Painting My Engine Block - Suggestions Welcome

[qdeezie]

I finally got my 302 Ford engine block back from the machine shop.

They did a wonderful job of cleaning it down to the bare metal and what I want to do is wipe it down with lacquer thinner and paint it with Duplicolor engine paint.

My goal is to have paint that actually lasts and doesn't chip off.....well at least not for a few years if possible. I kicked around the idea of using engine primer prior to painting it. The color I am going with is cast aluminum. Does anyone have any experience or thoughts about high heat engine primer?

What are your suggestions overall on painting an engine block?

 

[dwcopple]

cast aluminum?=spray away my friend.

 

[Trav]

I would use a very thin coat of self etching primer with a couple of thin coats of engine enamel.
I have used this on aluminium and iron blocks with no heat problems, its really nice stuff. AA, AZ has it for under $8.

http://www.duplicolor.com/products/selfEtchingPrimer/

 

[sasilverbullet]

Originally Posted By: Trav
I would use a very thin coat of self etching primer with a couple of thin coats of engine enamel.
I have used this on aluminium and iron blocks with no heat problems, its really nice stuff. AA, AZ has it for under $8.

http://www.duplicolor.com/products/selfEtchingPrimer/


+1

You can also use Rustoleum's brand - they have an engine primer and paint also. I just used it on my air cleaner yesterday. I sand blasted to metal and then sanded it. Went on great, don't know how it will hold up.

Whichever brand you use, make sure you use their primer first!

 

[SuperDave456]

Everything in life has an appropriate primer.
I'm convinced that the difference in a professional job that lasts, and a job that you regret doing so poorly, is in the primer.

Never painted an engine. But I'd suggest to do the research on the appropriate primer.

Paint technology changes, just like Oil Technology. Do your research to keep up with the times, and keep us informed as to what you find.

 

[HerrStig]

Originally Posted By: SuperDave456
Everything in life has an appropriate primer.
I'm convinced that the difference in a professional job that lasts, and a job that you regret doing so poorly, is in the primer.

Never painted an engine. But I'd suggest to do the research on the appropriate primer.

Paint technology changes, just like Oil Technology. Do your research to keep up with the times, and keep us informed as to what you find.


I'd have it powder coated.

 

[meep]

years ago I rattle canned a few. They never held up as well as the block that i had come back from a machine shop with chevy red casually sprayed over it.

I think prep was a lot, however what we got in a can never seems as durable as what comes out of a gun. I've wondered if spray lacquer would hold up better--- it's harder than an enamel.

Newer paints should be better...

I have used wheel and rim paint by duplicolor on everything from wheels, to body, to engine/trans pans. if you let it cure for the full 7 days dries very tough. It's on the pans of my 3.8L minivan right now, 2 coats gray and 2 coats clear, and after a year has no nicks or blemishes. The engine runs at 195 and the transmission between 180-200 to the cooler.

 

[1 FMF]

the best advice i can give from experience is having the iron clean prior to priming. if the block came back from the shop after being tanked and washed then either paint is asap or protect it until you paint it. Use an engine primer rated to 500F which is usually gray. Duplicolor has cast coat aluminum which looks really good, I just did the aluminum intake on my truck with it and posted pics of here not too long ago. It covered over the gray primer nicely. the key is light coats within 5 minutes of each other with the primer to get good base coverage followed by coats of color. if you read the can, you need follow up coats within an hour of each other otherwise have to wait 7 days for it to fully cure- so you want to get it all applied properly which will make it durable. then the second step is heat cycling it to further cure it. the hard part is after the motor is painted when you install it and wrench on it not to mess it up.

https://bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2640854#Post2640854

 

[qdeezie]

I'm sure the instructions are on the can, but as a rule of thumb, how long do I let the primer sit before I apply the paint?

 

[qdeezie]

Well, here is what I did:

1) The obvious - Taped up the block with painter's tape and newspaper.

2) Took lacquer thinner and a towel and wiped the block down thoroughly.

3) Purchased a can of Duplicolor Self Etching Primer and applied 3 coats to the block.
Note: I waited two minutes between each coat.

4) Let the Self Etching Primer sit for 30 minutes after applying the 3rd coat.

5) Applied 3 coats of Duplicolor Cast Aluminum paint. Waited 10 minutes between each coat.

I will be giving the block a full 7 days to cure before doing anything else with it.

I know I used more coats of primer and paint than most, but we'll see if it was a good thing or bad thing. It was a fun thing to do, I do know that!

Thank you for your input and please continue to provide comments/input. I have plenty of primer and paint left over, so what I learn from this one will be applied to the next engine block.

I will also post pictures once it cures and the tape and newspaper is removed.

 

[1 FMF]

http://www.duplicolor.com/pdfs/tips.pdf

less than an hour, preferably as soon as you can.
like it says, enamel has a recoat window under an hour plus or minus given temperature and humidity. it works similar to applying coats of epoxy- where subsequent coats need to go on when the previous coat is still tacky so the stuff links together and becomes durable otherwise it will chip and flake. when i did my intake i was able to get everything on within 2 hours in my garage, that was 3 coats of primer and 3 of color. 3rd primer coat heavy then waited 30 minutes and did 3 coats color with the 3rd fairly heavy. you almost can't go too heavy, it's much easier than painting with regular enamel paint and nothing like using basic rustoleum enamel where that stays tacky for 6-8 hours.

 

[mechtech2]

Get a brush on paint. It goes on way thicker and is a nice fun job.
Plain old Rustoleum is great.

 

[tbm3fan]

Obviously the best thing would be Dark Ford Blue in a urethane paint. The next best thing, and you can get it, is the Eastwood Ford Blue and get a 1/2 pint can of activator. That will harden the paint similar to automotive urethane. You don't need a spray gun for it either since you can actually brush it on, let it flash for 10 minutes or so, and put another coat on. Mix 4:1 and mine had a long working time before setting up solid in the cup. Actually I'd use a spray gun for the valve covers buy mine are the crinkle Ford 302 so they don't need anything. A little goes a long way.

 

[GMBoy]

I've never primed an engine before painting. Probably the best way to do the job, but I've got a Jeep CJ that I rebuilt the engine 18 years ago and the paint is still looking good and not coming off. I just used VHT engine enamel in a spray can. Black color.