ConcoursMustang Forums

Restoring - General discussions that span across many different groups of years and models => Processes, Products & Techniques => Topic started by: ruppstang on February 28, 2019, 09:34:57 PM

Title: Brake drum finish
Post by: ruppstang on February 28, 2019, 09:34:57 PM
What process are most using to achieve a natural cast finish on brake drums?
Title: Re: Brake drum finish
Post by: CharlesTurner on March 01, 2019, 12:14:51 AM
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. 
Title: Re: Brake drum finish
Post by: 67gtasanjose on March 01, 2019, 06:23:21 AM
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.
Title: Re: Brake drum finish
Post by: RoyceP on March 01, 2019, 11:18:47 AM
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.
Title: Re: Brake drum finish
Post by: J_Speegle on March 01, 2019, 02:41:05 PM
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.
Title: Re: Brake drum finish
Post by: ruppstang on March 03, 2019, 09:52:49 AM
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?
Title: Re: Brake drum finish
Post by: jwc66k on March 03, 2019, 04:32:09 PM
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
Title: Re: Brake drum finish
Post by: markb0729 on March 03, 2019, 09:46:04 PM
Do you think Boeshield T-9 would work?
Title: Re: Brake drum finish
Post by: J_Speegle on March 03, 2019, 10:42:24 PM
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.


Title: Re: Brake drum finish
Post by: markb0729 on March 04, 2019, 12:29:36 AM

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.
Title: Re: Brake drum finish
Post by: J_Speegle on March 04, 2019, 12:33:55 AM
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
Title: Re: Brake drum finish
Post by: markb0729 on March 04, 2019, 04:59:57 PM
Yes, I would say more like a coating than something like gun blueing that works into the metal.
Title: Re: Brake drum finish
Post by: 67gtasanjose on March 04, 2019, 06:39:58 PM
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
Title: Re: Brake drum finish
Post by: ruppstang on March 04, 2019, 07:33:08 PM
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.
Title: Re: Brake drum finish
Post by: Bossbill on April 19, 2020, 06:57:14 PM
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:
Title: Re: Brake drum finish
Post by: J_Speegle on April 19, 2020, 07:07:30 PM
Style of drum is going to vary depending on application and supplier

Here are some original service pieces that have been posted earlier and some new ones, that show finish and contrast as well as untreated/messed with cast surfaces

Hope they help

(http://www.concoursmustang.com/forum/gallery/5/6-050616182932-58491071.jpeg)

(http://www.concoursmustang.com/forum/gallery/5/6-050616182929-58471853.jpeg)

(http://www.concoursmustang.com/forum/gallery/5/6-050616182927-58462200.jpeg)

(http://www.concoursmustang.com/forum/gallery/5/6-050616182930-58481760.jpeg)

(http://www.concoursmustang.com/forum/gallery/13/6-190420180600.jpeg)

(http://www.concoursmustang.com/forum/gallery/9/6-230218223441.jpeg)

Title: Re: Brake drum finish
Post by: Bossbill on April 19, 2020, 10:02:49 PM
That's a fair bit darker than I thought.

Do you have any of the rear drums? I'm interested in the bolt up surface.

Thanks again!
Title: Re: Brake drum finish
Post by: J_Speegle on April 19, 2020, 11:09:49 PM
Will look for some rear drum examples Only the bottom picture has one on a Shelby from 65 at the SA factory (top right corner) Slightly darker face might suggest its been blacked out but not a great picture for this detail
Title: Re: Brake drum finish
Post by: ng8264723 on April 22, 2020, 09:42:55 PM
Southern polyurethane primer works awesome on a black.  IT should be fine on drums a swell.  They don;t get over 200.  Then use a rattle can for the top coat..............