View Full Version : How do I paint an engine with surface rust?

09-01-2006, 11:12 PM
How do I paint an engine with surface rust? Can I use POR15 to encapsulate the rust, or can it not stand the heat? If I don't deal with the rust (too late to sandblast, as it has been rebuilt already), won't it come through even the best engine paint?

Ideas needed.


http://rocketdillo.com/studebaker/misc/images/Current_Avacar.gif[/img=left] - DilloCrafter

1955 1/2 Ton Pickup
[i]The Red-Headed Amazon
Deep in the heart of Texas

09-01-2006, 11:53 PM
Do the wire wheel on the drill thing. If you haven't already installed your engine. After cleaning the rust, wash with brake cleaner, first, then prep solvent and then use engine enamel. Anything worth doing is worth doing right. Get your wire wheels at Big Lots or Harbor Freight. A couple two or three ought to do. Possibly get the pack that has a few different sizes. jimmijim

09-02-2006, 12:28 AM
I use a 2-3 inch wire wheel chucked in a drill motor, 12V, 110V or air powered, whatever you have, also a hand wire brush to remove most of it. Clean with wax and grease remover for paint prep or Brake Clean. I have used ordinary low temp spray paint primer and then Engine Enamel. But most of the time, just Eng. Enamel and it works fine. I am sure everyone has their favorite method. You should be able to sandblast the water manifold, Intake and Exhausts and maybe even the heads without damage with a little masking.

Studebakers Northwest
Ferndale, WA

09-02-2006, 01:12 AM
The two response above are great and right on the money. But there are many ways to go about it. So I'm throwing out the method I used and the results just to show the variety.

When I restored my car I was a heavy user of por-15, it's everywhere inside and out, entire underbody and inside of panels...I wanted a car that will last 100 years. Being big into Por-15 I also read up on it's application on the engine. Like most places, they didn't have Studebaker 55' blue so I had to go with the Stude vendor spray enamels. However like you I was concerned about the base metal and any flashover that could come through. Either I read it or I talked to my por-15 people and they said stick it on before the enamel spray.

So I used the Metal-ready from por-15 which kills the surface rust and preps for por-15. They I put on a coat of por-15, then many coats of the spray enamel. The key is to get a high concentration of color pigment onto the engine, so it takes many coats and that way it survives the heat and lasts.

Results: 5 years and 30,000 miles it has worked good. There is no rust through with one exception. The intake manifold heat crossover gets very hot and I knew from the beginning that neither the por-15 or the spray enamel would last on that. After a year the heat burnt through and rust followed on that crossover, but hey other than that, the paint is solid and can be cleaned to a shine on both the block and heads and everywhere else. I was satisfied with the results and I know that the por-15 will provide a very long lasting base anti-rust coat for the top enamel color layer.

Hope that helps.

E. West
"The Speedster Kid"
Sunny Northern California
Where the roads don't freeze over and the heat doesn't kill you.
And an open road is yours to have -only during non-commute rush hours 9am-4pm and 7pm to 7am (Ha, ha, ha)

09-02-2006, 07:13 AM
I used Rust-oleum sray primer then spray can of engine paint. One year and 6,000 miles and no rust. I think the key is getting all the rust off.:)


09-02-2006, 05:55 PM
Thanks for the great advice, everyone!

I think I will combine all this into one, and do the following:
Use wire wheels on my drill, as well as the same thing but in a "poly-carbide abrasive circular brush" that I got at Harbor Freight today. It's described as "manufactured from nylon cord with polyurethane coating, impregnated with silicon carbide", and is billed as "ideal for removing rust, paint, etc...."

Then, since I have several 4 oz cans of Por-15 brush on black rust encapsulator, I'll use that as a base coat on the block. However, for the area around the manifold, I will brush on some of the POR-15 high heat exhaust paint, which I have an 8 oz. can of lying around unopened. After all that, I will brush on their red engine paint (can't tell whether I should go with their Chevrolet Red or their Ford T-bird Red: http://www.prp-porstore.com/page/por15/PROD/Topcoats/EE). But I have to paint this over the black within the 4-12 hour window after the black dries, or else it won't stick (ask me how I know). I'll also paint it over the high temp paint around the manifold. I know the red will burn off eventually, but at least rust won't come through that high temp stuff.

http://rocketdillo.com/studebaker/misc/images/Current_Avacar.gif[/img=left] - DilloCrafter

1955 1/2 Ton Pickup
[i]The Red-Headed Amazon
Deep in the heart of Texas