Prep new cast manifold for paint

[yakelys69]

The exhaust manifolds I purchased came sealed in bags with a coat of oil. I plan to paint them with VHT per the instructions. I usually use some metal prep etch but am looking for a good suggestion on how or what to clean the oil off with first.

Any suggestions?

 

[BoulderMike22]

I was instructed to use mineral spirits on my cast block before paint to rid it of oil.


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[73azbronco]

VST sells a paint prep for brake calipers (spray on wipe off, smells like most solvent based cleaners), my guess is it would work fine on those before paint. The manifold paint does require a run in to cure the paint fyi.

 

[Steve83]

...looking for a good suggestion on how or what to clean the oil off with first.

Water. Lots of water. Preferably hot. Letting them soak will make the oil rise to the surface, so don't lift them back through that oil film - pour it off if possible. Some detergent (Dawn dish soap), surfactant (PurplePower/SimpleGreen), or alcohol (ethanol, isopropyl, whatever) in it will help break up the oil, but always finish with plain hot running water. Then let them dry thoroughly (in the sun or an oven) before priming.

 

[broncodriver99]

Brake clean does a good job. I have tried the prep and pre-cleans but at the end of the day a $3 can of brake clean does just a good of a job. If they are soaked with oil dawn dish detergent and hot water followed by a brake clean rinse once they are dry should do it.

 

[jmangi62]

Brake clean does a good job. I have tried the prep and pre-cleans but at the end of the day a $3 can of brake clean does just a good of a job. If they are soaked with oil dawn dish detergent and hot water followed by a brake clean rinse once they are dry should do it.

^^^^^ This is exactly what I did to paint my exhaust manifolds, worked great, plus my 47yr old manifolds look brand new. ;D

 

[September 1972]

Clean as correctly stated by our esteemed members. One more thing would be advisable which I learned recently by reading the directions on a very expensive batch of industrial epoxy. Hit it with a clean torch to burn off the oil. You don't need to torch the hell out of it, just a quick pass. The test is if it rusts quickly. Use white paper after 10 minutes because the rust is hard to see. If the air is dry boil some water below the manifold, if it doesn't rust then scrub with hot Dawn and water and re torch until it does rust. Once it rusts scrub it again and torch and place in oven to 150F for 20 minutes and place the paint in boiling water for 20 minutes and spray a light coat as a primer. I use Dupli color engine enamel good to 500F with a beautiful shine. With the manifold hot dump the paint on as fast as you can but don't drip it and after 5 hours air dry you can bake it for 2 hours at 350F in your wife's oven when she is away. It will be awesome and chemical resistant.

 

[broncodriver99]

place the paint in boiling water for 20 minutes and spray a light coat as a primer.

And wear heat resistant gloves because if the can doesn't explode and paint the inside of the old lady's kitchen it is going to burn the shit out of your hands while trying to spray the manifold and may even auto ignite when it vaporizes coming out of the spray tip and is exposed to oxygen. Then again it is more likely to just explode while sitting in the pot of boiling water on the stove.

 

[yakelys69]

Thanks for all the replies, also Steve83 thanks for some of your old posts that have helped me out a number of times.

 

[September 1972]

Ha Ha no no do not paint in her kitchen she will go into orbit!

And I meant put the can in boiling water and turn off the flame and let it heat soak, not boil the shit out of it! I snapped the valve out of a full can of spray paint and was pissed off so I wasn't going to throw it away without a fight. I boiled it then let it sit in the water for 20 minutes and placed it in a 6 inch hole in the yard and covered it up with dirt and a piece of 18 gauge sheet metal and drove a pick into it. That little bitch rose out of the earth like the devil and lifted the sheet metal enough to spray paint and ruin my shoes.

 

[Steve83]

I used Rustoleum, but the primer is remarkably hard-to-find. I think I got it at Lowe's, even though they don't sell the matching paint. And I think it was away from the spray-paint aisle.



But I haven't run that engine yet.

 

[66 Bronco Dave]

Wash with white vinegar water 3 parts water 1 part vinegar scrub let dry then rinse with water. The vinegar will convert any rust to a paintable surface and cut oils. It's the best cheapest way especially with cast Learned that from a guy in Texas he is on YouTube