TheSamba.com :: View topic

Sun Mar 09, 2014 3:35 pm

A few weeks ago, I installed new rear brakes--new drums, too. It's been raining (finally) here in Northern California, and the drums are already showing rust.

I want to paint them, and I saw some nice silver rattle-can at Napa, specifically to use on drums and rotors (up to 500 degrees, it says on the can).

My question is this: what primer do I use?

It makes no sense to buy finish paint that can withstand higher hear that drums and rotors can produce, when the primer can only take 200 degrees, maximum. Or, do I really need a primer, at all?

Or, is it really necessary to use a paint that holds up, over the standard 200 degrees that most Rustoleum rattle-can paints do?

Anyone painted your drums or rotors lately? What did you use that has held up?

Tim

Sun Mar 09, 2014 4:28 pm

VHT has a primer SP118 High Temp Primer specifically for thir drum/rotor paint. Probably a real good system. Myself, Rustoleum rusty metal primer or their rust converter and rustoleum professional gloss black. Only time I had issues was when I had my brakes locked because I had the brake pedal pushrod set wrong.

Sun Mar 09, 2014 4:46 pm

Yep, VHT brake caliper paint is good stuff. If it'll hold up on oval track race cars, it'll hold up on a Beetle!

http://www.vhtpaint.com/products/caliperpaint/

Sun Mar 09, 2014 4:48 pm

I used brushed on black gloss rustoleum. Never overheated or changed colors, been about 3 years now

Sun Mar 09, 2014 5:15 pm

Whatever primer you use, be sure to get the drum surface as clean as possible before hand. Blasting would be best, but a steel rotary brush will do, but in any case, you should wipe the drum down with acetone a few minutes before priming it.

For the finishing touch, I've found that the canned "boiler paint" from ACE Hardware holds up at least as well as the best automotive "high temp" paints I've come across, and at half the cost. Granted, it only comes in grey or cream, and if you're only doing a couple of drums, cost shouldn't be an issue.

Sun Mar 09, 2014 6:48 pm

Don't most paints list compatble primers on their labels?

Sun Mar 09, 2014 6:58 pm

Don't paint drums...it inhibits heat transfer,which in turn reduces brake efficiency..

Sun Mar 09, 2014 7:13 pm

johnnypan wrote: Don't paint drums...it inhibits heat transfer,which in turn reduces brake efficiency..

I think you would have a really hard time showing that a few mills of paint will affect the heat transfer by radiation. Then you would have to wonder how a nice layer of rust would affect heat transfer. I guess manufactures have been screwing up for years by painting things like engine blocks? :D

Sun Mar 09, 2014 7:29 pm

Jeff_Birt wrote: johnnypan wrote: Don't paint drums...it inhibits heat transfer,which in turn reduces brake efficiency..

I think you would have a really hard time showing that a few mills of paint will affect the heat transfer by radiation. Then you would have to wonder how a nice layer of rust would affect heat transfer. I guess manufactures have been screwing up for years by painting things like engine blocks? :D

how many brake drums do you see painted? :roll:

Sun Mar 09, 2014 8:34 pm

Painted my '70 Beetle's brake drums with brush on Tremclad black 30 years ago. Car is still rotting away in the back yard today and the brake drums still look good! As an aside, it is common to find factory paint coatings on new cars, usually those whose drums are visible through the rims.