Hi Rob
As I wrote
"I am not going to encourage anybody to paint their
Europa=B4s undersides any colour but white. I still well
remember Manual=B4s words: all the Europas must be white."
and
"I think - with other colour as white - it is better to be even more
careful. "
and
"Keep your full matt black Europa in the hangar and fly only night time
if
you wanna be absolutely sure"
Anyway - I called to my friend Jukka Paavolainen, who has build
and still flies his Lancair 320 OH-XJP. He said his Lancair is
just on ordinary glasfibre - epox system and definetely not baked
in high temparatures. Only the cowlings - because of the engine and
exhaust heat - has been made by more heat resistant phenolresins.
His Lancair kit is year model 1990 and so is my earlier example SE-XOP,
which is overall deepred and beautiful Swedish Lancair 320.
I believe newer models are as you described made by adanced composite
materials.
You wrote
" Park on a black surface and the solar energy absorbed by that surface
will be re-radiated to the underside of the aircraft, and if that
aircraft is any color but white it will absorb too much energy. "
and I still think you are wrong. I am going to talk to one
thermodynamist,
who works as a doctor in Tampere Univercity. Maybe he can make this
thing clear. I promise to come back and tell what he know. Also if I am
wrong...
Fly it - do not melt it...
Raimo
----- Original Message -----
From: Rob Housman
To: europa-list@matronics.com
Sent: Friday, July 20, 2007 6:02 PM
Subject: RE: Europa-List: Europa colours
Sorry Raimo, but this is dangerous thinking for those of us flying in
warmer climes.
In my previous post I deliberately avoided getting into too much
technical detail, and I used the word "reflected" where I should have
used the technically correct term "emitted."
First, you seem to misunderstand heat transfer. You are correct that
the sun's energy is not reflected from a black surface. However, a
"black body" is not only a perfect absorber but also a perfect emitter,
which is to say it may not be reflecting solar heating but it surely
emits it. Park on a black surface and the solar energy absorbed by that
surface will be re-radiated to the underside of the aircraft, and if
that aircraft is any color but white it will absorb too much energy.
Any material absorbing energy will increase in temperature. Sure, there
will be some re-radiation from the dark aircraft structure but that is
irrelevant because the epoxy-fiberglass will already have softened.
Second, the Lancair aircraft all use a different composite than
Europa. Here's how Lancair describes their composites on their web site
http://www.lancair.com/Main/legacy.html ---
"Like every Lancair, the Legacy's major airframe is constructed of
advanced composite materials. Cured at 270 degrees Fahrenheit under
vacuum pressure, these NASA tested, epoxy based composites are among the
lightest, strongest, stiffest materials known.
The high-temperature, pre-impregnated carbon fiber and/or fiberglass
systems combined with Nomex/honeycomb core materials are considered the
supreme composite airframe materials of choice worldwide."
Note that the Lancair's composites are cured at a much higher
temperature than the factory and we cure the Europa structural
components. The "glass transition temperature" is approximately the
cure temperature so softening of the composite does not begin until
approximately T sub g is reached. For a detailed explanation to T sub g
see http://en.wikipedia.org/wiki/Glass_transition_temperature For our
purposes we can consider the glass transition temperature the softening
temperature, above which the structure loses a significant portion of
its strength.
Anyone contemplating painting a Europa any color other than white
(including yellow) should review the chart in the Builders Manual,
Figure 1, Colour-Temperature Relationship, on page 36-1 of the Europa XS
Tri-Gear Manual, Issue 1, dated 30 May 1998.
Best regards,
Rob Housman
Irvine, California
Europa XS Tri-Gear
S/N A070
Airframe complete
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of Raimo
Toivio
Sent: Friday, July 20, 2007 1:28 AM
To: europa-list@matronics.com
Subject: Re: Europa-List: Europa colours
Rob,
I am not going to encourage anybody to paint their
Europa=B4s undersides any colour but white. I still well
remember Manual=B4s words: all the Europas must be white.
I still have to point out the energy of the sun is NOT
reflecting out of the black asphalt IMHO. That is why
it is hot when a sunny day. It absorbs allmost all the heat
energy and nothing is reflecting out. White surfaces are
cool because they are reflecting out much more.
So it could be more dangerous to keep it on the snow covered
surface while a sunny day (or on white sand or water w Europa
floats!).
In Sweden there has been 10 years a wonderful full colour mid red
Lancair 320
and no composite problems at all. Register # is SE-XOP (!). And like
we all know in South America (Columbia?) there is flying a total deep
yellow Europa.
I think - with other colour as white - it is better to be even more
careful.
Beauty is a good reason for some extra work and some sacrifice.
That is the fact all the women know. That is all.
"Keep your full matt black Europa in the hangar and fly only night
time if you wanna be absolutely sure"
Raimo
----- Original Message -----
From: Rob Housman
To: europa-list@matronics.com
Sent: Friday, July 20, 2007 2:32 AM
Subject: RE: Europa-List: Europa rules
Mike -
In re: dark paint
Don't even think about it. Where we live and fly, on warm days the
heat reflected off the ramp will be sufficient to soften the
epoxy-fiberglass enough to reduce the strength of the structure. Sure
it will be OK at altitude but you still have to climb away from the
surface. Folks flying closer to the Arctic Circle don't have to worry
about getting the airframe too hot.
Best regards,
Rob Housman
Irvine, California
Europa XS Tri-Gear
S/N A070
Airframe complete
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of
DuaneFamly@aol.com
Sent: Thursday, July 19, 2007 3:23 PM
To: europa-list@matronics.com
Subject: Re: Europa-List: Europa rules
Raimo,
Congratulations to you and your aircraft. I think we can all stand a
little taller and more proud when one of "our" planes tops the list of
all in an entire country.
Do you have any pix of you panel? Is the underside of your aircraft
really painted dark? Black, blue, brown? Any reasoning for this?
Mike Duane A207A
Redding, California
XS Conventional Gear
Jabiru 3300
Sensenich R64Z N
Ground Adjustable Prop
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