Paint color temps.....

Discussion in 'Finishing Techniques' started by MadProfessor8138, Dec 24, 2018.

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  1. Dec 24, 2018 #1

    MadProfessor8138

    MadProfessor8138

    MadProfessor8138

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    If this question has been asked before I apologize but I couldn't find a thread on this particular subject.....
    So I've been sketching out paint schemes for my RW19 Stork well in advance of its completion and I have a question about paint colors that I cant seem to find an answer to.
    It is a wooden aircraft that will be painted with latex paint and will have a lot of graphic designs in the scheme...think graffiti artist.
    I know a dark color like black, olive drab,dark blue,etc. should be avoided due to interior temps. but what about florescent colors such as green,purple,blue,orange etc.
    Will these florescent colors heat up like a dark color will ?
    Yes they are somewhat dark colors but they are florescent and will be a gloss finish that should reflect the light instead of obsorbing the uv rays and heating up the interior of the aircraft.
    Anyone have an opinion on color temps. ????
    I really dont want to be stuck with plain ole drab white with some trim.......ugh.

    Kevin
     
  2. Dec 24, 2018 #2

    TFF

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    A wood aircraft should not have any problems with any color. Wood acts as an insulator, if you are worrying about softening epoxy. Different if talking composite; the epoxy is in direct contact with the paint there. Now I knew someone with a crazy colored Storch and it just looked odd.
     
  3. Dec 24, 2018 #3

    MadProfessor8138

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    The epoxy softening issue is the exact reason I'm asking about paint colors and the temps. that they might generate on the interior of the plane.
    T88 has a maximum service temp. of 160° F and then it breaks down.
    That sounds like an unobtainable degree of heat but it's really not.
    Dark colored objects setting in direct sunlight can have temps. that skyrocket the thermometer.....think how hot your car gets setting in the sun during the summer,leather seats can literally cook the hyde off your backside.
    I've often wondered what the temps. on the inside of wings and fuselages were on dark colored aircraft in the sun.

    I actually know a couple of guys that do graffiti as a hobby and they do beautiful work.....its truly a talent and skill that they posses.
    I will probably turn them loose on the plane after approving their sketches.
    Most of the Platus Porters have wild paint designs and they look pretty cool..........so why not.......sure beats white with trim stripes.

    Kevin
     
  4. Dec 24, 2018 #4

    choppergirl

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    From this thread: https://www.homebuiltairplanes.com/forums/showthread.php?t=27959

    [​IMG]

    Dayglo florescent colors will absorb some of the other light wave lengths, and re-emit that energy on the target color wavelength... therefore, theoretically, a little less energy stays on the wing surface, and perhaps less heat, if you are using a truly florescent paint. Materials also absorb wavelengths beyond the visible spectrum... if you put something near an infrared or ultraviolet lamp or microwave oven emitter or radar dish... it gets hot. So... not only about reflecting wavelengths within the visible spectrum.

    The SR-71 got raging hot, and yet they still painted it some radar absorbing black mixture, so, go figure. On the other hand, it was made out of Russian titanium.
     
    Last edited: Dec 24, 2018
  5. Dec 24, 2018 #5

    lr27

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    I've measured 140 F inside an old Honda Accord on a warm sunny day at 42deg N lattitude. Just enough to soften an epoxy glass over foam model wing enough to straighten it. It was probably WEST epoxy. Maybe a cockpit would reach the same temperature. I imagine it might get a little hotter in Kentucky. I don't have any figures for painted surfaces, but I'm sure someone does.

    I'm wondering if T88 isn't a little more heat resistant after sitting around at, say, 90 or 100 F for a while.
     
  6. Dec 24, 2018 #6

    pictsidhe

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    I'm in the UK with a colour card for Sherwin Williams 'vinylsafe' paint I hope to get a close-ish match to WWII RAF colours. It's paint that doesn't get as hot as paint its colour usually does but is way cheaper than most cool paint. I'll buy and test some next year.
    Pallete is rather limited, but does give us some new options.
     
  7. Dec 24, 2018 #7

    Mad MAC

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    I recall reading an Ozzie test report on maximum internal temperature of wooden wings (Anson I think) they got a maximum internal temp in the region of mid 60's deg C (details a bit vague was only 20 years ago I read it).
     
  8. Dec 24, 2018 #8

    TFF

    TFF

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    I'm sure your friends can do a great job. This one was stuffed in a hangar across from me for years. https://m.youtube.com/watch?v=GI_6m2GWX-A not pretty. Just me but I got room for a tail gunner I don't want to waiste the chance.
     
  9. Dec 24, 2018 #9

    MadProfessor8138

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    I've seen that plane before,while I'm not crazy about the design of the paint scheme,I do like the contrast of colors.
    I've never understood why someone spends years of their time and a big chunk of their finances to just paint the plane a solid color with a stripe.....ugh.
     
  10. Dec 24, 2018 #10

    MadProfessor8138

    MadProfessor8138

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    The SR71 is a totally different beast from any aircraft that may role out of a private shop.
    The black paint only served one purpose and that was to absorb radar waves in an early attempt of stealth technology.
    Whatever color that provided stealth is what the aircraft got painted,thankfully it didnt turn out to look like a float in a gay pride parade for the rainbow coalition....just saying.
    The temps. that the skin of the aircraft reach is in excess of 600°F but that is due to the friction of the air moving across the skin and not the color.
    When the plane was being developed the engineers accounted for this and did two things to overcome the issue.....first it was built out of titanium to take the heat,second it was built with very wide tolerances between the joints....you can actually measure 1/4" - 3/8" gaps between panels when it is cool.
    The thing leaks fuel ike a syve until it's up to speed and heats up,expanding the skin and sealing the gaps.
    It has to refuel after takeoff due to fuel loss on the ground.

    One funny fact about paint is that there are many people that will argue to never use latex paint on an aircraft and that it only belongs on houses.
    Well,houses set in the elements 24/7 and the latex paint holds up just fine for 20,30,40 years.
    Anybody want to guess what the SR71's got painted with when they were retired and parked out in elements ?
    They found it to be the only paint that would stand up to the weather.......
    Any guesses ????????

    Kevin
     
  11. Dec 24, 2018 #11

    lr27

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    The paint they use on cars these days holds up to the weather pretty well, too. So I don't think it's a foregone conclusion that they'd use house paint. One might argue that houses don't usually flex the way fabric does, but of course we have examples of airplanes painted with latex that do ok.
     
  12. Dec 24, 2018 #12

    blane.c

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    According to AC 43.13-1B on page 1-36 of my copy, section 1-68, a partial quote "Wood loses approximately 25% of it's strength at 125*F. For this reason the mechanic should consider temperature effects when selecting finishing colors or looking for areas of likely deterioration."
     
  13. Dec 24, 2018 #13

    TFF

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    Solid color and a stripe= six months less taping and painting. I did five color flames once on a car; looked great; what a pain. If you can cheat and give the pain to someone else, go for it.
     

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