exhaust manifold coatings?

[Jeff M.]

I have used the eastwood manifold paint in the past and have found that it has bleed throuhg of rust after the first winter. Yes i sand blast them before painting. Does anybody have a better idea? I have heard that powder coating does not work either

[Hank D.]

Re: exhaust manifold coatings?

I've used Cast Iron Grey from Bill Hirsch with good success.

http://www.hirschauto.com/prodinfo.asp?number=EMPT-PINT&variation=CST%20IRN%20GR

[Stephen L.]

Re: exhaust manifold coatings?

I've used a HIGH temp cast blast paint which has lasted for years......

[Patrick H.]

Re: exhaust manifold coatings?

Jeff,

If you want them to last "forever" then consider sending them to Jerry MacNeish. He will coat them, and then you spray Seymour cast blast over top. No rust ever again.

John Hinckley has them on his 67, FYI.

Patrick

[Jeff S.]

Re: exhaust manifold coatings?

I've always used graphite hi-temperature lube to achieve the gray iron casting look without the "painted" patina. It lasts for years with little or no maintenance & costs about $4/can from industrial supply houses. (You'll never find this at Wally World or FLAPS) Manifolds must be carefully prepared -- this is not a procedure that can be cobbled together with manifolds installed on engine, etc.

Bead blast, followed by compressed air blow down, followed by good wiping with MEK or lacquer thinner. Do a couple light coats of the aerosol; it flashes over in about 10 seconds and can then be handled. Roll up a piece of newprint into a ball, and buff very lightly to knock down any high spots on the sand casting puckers. Your done -- no smell or curing needed.

[Jerry W.]

Re: exhaust manifold coatings?

I had my engine rebuilder use VHT( cast iron color )...clean...bead blast ...apply VHT....oven cure....results are outstanding....looks like picture that Jeff posted.

[Joe L.]

Re: exhaust manifold coatings?

Jeff,

If you want them to last "forever" then consider sending them to Jerry MacNeish. He will coat them, and then you spray Seymour cast blast over top. No rust ever again.

John Hinckley has them on his 67, FYI.

Patrick

Patrick-----


I had brand new NOS manifolds for the "ZL1" done by Jerry. They're still absolutely PERFECT after 5 years. Of course, the engine has yet to be fired up. I have every expectation they'll hold up perfectly once it is fired, though.

By the way, I think John's Z-28 is a 1969 (unless he's recently also purchased a 1967, which I doubt).

[Joe R.]

Re: exhaust manifold coatings?

Hi Jeff:

If you check the archives, you will find enough different methods being advocated to create some serious brain overload. Most of the methods described look pretty good when fresh, but some do not hold up well over time, especially if you drive your car a lot.

When I was taking my car through the NCRS judging process, I simply bead blasted the manifolds and put them on the car. They looked great, judged well, and held up fine for a few years because I didn't drive the car much between judging events.

Now that I'm just driving my car, I'm making some changes that are less NCRS correct but likely to hold up well over time. For protecting the exhaust manifolds, I wanted something that would last "forever." In reviewing the archives, I was heavily influenced by the fact that both Joe Lucia and John Hinckley had selected the Jerry MacNeish method for their own cars.

I purchased a set of reproduction manifolds with the 2.5 inch outlets (my original 67 manifolds have 2.0 inch outlets) and had them coated by Jerry MacNeish. Jerry's method appears to create a thin coat of aluminum on the manifold that is thick enough to prevent rust but thin enough to leave the texture unchanged. He then has you apply conventional VHT SP998 high temperature cast iron paint. The theory is that what defeats most paints is moisture getting through them and causing rust underneath, so the rust-proof coating followed by a good high temperature paint should hold up well.

I just put the manifolds on my car this past weekend. Attached is a photo of what they look like after 50 miles of driving. I'll be interested to see how they look after 10,000 miles of driving, but right now the jury is still out.

At this point the paint color seems to have developed a slight bronze tint from the heat, but it still looks okay to me. A fellow chapter member put his manifolds (also with the Jerry Macneish treatment) on last weekend too and noticed the bronze shift after driving. Worse, though, is that the paint on his manifolds started to peel. He has a call into Jerry to try and figure out why. So far I have no peeling on my manifolds, and I'm keeping my fingers crossed.

[Patrick H.]

Re: exhaust manifold coatings?

Patrick-----


I had brand new NOS manifolds for the "ZL1" done by Jerry. They're still absolutely PERFECT after 5 years. Of course, the engine has yet to be fired up. I have every expectation they'll hold up perfectly once it is fired, though.

By the way, I think John's Z-28 is a 1969 (unless he's recently also purchased a 1967, which I doubt).

John's Corvette is a 67.
Isn't this a Corvette discussion board?

And yes, his Camaro is a 69. But, Jeff has probably seen his 67 Corvette more frequently.

[Patrick H.]

Re: exhaust manifold coatings?

Hi Jeff:

If you check the archives, you will find enough different methods being advocated to create some serious brain overload. Most of the methods described look pretty good when fresh, but some do not hold up well over time, especially if you drive your car a lot.

When I was taking my car through the NCRS judging process, I simply bead blasted the manifolds and put them on the car. They looked great, judged well, and held up fine for a few years because I didn't drive the car much between judging events.

Now that I'm just driving my car, I'm making some changes that are less NCRS correct but likely to hold up well over time. For protecting the exhaust manifolds, I wanted something that would last "forever." In reviewing the archives, I was heavily influenced by the fact that both Joe Lucia and John Hinckley had selected the Jerry MacNeish method for their own cars.

I purchased a set of reproduction manifolds with the 2.5 inch outlets (my original 67 manifolds have 2.0 inch outlets) and had them coated by Jerry MacNeish. Jerry's method appears to create a thin coat of aluminum on the manifold that is thick enough to prevent rust but thin enough to leave the texture unchanged. He then has you apply conventional VHT SP998 high temperature cast iron paint. The theory is that what defeats most paints is moisture getting through them and causing rust underneath, so the rust-proof coating followed by a good high temperature paint should hold up well.

I just put the manifolds on my car this past weekend. Attached is a photo of what they look like after 50 miles of driving. I'll be interested to see how they look after 10,000 miles of driving, but right now the jury is still out.

At this point the paint color seems to have developed a slight bronze tint from the heat, but it still looks okay to me. A fellow chapter member put his manifolds (also with the Jerry Macneish treatment) on last weekend too and noticed the bronze shift after driving. Worse, though, is that the paint on his manifolds started to peel. He has a call into Jerry to try and figure out why. So far I have no peeling on my manifolds, and I'm keeping my fingers crossed.

Joe,

did you install gaskets? It appears so in your picture.

If so, I think you may be sorry in a year or two. I burned through a set a year on my 71 until I finally took them off, had the manifolds resurfaced, and put them back on the car. Zero problems since then.

Patrick

[Rick S.]

Re: exhaust manifold coatings?

Here is a photo of my exhaust manifolds almost 4 years after having them powder coated. Approx 7k miles on them.
Rick

[Joe R.]

Re: exhaust manifold coatings?

Joe,

did you install gaskets? It appears so in your picture.

If so, I think you may be sorry in a year or two. I burned through a set a year on my 71 until I finally took them off, had the manifolds resurfaced, and put them back on the car. Zero problems since then.

Patrick

Hi Patrick:

Yes, I put gaskets on this time. There were gaskets on the car when I bought it several years ago. I had taken the gaskets out for NCRS judging and experienced some leakage. Subsequent investigation showed some warpage at the center sections of the manifolds, which I painstakingly corrected (or so I thought).

When I took the old manifolds off for this installation, I saw some carbon tracks indicating that there was still just a little bit of leakage. I figured that since this configuration isn't going to be judged, I would put gaskets in just for insurance. I'm not sure I actually needed them because the 2.5 inch manifolds are brand new reproductions, but I didn't think it would hurt.

What was the failure mode that you had with your gaskets? Did pieces come off and cause audible leaks?

The gaskets I put on are just standard Napa gaskets with a metal facing that I presume faces the manifold. At least that's the way I installed them.

[Timothy B.]

Re: exhaust manifold coatings?

When I resurfaced the 2.5" exhaust manifolds on my 63, the machine shop plained them on a bench sander. After installing them I discovered they were not flat so I removed and used a sharp metal file with a straight edge and did the job myself..

When I finished them, they were glassbeaded then blown off and the VHT high temp cast iron paint. The oven bake was done when wife was not home but I think this makes a difference..

I realize the 63 should be orange but this looks much better to me. If I ever painted them orange I would just go over the VHT, it's good stuff..

[Patrick H.]

Re: exhaust manifold coatings?

Hi Patrick:

Yes, I put gaskets on this time. There were gaskets on the car when I bought it several years ago. I had taken the gaskets out for NCRS judging and experienced some leakage. Subsequent investigation showed some warpage at the center sections of the manifolds, which I painstakingly corrected (or so I thought).

When I took the old manifolds off for this installation, I saw some carbon tracks indicating that there was still just a little bit of leakage. I figured that since this configuration isn't going to be judged, I would put gaskets in just for insurance. I'm not sure I actually needed them because the 2.5 inch manifolds are brand new reproductions, but I didn't think it would hurt.

What was the failure mode that you had with your gaskets? Did pieces come off and cause audible leaks?

The gaskets I put on are just standard Napa gaskets with a metal facing that I presume faces the manifold. At least that's the way I installed them.

Joe,

I installed the exact same type, and they slowly crumbled away, leaking and making noise. After the 3rd set I went ahead and had them surfaced at the machine shop with no problems since then.

Patrick