Getting ready to paint my engine and I'm reading conflicting info. Should I use self etching or epoxy primer?

Thanks!

Steel- metal prep and epoxy primer

Aluminum- cleaning agent/etch and epoxy primer

Thanks J. Just curious when do you use self etching primer?

Scott,

For small aluminum boat parts I use Zinc Chromate primer.
I just bought some at West Marine for my little antique Sea Kings.
Regular paint will not stick well to bare aluminum. Try it. Then put
some masking tape on the new paint area. The tape will take it right
off. Now for my Cobalt's aluminum parts instead of painting I went
with anodizing and powder coating. The anodizing process gives the
powder coat a good surface to bond to and powder coat just is
easier for me since I don't have painting equipment.

Depends on the part. I prefer epoxy because of the durability. You can also base right over the epoxy eliminating sealer and keeping film build down. The most impotant step is cleaning and etching the aluminum.

I've done other large projects like industrial trailers and airplanes where I used an etch primer and finished with Imron.

Thanks guys.

Dave, I do my own powder coating and will be coating all the brackets, valve covers, etc. But painting the engine and all the parts that can't be coated like pumps, dampener, etc.

J, what do you use to etch the aluminum? Only thing I am painting that is aluminum is the intake. I am going to chemically strip it down to bare aluminum. From there I can lightly blast it but it's a pita as my set-up is small. Are there chemical etchers out there? I was thinking that intakes are somewhat rough/porous so it wouldn't need much.

I don't have the #'s off hand. I can get back to you Mon when I get to the shop. Or ask the jobber you get your supplies from. I sanded and smoothed out my intakes before paint. A friend of mine clear powdercoated his.

I powdercoated this block in my old race boat , took 45 in over to get to 400 degrees . It was a waste of my time as powdercoat shows a ton of orange peel , when scratched it is tough to match . When you get down to it powdercoat is way over rated , I just blast, epoxy prime and paint . I sold my powdercoating business

i use ppg dp series epoxy primer on engine blocks..metal prep first o bare metal,if the engine is going to be black then dp 90,the dp will stick to anythimg and stay their,their are other colors available..when i did my intake over 10 yrs ago i just made sure it had no oils on it and out of the box i just sprayed imron clear over it,,still looks new..

Nice ! Imron 25 years ago was in a class by itself , today pretty much any urethane will do .