What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Black Paint Advice

rvanstory

Well Known Member
I am working with Scheme Designers on a paint scheme for my RV10. I REALLY like a particular design, but there's a catch. The top 1/3 of the plane over the cabin is black (which looks great) but I'm worried about the heat it will trap in the cabin.

Here's my questions:
1. Anyone actually have a black plane top to know from experience how much extra heat it will generate? If you did do this, would you advise me to avoid it?
2. Since 2/3's of plane is white, will heat from black top "dissipate" to other areas of plane? In other words, will all of plane be slightly hotter, or will only the black area be much hotter? Since there are so many engineers on this site, thought someone would know this answer.

I know there will be many opinions about "visibility". Not really asking about that. My concern is about heat. Really like the style, just want it to be functional too.
 
Black absorbs heat. It does not dissipate it.

Keep in mind that the top of the cabin is fiberglass. Fiberglass does not play well with very dark colors.
At one time Lancair painted one of their aircraft red and embedded thermocouples within the fiberglass. The results were not good for the longevity of the structure.
 
Heat Abosrbtion

There are loads of graphs on the net about colour heat Abosrbtion. Black absorbs all colours if light and relents none so will result in a much hotter surface than all other colours.

Black is not a good idea, and a bad idea on fibreglass which is why most glass aircraft are painted white. I don't like white for an aeroplane because it can make an aeroplane disappear against a whit cloudy background.

I painted a Tailwind fuselage black and regretted it because of how hot it got inside even in cold England. It was ok in the winter but in the summer in 27 c oat, it as like a sauna inside.
 
My RV4 was painted black and I really liked it. It was warmer on the ground but in flight there were no issues. It was VERY visible in the air, many pilots noted that.
There are thousands, likely millions, of black cars and trucks and they do not melt away.
I had a lot of people tell me it was a bad idea but I liked it and had no problems with the black fibreglass or paint. None of the folks who said it was a bad idea had ever owned a black plane so their opinion carried no weight with me.
 
My RV4 was painted black and I really liked it. It was warmer on the ground but in flight there were no issues. It was VERY visible in the air, many pilots noted that.
There are thousands, likely millions, of black cars and trucks and they do not melt away.
I had a lot of people tell me it was a bad idea but I liked it and had no problems with the black fibreglass or paint. None of the folks who said it was a bad idea had ever owned a black plane so their opinion carried no weight with me.

An RV 4 is a very different animal to a 10. The 4 does not have a fibre structure for the roof and door frames. None of the fibre on a 4 is structural. Comparisons with cars is only relevant for the non metal parts.

I actually love black, both of my cars are black, but again there is significant heat increase in the cab of a car because of the black colour in the summer, an RV 4 has a clear bubble canopy where it can get pretty hot, but nothing like the black painted fuselage on the tailwind I had.

I would have liked black on my 4 but my experience on the tailwind made me decide on a bright yellow, very conspicuous but much cooler on hot days.
 
What Mel Said. Light colors only on fiberglass or you will exceed its Glass Transition Temperature on a sunny day on the ramp.
 
Is black on fiberglass worse than on metal for any reason other than heat?

The issue is that with any fiberglass that the epoxy is room temperature cured, it will get soft as you heat the surface. Heat it enough and the structural integrity may be impacted.

Ever wondered why all the Rutan designed aircraft are all white?
 
Last edited:
You might find this interesting:
http://www.paintsquare.com/news/?fuseaction=view&id=13869

I've been casually looking into Paliogen pigments and the technology of heat reflective dark colors.
http://www.dispersions-pigments.basf.com/portal/basf/ien/dt.jsp?setCursor=1_559806

There are two approaches:
A black appearing pigment that passes through the IR spectrum to a reflective color under the top coat, i.e. black over white.
A black appearing pigment that reflects the IR directly. It seems these may not appear as "black" though.

So, it looks like it could be done with a bit of personal work, since I doubt your local paint shop will have any clue about these pigments. Pretty leading edge paint science for the automotive world anyway.

and you though building airplanes was just learning about riveting and deburring!
 
Black Eagle

My Christen Eagle II is all black with the feathers in various shades of purple, blue and pink. I love it. My cowling, wheel pants, canopy skirt and various fairings all in fiberglass or carbon fiber have been fine over 30 years. I live in Houston, TX where the heat / sun / humidity is scorching. Paint it the way you want. I am sure the life of your aircraft will not be compromised by black paint. Hugh Heffner's plane was all black (except for the little white bunny on the tail)

Just put a light color primer underneath :)
 
Corvette

Not to throw a wrench in the works but isn't the Corvette body fiberglass? Maybe I'm missing something.
 
Not to throw a wrench in the works but isn't the Corvette body fiberglass? Maybe I'm missing something.

Yes, but it is also not room temperature cured either. It is the room temperature curing that is the issue with the epoxy resin softening.
 
When I was young I had a dark VW with black interior, and a summer job at Quonset Point NAS where the car was parked on the blacktop ramp. At 5 pm I could not enter the car, it was that hot. I had to open the doors and let it cool for a few minutes. I have never since bought a dark car.
I don't know the temperatures needed to compromise the cabin top strength in a -10. But for sure, if you park on a ramp on a warm sunny day, a black paint job will decrease the lifetime of your upholstry and avionics, and be (more) unpleasant for you and your passengers (unless you have external power air conditioning) when you get in.
So, assuming the epoxy is okay, you just need to decide if the cost and unpleasantness of the heat is worth the look.
 
I know this is talking cabin top in black, but this is a tidbit just regarding the color.

I have 2 friends with RV-10's with black on their leading edges of the wings. Mine are white. There is a very very significant difference in temperature between the 2 when they're sitting in the sun. One of the 2 guys has commented to me that when he parks on the ramp he has to leave a couple gallons of fuel out of the tanks because with the black it heats up so much that it'll dump a lot of fuel overboard if he fills it all the way up. Mine dumps a little when it's hot too, even being white, but black is a significantly hotter color. At least on the aluminum you have no worry about structural integrity, but as Bob mentions, the type of epoxy cure on the RV-10 cabin top may not be the best candidate for black paint, since it's a structural top.
 
Several issues have been raised. Another one is that a black cabin top is going to get hotter and expand through thermal expansion more than a white top. There have been many reports of cracks around the cabin windows. The thought is those are due to the different thermal expansion coefficients of the materials involved. I think black paint will make that problem worse, not better.

That said, there are plenty of dark (blue, burgundy) cabin tops out there. I wonder how they are doing with regard to cracks around the windows??
 
Yes...and...No!

Not to throw a wrench in the works but isn't the Corvette body fiberglass? Maybe I'm missing something.

The Corvette body is actually FRP, Fiberglass Reinforced Plastic.
 
Last edited:
Ask Vans

Tech support at Vans should be able to advise on the thermal consequences, or lack of same, of black paint on the cabin top's structural integrity.
 
Window frame cracks

SNIP
There have been many reports of cracks around the cabin windows. The thought is those are due to the different thermal expansion coefficients of the materials involved. SNIP

I've seen several RV-10s with window frame cracks. While I'd assume a dark color would aggravate this issue, I offer the root cause is not properly finishing the glass to cabin top joint. On my plane I first took some micro and filled/smoothed the joint. After sanding, I put down a couple of bids of fiberglass over the joint. The fiberglass does not extend over the glass beyond the cabin top frame that the glass is glued to. That was followed by the normal micro-sand-micro-sand routine. I'm happy with the results. 500 hours over five years and no cracks.

Carl
 
The RV-10 cabin top is vacuum bagged / oven cured prepreg. fiberglass (some of the discussion seemed to be implying it was room temp cure epoxy).

This would have a better tolerance of the temps that would be induced by a black finish coat when compared to room temp cure, but I have no data to provide that would convince me to say go ahead....

If you would like to do your own research contact Mike Daniels at M&W Fiberglass. Ask him what the material is that they use and then research tolerance of long term exposure to temps that can occur with black paint (more research).
 
Thank you all for your advice and insights. Thought I'd share what I've learned so far from this post for the benefit of future readers considering the same issue.

I've never heard of "glass transition temperature" and didn't know what that was. So, with the issue of safety coming into question, thought I'd look deeper into the subject.

According to the mother ship (Van's), black on cabin top is not an issue structurally. Fiberglass top is made from same material and process as the cowl, which routinely sees very high temps from engine heat and does not suffer any loss of strength. The structure will not weaken due to the heat of dark paint. They pointed out that on Cirrus, it's an issue since the wing spars are carbon fiber. Carbon fiber IS affected by temp more than fiberglass. Support also said that the strength of cabin top would only be an issue if you flipped the plane over on it's top. It's not an issue in flight.

So, at this point it's the opinion of Van's that the issue is one of comfort only. (Which is still a major consideration.)

After stewing on this a few days, I am starting to lean away from "black" and am looking at more of a "charcoal gray". Might mitigate SOME of the heat (not all) while still giving me the high contrast look that is so appealing on the design.

Thank you all for your responses and insights!!! Very helpful!
 
Good to know

As part of my paint scheme I want to do dark grey around the windows and door columns to give that whole area a unified dark look in conjunction with tinted plexi. I wish I had saved a picture of what I'm talking about. I feel like the rest of the cabin should be lighter color unless you have real AC, not an ice chest and fan like I'll probably settle on.
 
Just a quick data point to confirm some of the information shared above...

The Glastar from Stoddard-Hamilton (prior to Glasair) was shipped with white gel coat. It used a vinyl-ester resin in a vacuum-bag layup process for the fuselage. Dark colours were not recommended for this aircraft as the transition temperature was something around 200 degrees.

The Sportsman from Glasair is a natural outgrowth/evolution of the Glastar. It is made using the same brand of vinyl-ester resin, however it's a different part number of resin. The change in part number changed the transition point from around 200 to around 300 degrees. Dark colours are not a problem for the Sportsman.

Even a minor change in resins can result in a major change in their properties. This is an area where one has to be very sure of the chemistry in use. I'm glad a definitive answer has been obtained from the manufacturer.
 
As I understand it, the cabin top is a structural member subject to being able to take the load in the event of a roll over. With that in mind, the UK LAA issued a Mandatory Mod requiring the paint to be of a pale colour to mitigate against any heat-related reduction in strength.
 
Back
Top