Exhaust manifold restoration - 66 BB

[Joe R.]

I am in the process of restoring a 66 427 / 425 hp engine. The exhaust manifolds a very rusty. How should I go about restoring them?

Joe

[Ridge K.]

Re: Exhaust manifold restoration - 66 BB

Joe, I haven't restored any, but Steven Blackmer started a thread on this subject late in 2007. It you do an archive search of "exhaust manifold restoration" in the archives, you can find the many posted replies he got with good advice.
I'm torn myself, as I have a very, very nice original set for my Corvette, but hate the thought of them looking like rusted junk in a few years. However, what I take from past discussions is that if you do anything that appears to be non-original, it will get a substancial ding in judging.
I think the archives will lead you in your considerations. Ridge.

[Mike M.]

Re: Exhaust manifold restoration - 66 BB

Try Jerry MacNeish, He did mine 5 years ago and there like new still. You will get a small deduct for a coating but well worth the deduct as I hate rust.

http://www.z28camaro.com/index.html

[Kenneth B.]

Re: Exhaust manifold restoration - 66 BB

I am in the process of restoring a 66 427 / 425 hp engine. The exhaust manifolds a very rusty. How should I go about restoring them?

Joe

JOE
I sand blasted mine in a cabinet blaster. Make sure not to have the pressure too high & move the nozzle back and forth as not to make the cast iron look too shiny. As long as they are not exposed to moisture they will stay gray for a Long time. To clean rust discoloration I use a
household rust stain remover.

KEN

[Michael H.]

Re: Exhaust manifold restoration - 66 BB

I am in the process of restoring a 66 427 / 425 hp engine. The exhaust manifolds a very rusty. How should I go about restoring them?

Joe

The restoration of your manifolds isn't at all difficult. Most restorers glass bead the surface, while others have the manifolds dipped in some sort of rust removal process.
However, if you choose the glass bead process, be SURE to thoroughly wash the manifolds in lacquer thinner before applying the orange paint.
If you paint the manifolds orange while bolted to the engine, (best) it will automatically include the bolts, washers and bolt lock straps.
A medium coat of orange on all of the outer surfaces and some light mist on the inner surfaces will do.
I wouldn't use orange that is "high heat resistant".

[Joe R.]

Re: Exhaust manifold restoration - 66 BB

Guys,

Thanks for the advice! I am leaning toward sending them to Jerry MacNeish. I'm with Mike with regards to rust. I'm not planning to have it judging any time soon, the car is in rough shape. Will they still take a little bit of orange paint overspray after Jerry's treatment?

Joe

[Mike M.]

Re: Exhaust manifold restoration - 66 BB

You will have to cast paint them and bake them in your barbi to cure after you get them back from Jerry. He provides the paint. Then you can spray the orange on if you like. Mike

[Joe T.]

Re: Exhaust manifold restoration - 66 BB

The restoration of your manifolds isn't at all difficult. Most restorers glass bead the surface, while others have the manifolds dipped in some sort of rust removal process.
However, if you choose the glass bead process, be SURE to thoroughly wash the manifolds in lacquer thinner before applying the orange paint.
If you paint the manifolds orange while bolted to the engine, (best) it will automatically include the bolts, washers and bolt lock straps.
A medium coat of orange on all of the outer surfaces and some light mist on the inner surfaces will do.
I wouldn't use orange that is "high heat resistant".

There is another method that involves an electrolyte bath and low voltage source (like a battery charger). Search on the net in Google or Yahoo for "Rust remediation" or something similar. I haven't tried it YET, but it sounds safe and simple. It converts ferrous oxide (red rust) to ferric oxide (black rust or black iron oxide) that is much more durable. Forgive me if I mixed ferric and ferrous, but that's the concept. There is no acid or corrosive agent involved and there is little or no loss of mass. Once you rinse the converted items after the treatment in clean fresh water, they are ready for coating of your choice and no further neutralizing is necessary. One item: Cast Iron is VERY porous.Dry the items with low heat long enough to drive any residual moisture out or the coating won't adhere. I wish I had found this before I did my exhaust, then I could have told you whether and how wll it worked...Good luck...Joe
PS: I am trying to find someone that will do this to my frame as well...jt

[Mike M.]

Re: Exhaust manifold restoration - 66 BB

All the methods mentioned will eventually rust. What I like about Jerry's method is they will never rust.

[Joe T.]

Re: Exhaust manifold restoration - 66 BB

All the methods mentioned will eventually rust. What I like about Jerry's method is they will never rust.

That's probably true. My comment was a surface prep prior to a final coating solution. However, you won't get the immediate surface rust that blasting and wire wheel or brush get, since the surface is already oxidized. Just like cast iron cookware needs some surface protection, just not as quickly as raw iron or steel...regards...Joe