painting Cowls

[Dick Noble]

We have black A/C Cowl covers that have faded to a dull grey. I am thinking about painting them white. Can anyone think of a reason not to?

[RoJoSo]

Rust-Oleum would work very well.
Just be sure to wash and wipe down the cowling really well.
You then can paint it any color (mostly)

[traveldawg]

I painted the tops of mine white on my last motorhome. I always thought it was kind of weird that something meant to cool was painted black, a color I always thought retrained heat rather than reflect it.

I painted the inside of one of my covers on my current rig just to test it out without messing the outside up. Maybe I used the wrong paint. It didn't stick well. I think the key to painting them is to clean and scuff them up a bit; then maybe use some kind of primer for plastic.

[Hoopy Frood]

Yeah, it does seem weird, but black radiates heat better than white, so it makes sense that a radiator cover would be of a color that would radiate heat best. White reflects the sunlight/heat better but will not radiate the heat from the air conditioner as well as the black. Kind of odd, but physics sometimes is counterintuitive.

[traveldawg]

Yeah, it does seem weird, but black radiates heat better than white, so it makes sense that a radiator cover would be of a color that would radiate heat best. White reflects the sunlight/heat better but will not radiate the heat from the air conditioner as well as the black. Kind of odd, but physics sometimes is counterintuitive.

Yeah, I know. I just always have a hard time wrapping my head around that. But I always think about black cars sitting in the sun versus white cars. It just seems white would be cooler. I wonder what would NASA do. Somebody should stick a thermometer under each color cover to see what is going on.

[jkwilson]

I was up on top of mine in direct, hot sunlight a week or two ago, and was surprised to find the roof was hotter than the black AC covers.

[Riverbug]

We have black A/C Cowl covers that have faded to a dull grey. I am thinking about painting them white. Can anyone think of a reason not to?

Rustoleum makes paints specific for plastics. I have used it on outdoor chairs and PVC pipes and it holds up very well. Just prep the surface well. Scotch pads to scuff it up work great.

[Hoopy Frood]

Yeah, I know. I just always have a hard time wrapping my head around that. But I always think about black cars sitting in the sun versus white cars. It just seems white would be cooler. I wonder what would NASA do. Somebody should stick a thermometer under each color cover to see what is going on.

One way to tell, would be to have the interior temperature the same, and see whether the white car or the black cools off faster when out of the sun. Physics says the black car will cool quicker.

[Dick Noble]

I did wash them well and used a primer. I have coated the first one three times and I think it will take one more coat.

[Riverbug]

One way to tell, would be to have the interior temperature the same, and see whether the white car or the black cools off faster when out of the sun. Physics says the black car will cool quicker.

I'm just curious, what is the logic for black being a benefit because it cools faster when moved to shade vs the negative of it heating up more in the sun? I have also considered painting my cowls white because when in the sun (which is more often the case than not), it heats up so much more; just like the front cap and awnings do. I assumed the air conditioner would run more efficiently with white covers than black. But that's not the case?