So as I'm rebuilding the engine on my 914, I've been repainting the sheet metal with, and I know it's not the best way but my budget is limited, spray paint. Not just any spray, it's Dupli-color Engine Enamel- a ceramic rated to 500 degrees. Problem is, the primer gray is showing through no matter how many coats I put on it. One piece must have about 20 coats on it and still the gray is showing through. I finally got to the point where I said screw it and sprayed on a really thick coat on one piece, telling myself that when it cured I'd just sand out the runs and put on a lighter top coat to finish, but even that isn't working. Any ideas if it's just the paint, or maybe I should just switch to a black primer? Thanks.

Oh, and by the way, if it makes any difference I'm using gloss black as opposed to flat or semi-gloss.

Is the primer compatable with the paint?

I had good luck with the duplicolor engine enamel. it needed 5 coats, but none of them were thick.

Zach

I guess I didn't think about that. I'm not sure the brand of primer I'm using but it's not from dupli-color. I'll try to find it next time I'm at the parts shop. Thanks.

I have gotten really good results with dupli-color engine enamel on top of dupli-color primer on my gas tank. Needed just one coat of both to get the job done. How much time are you allowing between coats? Are you by chance spraying any brake cleaner or something like that on the surface and not letting it dry completely?

What do you mean the primer still shows? Are you getting fish-eyes? Round spots where the red won't cover the gray. If so, your part has some kind of oil or something still on it. You need to wipe the part down with lacquer thinner or a product specific for paint-prep. But LT always works good.

There's no chance there's any oils or lacquers like that on the sheet metal. Besides using gas to clean all oil and grease off (if needed, not all of them did), each piece has been cleaned thoroughly with a wire brush, then sanded to get rid of as much surface rust as possible, then wiped down with a clean rag, and then blasted with air just to make sure there's no dust on them. I've put a lot of work into prepping the metal itself before spraying on the primer.

I appreciate the advice, and any more y'all can give me is welcomed, but at this point I'm going to get some black duplicolor rustproofing primer and try that. The primer I'm using now is rustproof, but I think the problem is that it's a light gray and for some reason the black just isn't drowning it out.

Thanks again.

Because I couldn't find a powder-coater willing to do my tin, I ended up using the Dupli-Color engine primer and paint (low-gloss). I also used it (gray) on the fan housing and intake tubes. I waited 10 minutes between coats and 7 days between primer and color. The low-gloss black covered the primer completely by the second coat and I think I did 3 coats of color total.

Click to view attachment

Looks great. I inquired with Duplicolor regarding their paints. Durning the video tuturiol they had, they said it needs to be baked. How well does it hold up when it is not? here is there responce to my email.

Me "If I am unable to bake it at the reckomended 300 degrees for 2 hours? Will the paint cure ok if left to dry on its own? Thanks, Tod."

Responce " It is necessary to bake the High Heat products, otherwise, they are permeable by contaminants and considered uncured and can be easily damaged. "

Curious to see what experiences you all had with non-baked paint. I need to do alittle touch up on mine as well.

I used Duplicolor engine enamel too and it came out well. I didn't bake it. I guess time will tell if it holds up well, but its been on there for over 2 years and still looks good.

good deal jim. sounds like its durable enough ill have to try it.

Well I can think of two problems you have...

1) you wiped it down with Gasoline... that leaves behind residue. You need to wipe it down with a solvent made for that. This would be a pre-clean like RM 901.

2) Obviously your paint and primer do not like each other. The paint is not bonding to the primer. This sometimes happens when you say buy an enamel primer and a laquer based paint. Always best to go with a pheonolic (sp?) primer... you can put most anything over that.

Not my call but I would start over. Sand it off and start again fresh... using the correct prep and finish.

I don't think you should use gas as a cleaner, it comes from petroleum (oil)...Use Laquer Thinner or mineral sprits at least...

I also think you will have to use Duplicolor primer or have bad results...

Mine came out great...

2-OH!

Isnt using for anything other than putting into gas tanks dangerous, harmful, and illegal? Use the proper tool for the job always! In this case, denatured alcohol would be an excellent thing to use, or thinners like the above mentioned. Gasoline has a lot of additives in it now that DONT evaporate. Why do you think carbs gum up with varnish from sitting with gas in them? because it DOESNT all evaporate.

quick answer about baking. on engine parts, running the engine will bake it. it is not fully cured until baking and until such time it is easily scratched and stripped off by things like brakleen. if you wait to bake the paint by running the engine don't be shocked if it "smokes" a bit (first time I did that I was searching for a couple days to find why my engine was smoking everywhere)