Hi,
took out the exhaust manifolds on my '67 3.8s series. They are rusted, but assume with some sandblasting I will get them

cleaned up. I have been searching how to paint/cover them to get a practical but beautiful finish. Ceramic coating and enamel paint comes up a lot. Is there a big difference? And was the original a metal finish?

Thanks

 

The original finish was a porcelain, but I gather than it can't be reproduced now due to hazardous material in the process. I doubt that paint will survive long, as it needs to be exceptionally heat tolerant. On a long mountain grade I have seen 1100°C on an exhaust temperature gauge. Mind you, 1100 was as high as went... Just for reference, steel glows red hot at 750°C.

If you were to go for anything, I'd try ceramic coating.

If you just want to remove rust, you could try a chemical called Evaporust. It's an iron chleating agent and chemically converts the rust. Non-toxic and doesn't smell, it's nice to work with. Toss the manifolds in a bucket and cover with the solution, wait a day and the rust is gone.

 

the original shiny finish is still available from a business in Florida.

 

Thanks. I see there is a company here (South Africa) doing ceramic coatings, I'll give them a go.

 

I think the cost of sending exhaust manifolds from South Africa to Florida and back would be prohibitive!

 

Try to find some reviews or info from previous customers. From what I've read, some ceramic coatings look and last better than others.

As for the original type of finish, that from the factory didn't survive very well before cracking off and most of those who try to recreate it do even worse. So, again, if you find someone who reproduces it, check how it's worked for previous customers.

There may be local knowledge in the SA Jaguar Club or other historic vehicle clubs. Glyn might also be able to point you in a good direction?

 

My engine rebuilder had my exhausts ceramic coated black. Don't know where he took them because I fired him & we no longer speak ~ one John Bird. The shine did not last very well. They are still black but no longer shiny. Approaching matt black. I will ask around.

 

The original finish was vitreous enamel that, as said above, didn't last long. This enamel is still used for oven interiors and cooking trays etc, but most ovens don't get as hot as the manifolds, so they last, and last, (my Whirlpool oven is 15 years old and still good !).
A ceramic finish is probably the best, but the shine probably won't last long. You would think that in 2023, we could coat exhaust manifolds better than Jaguar managed to do in the 60s !

 

Vitreous Enamel will never hold up to exhaust manifold temperatures unless you drive like an old fart & even then will finally crack up.

My best bet would be on black chrome. It holds up on racing motorcycle titanium exhausts well with the characteristic blue tip. Typical of titanium.

 

I used this stuff on mine and followed the instructions.
It's this nice matt black finish and it hasn't turned white _ looks great.

I guess it depends what one wants.


VHT Flameproof™ Coating -- High Heat Coating (vhtpaint.com)

 

I'm happy with mine in semi matt black.

 

I have used the VHT product suggested by Jeff on exhaust manifolds, and it seems to hold up OK.
At least it does appear to protect the manifolds from reverting to rusty chunks.
Cheers

 

Good day, thanks for all the advice,

I'm tempted to use the VHT product, but might be kicked out of the house if I start curing exhaust manifolds in the oven.

 

Cure them on the car. Leave it idling & they will cure just fine.

 

It's an excuse for some full throttle acceleration in second gear 😀 ...

 

LOL

 

In regards using the VHT product on exhaust manifolds I think it is important to follow the manufacturers recommended procedure which is

• Paint must be completely dry before curing
• Run at idle for 10 minutes
• Cool for 20 minutes
• Run at idle for 20 minutes
• Cool for 20 minute
• Run under normal operating conditions for 30 minutes.
• A friend of mine who is into hot rods emphasised that if the procedure is not followed the paint might burn off.
• Cheers

 

I had a Cerakote finish professionlly applied to my exhaust manifolds. they have a web site. I got the high temperature product (1800 degrees) in what is called a Glacier Silver - their product C7700. Air Cured. You really need a professional to apply it though, and its a little pricey. I love the look on my manifolds !
Schmitty

 

I've seen suggestions of using graphite spray or paste/cream. Apparently you can scrub it into the manifold and the graphite stays in place giving a satin grey finish. Eastwood sell something called Calyx. Once done, I'd imagine it may be very difficult to apply any other finish. On the other hand, it should be easy to patch up if necessary.

 

We have a zinc based product called Threadtex. It's so zinc laden the cans are only half full. I painted it onto my Alfa exhaust manifolds & it lasted & looked great. (for the drilling industry collars & threads). The base oil burns off in no time.