Topic: Brake drum finish

[ruppstang]

What process are most using to achieve a natural cast finish on brake drums?

[CharlesTurner]

I've had good luck soaking in evaporust.  Otherwise, I would blast and then do a light 1 minute or so dunk in phosphate, followed by machining the proper areas. 

[67gtasanjose]

Just like all cast-iron surfaces, achieving the "new " probably isn't as difficult as maintaining them to look like new. This is when all available  "choices" may help for various environmental/usages  a project may be exposed to.  In a perfect world, there is no humidity and a restored vehicle is placed into a museum.

Personally, I like cleaning all of the rust off of items such as exhaust manifolds, brake drums, rotors and the likes and coating them with a suitable high-temp cast-iron colored paint followed by machining the surfaces that were originally machined.

I believe the reason that many brake drums and calipers with styled steel and or mag wheels (Shelby) were slathered in black paint was because even before the cars could be sold, those cast iron surfaces would often be rusted and ugly.

[RoyceP]

Agree, my experience with brake drums and a plastic drain pan filled with Evaporust was awesome. Way less mess than bead blasting and much better results.

I've had good luck soaking in evaporust.  Otherwise, I would blast and then do a light 1 minute or so dunk in phosphate, followed by machining the proper areas.

[J_Speegle]

Been playing with the idea of trying one of the exhaust manifolds dressing on the exterior surface of the brake drums (no machined surfaces) next time I do a set. Not the paints but the treatments. They are designed for high heat, don't alter the texture and should return them to an acceptable cast look or at least that's the plan. 

Just thought I would share that possibility since you asked.

[ruppstang]

I am going to have to blast, the PO painted them. I was thinking of using some blacking then T9 but am interested in Jeff's manifold treatment.

Jeff do you have a brand you like?

[jwc66k]

I recommend that you read the directions on the Evapo-Rust container, the next to the last paragraph:
"To prevent flash rusting, dip the item back into solution and allow to air dry. This will prevent rust for up to two weeks."
In other words, your rust removal task is done, but what comes after the two weeks?
Jim

[markb0729]

Do you think Boeshield T-9 would work?

[J_Speegle]

I am going to have to blast, the PO painted them. I was thinking of using some blacking then T9 but am interested in Jeff's manifold treatment.

Jeff do you have a brand you like?

Fall back would be the ceramic coating but would be tempted to try Calyx

Haven't used it yet but looks promising for the surface we're discussing. 

Do you think Boeshield T-9 would work?

Once you got the tone and tints as well as machined surfaces if any on your design, done first. Even with a finish  or dressing for the natural cast surfaces mentioned above your  still going to have to protect the other surfaces.

[markb0729]

Fall back would be the ceramic coating but would be tempted to try Calyx

I've used Calyx with success on exhaust manifold bolts but seems to come off easily.

[J_Speegle]

I've used Calyx with success on exhaust manifold bolts but seems to come off easily.

So its a coating rather than something that would tint and work into the metal?

Might try a liquid graphite followed. Just going to take some experimenting. If not back to ceramics or blueing applied with steel wool possibly.  Maybe watering it down with something else to lighten the affects. Looking for a medium flat or low gloss final look

[markb0729]

Yes, I would say more like a coating than something like gun blueing that works into the metal.

[67gtasanjose]

I just got an account opened at Tech Line for the ceramic coating Jeff uses on exhaust manifolds. I know two close friends with Kilns for the 1-hour bake at 700 degrees. I might try this out on an extra brake drum to see how it goes but the stuffs not real cheap (so not wishing to waist it too). Pondering the quart-size can but they sell 4 oz. containers too. I'll no-doubt go with a quart size to be safe

[ruppstang]

I have mine blasted but have not decided how I will finish them. I had some powder coated for a different car and they look good but not quite what you would expect on a concours trailered car.

[Bossbill]

Brake drums are actually a composite of the steel center hub cast into the cast iron drum surface.
I would expect the center to have a natural steel finish and the cast part to look -- well, cast. Not a mono-finish.

How are you guys accomplishing this? Want to see a few options compared to what I what to try.  We see few pictures of finished drums.

Fresh glass blasted with no finish: