What colour?

On Sun, 03 Aug 2003 01:45:03 GMT, "John Nicholson"
wrote:

What are the factors that go into deciding what colour to paint your
aircraft?

I like some of the sexy reds (they go faster) and other colours but the fact
that most aircraft are painted white leads me to conclude that there is
something else to all this.

In my case, the aircraft will not (unfortunately) be hangared.

John

Metal, fabric, or compost?
As compost airplanes can go soft in the heat, like a giant cheese,
most are painted white to reduce heat absorption while sitting in the
sun.

The aircraft is a composite Lancair 360.

clare @ snyder.on .ca wrote in message
...
On Sun, 03 Aug 2003 01:45:03 GMT, "John Nicholson"
wrote:

What are the factors that go into deciding what colour to paint your
aircraft?

I like some of the sexy reds (they go faster) and other colours but the
fact
that most aircraft are painted white leads me to conclude that there is
something else to all this.

In my case, the aircraft will not (unfortunately) be hangared.

John

Metal, fabric, or compost?
As compost airplanes can go soft in the heat, like a giant cheese,
most are painted white to reduce heat absorption while sitting in the
sun.

The aircraft is a composite Lancair 360.

Looks like you should stick to the light colors, white, yellow, silver etc, and
keep the dark trim colors to a minimum.

I once took one of those infrared heat guns with me to the auto auction (1000+
vehicles) on a wind free day. While there can be some error with the IR units
I did come up with some real surprises - like silvers that get WAY hotter than
you would expect and some rather dark colors that weren't that bad. I suspect
there is more to how hot the paint gets than just the color, like the kind of
flake, pearl, or even the clear coat.

White is boreing, but it's the only fool-proof color I know to paint a
composite plane.

I once took one of those infrared heat guns with me to the auto auction

IR radiometer ?

Dan, U. S. Air Force, retired

"BD5ER" wrote in message
...
White is boreing, but it's the only fool-proof color I know to paint a
composite plane.

Well alrighty then....

The Germans have been building glass ships longer than anyone.
They are all delivered white with small patches of trim color,
usually high vis red/orange on the nose, wingtips and tail.
The anti-collision markings are JAR22 mandated, but the
white finishes arent. They probably know something we don't.

Scott

On 03 Aug 2003 05:18:46 GMT, cal (BD5ER) wrote:

The aircraft is a composite Lancair 360.

Looks like you should stick to the light colors, white, yellow, silver etc, and
keep the dark trim colors to a minimum.

I once took one of those infrared heat guns with me to the auto auction (1000+
vehicles) on a wind free day. While there can be some error with the IR units
I did come up with some real surprises - like silvers that get WAY hotter than
you would expect and some rather dark colors that weren't that bad. I suspect
there is more to how hot the paint gets than just the color, like the kind of
flake, pearl, or even the clear coat.

White is boreing, but it's the only fool-proof color I know to paint a
composite plane.

I saw some figures once from the world of architecture. it showed that
the infra red transmissibility performance of paints was considerably
different from the apparent colour.
since the thermal end of the spectrum is IR it would pay to do some
objective testing of the paints in that spectrum area before settling
on the favourite colour.
sorry but this was 20 years ago and I dont have access to the
publication. I can verify the veracity of your comments though.
Stealth Pilot
Australia

I once took one of those infrared heat guns with me to the auto auction

IR radiometer ?

"Heat guns" was a POOR choice of words. The only gun I pack as a Glock. G

Raytek non-contact IR pyrometer - would have been more accurate.

I used to be a gunsmith, you can keep your Glockâ„¢. I carry what goes with
what I am wearing. My 45 won't conceal very well with shorts.

Back in 1973 I used to work for a company that made IR radiometers. I guess the
difference between pyrometers and radiometers is in the eye of the beholder.

As for the emissivity of paints perhaps a single layer sheet of the composite
you intend to build your flying machine with can be used for tests. Paint small
spots with the actual paint you's like to use. Place the sheet out in the sun
and measure the temperature from the reverse side at each spot using your
radiometer. Do this as soon as you place the sheet in the sun. Then again at
each half hour interval there after including cool down times as the sun sets.
This will allow you to plot a rough curve for each colour.


Dan, U. S. Air Force, retired

As for the emissivity of paints perhaps a single layer sheet of the composite
you intend to build your flying machine with can be used for tests. Paint
small
spots with the actual paint you's like to use. Place the sheet out in the sun
and measure the temperature from the reverse side at each spot using your
radiometer. Do this as soon as you place the sheet in the sun.

Sounds like a reasonable test. If I only had the time. Mine will probably be
white.

I used to be a gunsmith, you can keep your Glockâ„¢

I intend to. 8 years, about 11 cases of ammo, 2 misfires from bad factory
ammo, and one from the gun due to stupid owner. It hits what it is pointed at,
now if I could just point it better...........Other than that I'm happy with
it.

Ran across a site of a fellow building a Falco. Naturally, he wanted
it red. Had the rudder painted, while the rest was still
primer-white. Measured the temp out in the sun one day and the red
rudder was waaay hotter than the white fin. He decided that a white
Falco was still fast and sexy.

The reason your silver aircraft may have showed up so hot is because
your "heat gun" was actually peering at the image of the sun reflected
off the glossy surface. But its is true, the apparent color seems to
have little correlation to its IR characteristics. The guy that
suggeted using the back surface of a test panel and measuring the
temperature directly (thermocouple into to DMM or non contact
thermometer) was right on. Also, you could always go two tone on your
airplane with the top surfaces being IR reflective (and preferably
visible light absorbative on the cowl) and the other surfaces any
color you want.

cal (BD5ER) wrote in message ...
The aircraft is a composite Lancair 360.

Looks like you should stick to the light colors, white, yellow, silver etc, and
keep the dark trim colors to a minimum.

I once took one of those infrared heat guns with me to the auto auction (1000+
vehicles) on a wind free day. While there can be some error with the IR units
I did come up with some real surprises - like silvers that get WAY hotter than
you would expect and some rather dark colors that weren't that bad. I suspect
there is more to how hot the paint gets than just the color, like the kind of
flake, pearl, or even the clear coat.

White is boreing, but it's the only fool-proof color I know to paint a
composite plane.