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Exhaust Manifold finish?

Csarneson

Jedi Hopeful
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I've been doing a lot of sand blasting lately on my BN4. Next up is the rusty old set of exhaust manifolds. After blasting how should they be finished? Originality doesn't really matter to me but I want it to look mostly correct. High temp silver paint? Powder coated silver? Graphite powder spray?
 
Before I installed headers, I put a matt black ceramic coating on the manifolds. I shipped mine to Jet Hot (not sure of the spelling anymore). There are other companies around. I was happy with Jet Hot.
 
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I've had the best luck with this, https://www.eastwood.com/calyx-manifold-coating.html on my stock BJ8 while the manifold was still installed. Never flakes off and reproduces the origanal factory look. I used a ceramic coating on my race car headers to help control the under hood heat. If you're sand blasting the cast iron exhaust manifolds, this would be my choice. Easy to apply yourself, I used an air brush from Harbor Freights that I plumbed to use with my shop compressor. You just need to turn the pressure way down. https://www.harborfreight.com/quick-change-airbrush-kit-93506.html

https://www.cerakotehightemp.com/finishes/C-111Q/tungsten/
 
I watched N episode of Wheeler Dealers a few days ago and they did a Sunbeam Alpine and had the custom headers I believe ceramic coated. Reference was made that it lowered the engine compartment 20 degrees.(going from memory here). I had my stock BJ8 exhaust manifolds coated 3 years ago and they still look great.
 
Hi Chris
I coated mine with a paint they use for pot belly stoves. Don't know if it's an original look but I did it on my Morris and it's lasted for years.
Matthew
 
Wow. $70 for a pint? I'm sure it's worth it but wow. Is a pint enough?

I've done 2 sets of race headers with a pint and probably have enough for 2 more. The key is the blast profile, it needs to be "sharp", glass beads won't do it

Racer Headers.jpg
 
Some of those products mentioned above sound great. I have used high temp (suitable for exhaust temps) medium and darker grey paint in spray cans. It works well.
 
Dougie, do you feel this self-applied coating is as good/effective as the 'pro' stuff (e.g. Jet-Hot)?

For a simple OEM look with the benefit of lower under-the-hood temperatures, the DIY, "thin-film" ceramic coating system I've used is equal. If I ran a NASCAR or NHRA race car, which required full motor tear-downs and rebuilds after every event, I would go with Jet-Hots thicker (15-20 mils) system. It is more scratch and abrasion resistant when re-installing. I had a local company ceramic coat my race headers with my first engine build, the finished product was so thin, the blast profile began to rust even before installation (about a month in the garage). I took them back, they re-coated them and it lasted until I pulled the motor again (2 years). After inspection, adhesion lose and more rust, I knew I could do better myself with the right product.
 
Thanks. I sprung for Jet-Hot before I realized there were--ahem--more cost-effective alternatives. I'm hoping this cures the stumbling-on-hot-start problem.

manifold.JPG
 
Dougie,

Thanks for the Cerakote post. I have a pair of blockhugger headers I'm going to try on my Nasty Boy as I believe the Sunbeam Tiger cast iron manifolds I'm using are causing a loss of a rather large chunk of horsepower. Once I've test fitted the new headers I'll send them out for coating and since there are some Cerakote applicators I can drive to, I'll save a bunch of shipping. Interesting to note that Cerakote provides a material called Insulkote for coating the inside of the header and I've read it's very important to coat the inside for best thermal reduction. Insulkote needs to be oven dried, unlike Cerakote and the trouble I'd get in for using the family oven for this purpose would make using the placemats look like a minor rebuke. I found this description of manifold coating for Pierce Arrows very informative: https://www.pierce-arrow.org/features/feature28/index.php
 
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