cool them, unless it is air cooled, then no paint.

Bruce.

[Cadman-iac]

Rick,

The paint tries to reflect the heat back into the drum from whence it is coming.

The only reason engines are painted ids to make them look good, but engines have water to cool them, unless it is air cooled, then no paint.

Bruce.

That makes sense. I've noticed that the paint won't last that long anyway, but it's nice to keep them from rusting before you ever get to use them. That's the main reason why I paint them.
Once you take the vehicle out and perform the shoe burn in/break in procedure, the paint begins it's disappearing act anyway.
But that's just me.  Thanks for the correction.
Rick

[spolij]

So just sand blasting is kind of a waste because they will rust pretty quick.
They are hidden anyway. ( Not going for a show car. )

I wouldn't think painting would cause too much heat. The only time you use breaks is to stop. Red light, stop sign your garage. All at a slow rate of speed.
But you made me realize no one will see them anyway.

The same goes for the rims, hidden by hub caps. But i am going to blast and paint them.

Thank you all. Saved me some money ! lol

[Cadman-iac]

So just sand blasting is kind of a waste because they will rust pretty quick.

Well that's why I paint 'em. If I didn't blast 'em, then they wouldn't have to be painted.
I guess it boils down to personal preference.  I wanted it to look like it was new, even though I know better.
I blasted all my  drums and the wheels.
The wheels needed it more so than the drums.
  And yes, it is all hidden, but maybe it's just me, but it bugs me to leave the stuff all rusty.
I never really thought about the paint keeping the parts from cooling.  But how much can it block?
Something to look into now.
Rick

[The Tassie Devil(le)]

So just sand blasting is kind of a waste because they will rust pretty quick.

Only need cleaning if they are really crappy, as in the steel part in the centre is rusting.

I wouldn't think painting would cause too much heat. The only time you use breaks is to stop. Red light, stop sign your garage. All at a slow rate of speed.

If only that was true.   So you never brake hard, or have experienced brake-fade?

The same goes for the rims, hidden by hub caps. But i am going to blast and paint them.

Rims are different.   need painting as these things will rust if not treated.

Bruce.

[The Tassie Devil(le)]

...... I never really thought about the paint keeping the parts from cooling.  But how much can it block?
.... Rick

Depends on what sort of paint is used, and how thick, till it burns off, then it stinks for a while, and makes a mess.

If they were supposed to be painted, then the factory would have painted them, or the replacements would be painted when one buys them from the shop.

All the makers put on them for the replacements is a protectorant finish, which had to be removed before fitting.

Bruce.

[Cadman-iac]

Only need cleaning if they are really crappy, as in the steel part in the centre is rusting.If only that was true.   So you never brake hard, or have experienced brake-fade?

Bruce.

Hey Bruce,

Yes, I have had that happen before.  But it was on my old 66 truck when it still had the original drum brakes.  I hadn't done that to it back then as I didn't have any way to blast them,  and what was the point of painting them if they were rusty?
That's when it got converted to discs.

As for the Cadillac,  the parts were very rusty. Thus the blast and paint.
Rick

[Cadman-iac]

Depends on what sort of paint is used, and how thick, till it burns off, then it stinks for a while, and makes a mess.

If they were supposed to be painted, then the factory would have painted them, or the replacements would be painted when one buys them from the shop.

All the makers put on them for the replacements is a protectorant finish, which had to be removed before fitting.

Bruce.

Good points all. But not to be argumentative, I was watching the Barrett-jackson auction today and they had several cars that had had the drums painted as you could see it thru the wheels.
Not that it is right or correct,  but it was done for who knows what reasons.
I guess what it boils down to is what do you want.  If you want a 100 point vehicle, don't.  If it doesn't matter to you, go ahead.
If you're concerned it will effect the operation,  don't.
I do it to preserve the parts since I don't have any way to coat the drums with cosmolene or another preservative.  Oil would work,  but oil will collect dirt quickly.
Paint is cheap, stops rust, and doesn't collect dust,  so to me, it's the best option.

Please don't think I'm arguing with you about this.  All I'm saying is that it's up to you if want them painted,  and I probably should have said as much initially.
I hope that clarifies things.

Rick

[spolij]

Bruce
"If only that was true.   So you never brake hard, or have experienced brake-fade?"
I understand. But if your doing 55mph and have to hit the breaks hard it only lasts a minute. You think that's enough heat to hurt the painted drums?
If they were supposed to be painted, then the factory would have painted them, or the replacements would be painted when one buys them from the shop.
Good point.
Rick my rims and drums are SUPER rusty. I never really thought about the paint keeping the parts from cooling.  But how much can it block? That's how i feel. I guess what it boils down to is what do you want.  If you want a 100 point vehicle, don't.  If it doesn't matter to you, go ahead.
If you're concerned it will effect the operation,  don't. Very informative LOL

OK It's cheap enough I'm back to blasting and painting the rims and drums.

[cadillac ken]

1:  Just because the factory never painted the brake drums doesn't mean it was for brake performance reasons.  The factory did a lot of
     stupid stuff to save $$ in production.

2: I've gotten brake fade in all my cars with drum brakes-- even the ones with unpainted drums.

3: Heat retention may be a fact but how much?  Guys have happily done mods to their engines and have boasted of a 8HP increase--- that
    was completely unnoticeable while in the driver's seat.

I guess you could apply the same theory to the exhaust manifolds. Never painted from the factory.  But there are plenty of guys running exhaust manifolds that have been ceramic coated and high temp painted without engine overheating issues.

just my .02

[fishnjim]

I'll spare the dissertation on heat transfer. 
Always check the dimensions of those brake wear parts, so that they're in spec for thickness and roundness.   They are cast, so are brittle.   No sense putting work into a worn out/bad drum.   The preferred method for dressing the interior of the drum is "turning", not sand blasting.
Coloring drums was not an issue until the wheel designs allowed viewing the brakes.   Steel rims & hub caps covered everything back there.   Only the purview of the mechanic.   
Once "mag"/wire wheels arrived (again) someone thought they looked a bit dodgey and wanted to dress them.   '50s designers even got in the act with wheel well color, etc.    But we're not allowed to talk about the competition here...   Now we have powder coated calipers, etc. in every color of the rainbow.
It was not uncommon in the hot rod days to see chromed exposed brakes.   I think another manufacturer even used aluminum drums and those were adopted too.   

Brake fade comes from expansion due to temperature increase.  Plus lining stiffness changes a bit w/ temp.   ie, Why some linings are better than others.   I doubt anyone's running trans AM with their dyno-soar.   Much ado...

[cadman56]

Don't know if this is true or not, but my radiator shop advised to use radiator paint.  It seemed to work and stay on m drums a long time.

[spolij]

Ken   what is break fade?

[TJ Hopland]

what is break fade?

Are you actually asking what brake fade is?   Or just poking a little fun at how confusing the English language can be?

[spolij]

TJ no kidding. never heard of break fading.   

And i changed my mind no drums.