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Old 09-09-2018, 10:20 AM
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rvator51 rvator51 is offline
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Default Best Paint for inside of cowl?

Any suggestions for what is the best paint to use for painting the inside of the cowling? I have squeeged on a layer of epoxy to seal the fiberglass and am going to use white paint over it followed by foil in the hot areas but not sure what paint works best for this application.

Thomas Velvick
Goodyear, AZ (KGYR)

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Old 09-09-2018, 10:22 AM
rocketman1988 rocketman1988 is offline
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Default Epoxy

I am planning on coloring the epoxy that I squeegee on the cowling...

Seems as if it would do double duty sealing and coloring...
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Old 09-09-2018, 10:27 AM
lr172 lr172 is offline
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Unless you are looking for cosmetics, you're done. The key issue is sealing the fiberglass and your epoxy did that well. Foil will adhere better to the epoxy than paint.

If you paint, I would go urethane. Rattle can / acrylic paint may not hold up to the heat. I just sprayed the inside of my cowl with a grey epoxy primer.

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Old 09-09-2018, 10:35 AM
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az_gila az_gila is offline
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Originally Posted by lr172 View Post

If you paint, I would go urethane. Rattle can / acrylic paint may not hold up to the heat. I just sprayed the inside of my cowl with a grey epoxy primer.

I used white epoxy primer so I didn't have to look at the pink color...

White also makes it look brighter and shows up oil spots/leaks better.
Gil Alexander
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Old 09-09-2018, 10:57 AM
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maniago maniago is offline
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You dont need to paint it unless you really want to, tho you do need to do the epoxy step to fill any pinholes, as youve already done. Obviously epoxy primer checks both squares. I used Akzo cause thats what I had, and still have. Then I scuffed it and squeegeed West Marine epoxy over it as I have it left over stuff from fiberglass work and its just going in the garbage otherwise. Dont over think it; you'll see oil stains (and therefore dirt) no matter what you seal it with.
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Old 09-09-2018, 11:43 AM
pilotkms pilotkms is offline
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+1 for white pigment added to the epoxy. Got mine from ACS. $6
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Old 09-09-2018, 12:01 PM
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Finish the inside just like the outside...epoxy seal, epoxy primer, two-part urethane paint. I like white because it shows the location of air and oil leaks.

Sure, nobody sees the inside of the cowl..until you try to sell it. Finishing details make all the difference.
Dan Horton
Barrett IO-390
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Old 09-09-2018, 03:38 PM
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I used Azko heat reflecting paint. Supposedly keeps top surface cooler and is easy to detect maladies.
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Old 09-09-2018, 06:42 PM
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I filled the pinholes in the top and bottom cowls with a 50/50 mix of epoxy and acetone. It goes on really thin and I used a 3" wide high nap roller to apply it. It took about four coats (and rollers) but sealed it well.

Then the bottom cowl was completely covered with a thin layer of aluminum contact heat shielding. it has held up well for 11 years.

As for painting the inside, I didn't bother. Nor did I paint my baffles. My thinking was that if I were to have a fire, the fewer paint fumes coming from the engine compartment the better. Truth is, this may never be an issue because I would suspect I couldn't smell the paint fumes over the oil and gas.
Bill R.
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Old 09-09-2018, 06:46 PM
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chrispratt chrispratt is offline
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I used the same paint and process - Sherwin Williams Acry Glo -- that I used on the outside. It has held up well for 13 years.

Chris Pratt (2019 VAF DUES PAID)
RV-8 Flying, 775+hours
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