I assume you have to use VHT primer first that I cannot find at the Auto Zones. I sprayed them ( before assembly and were perfectly clean) without a primer, they looked good but burned off to a dull grey. Any advice ???

First off, you should just continue your other thread about the same question and not start a new one on the same topic.

Maybe your exhaust manifold is exceeding the heat rating of the paint. Go for a drive at night and see if your exhaust manifold is glowing red. If so, you are running too rich and therefore, too hot.

Once again, I didn't use any primer, just followed the baking sequence as best I could with a regular oven.

No peeling and only slight discoloration after two years.

There was another recent thread on this. I never found any kind of paint that would stay on the oem manifolds. It all either burned or flaked off pretty quick. I think a ceramic coating is the only possibility.

I wouldn't bother. If you really want to get the manifolds (and rest of the exhaust) coated, I'd try to find somewhere to get Titanium Nitrate coating for a decent price. Or standard ceramic coating for probably a lower price. If you don't prep and cure the paint properly, you'll almost certainly get it burning off and flaking like crazy.

I did my stock manifolds. Used the high temp primer and the ceramic header paint--baked it on car per instructions -- still on 2 yrs later

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Pat Jones

quote Originally posted by dobey: If you don't prep and cure the paint properly, you'll almost certainly get it burning off and flaking like crazy.

I prepped the manifolds by cleaning them thoroughly with mineral spirits and then acetone.

After painting, I oven baked them according to the directions on the can, except that I could only get to 550 degrees, not 650.

I'm very satisfied with the results.

Whats wrong with just a walnut or soda blasting, and leave them as is ? They are stainless.

quote Originally posted by rogergarrison: Whats wrong with just a walnut or soda blasting, and leave them as is ? They are stainless.

Titanium Nitrate coating would reduce heat soaking through the steel by up to 50% or so. Not sure how much it would cost for Fiero manifolds though. Getting Titanium manifolds made for a 2.8 would be a bit extreme, would probably cost more than the car is worth, and might not last very long since 2.8s can run rich and hit 900+F at the manifolds. Inconel would hold up, but also insanely costly.

I have done many sets of stock and aftermarket manofolds!/ headers. Never primed first, or baked in oven. I usually just drive the car. And have never had a issue with VHT paint of any color.
The only things that could cause a dulling issue or flaking issue is simply contamination, or too much heat for the paint. Ck your timing, I would bet your a degree or two to far advanced. Or a plugged cat causing a rich condition a stated earlier. Of its too far advanced that will also cause the manifolds too overheat and "burn" the paint. One of these things is the answer to your Question.........its all been covered more than once in both threads you have.
Brian
It looks like you have more work you do to make it pretty again

Well, after doing the gasket job, never again do I hope to remove the headers. Have be advised to mask off and repaint with VHT and cure it with the engine running off and on...OR...as someone suggested, paint the header with aluminum paint. YOUR THOUGHTS ON THIS ?????

quote Originally posted by 85fieroguy: Well, after doing the gasket job, never again do I hope to remove the headers. Have be advised to mask off and repaint with VHT and cure it with the engine running off and on...OR...as someone suggested, paint the header with aluminum paint. YOUR THOUGHTS ON THIS ?????

You can paint them any color you want, or not at all. Just make sure you use paint that can handle like 1200F temps, and prep the manifolds correctly before painting.