How to restore stock exhaust manifolds? ???

[jr1000yarder]

What's the best way to "paint" clean up my stock manifolds? ?

I know powder won't hold and for sure who does cerakote.

I'd like to keep them so I don't have issue running AC on my BBC

69 CST 396

Thanks

[Jason Banks]

You can see some I had JetHot coated in this photo

[Grumpy old man]

Well , once off start with some serious time and effort with a stiff quality wire brush , then move up to sand blasting ,then muriatic acid bath ,fresh water flush throughly then back to sand blasting . At this point they should be like new .wash with soap and plenty of water allow to dry and then recoat with the high heat cast iron coating of your choice . Safety glasses , chemical gloves and chemical respirator required .

[cdowns]

i'd just soak them in vinegar for a day or two they come out bright and shiny like new// no gloves required no respirator either and you can reuse the vineagar for salad dressing if you have unwanted company

[dfwright]

Has anyone used Calyx manifold dressing, and know how it holds up over time? When first used, it looks great. I haven't seen any "after" photos.

[jr1000yarder]

Originally Posted by cdowns

i'd just soak them in vinegar for a day or two they come out bright and shiny like new// no gloves required no respirator either and you can reuse the vineagar for salad dressing if you have unwanted company

does it just eat the rust and grease? do I need to protect the inside or gasket area in any way??

[Grumpy old man]

Vinegar does not eat grease or remove rust scale . It's cast iron start scrubbing and you won't hurt them and part of the cleaning process is the inside and mounting surface start scraping . This is one item that requires elbow grease ! Or take them to a machine shop and have them do the work for you and have them hot tanked .

[GRX]

Fine a good local machine shop with a bake oven and steel shot peen machine. Afterward apply a high quality brush on manifold paint and cure it in a gas grill.

[jr1000yarder]

OK thanks!!!!

[midniteblues]

From what I read online you dont wanna use the acid on cast iron because it's so porous so I just wanted to be safe in that matter.

Blasting would be best.

But...
I used a knotted wire wheel on a drill too do most of them.then a series of smaller ones too get into the crevices.

I also continued to smooth them out with grinding wheels and rolocs although this part isn't for stock resto.

Then used vht paints on them...it will probably burn off anyway.

That coating above is sweet.

[mike16]

bead blast them but be carefull of the dust generated, especially from bead blasting the inside of the exhuaste runners. the dust generated can contain toxic stuff including TEL.

[GRX]

Yes. Acid will absorb into the pores in the cast iron and leech out under the paint. Same goes for moisture. Which is why I recommended the baking process for complete drying followed by shot peening. Have done it that way for many customers with good results.