5 ms·

What happens when they paint the parts to prevent corrosion? I imagine all the properties of the laser etching are negated.

deleted 7y ago
[deleted]
kilo_bravo_3 7y ago
I imagine this technique would be most useful on the leading edge of wings and the engine nose cowlings. On many aircraft those parts are left unpainted anyways.
- WalterBright 7y ago
  > On many aircraft those parts are left unpainted anyways. Erosion will de-paint it anyway.
oliveshell 7y ago
As far as I understand it, corrosion isn’t that much of a worry with aluminum airframes— as long as the plane doesn’t spend too much time near salt water. There are many past and present airline liveries where the fuselage is left largely bare, for instance: https://upload.wikimedia.org/wikipedia/commons/5/5f/Boeing_767-323-ER%2C_Oneworld_%28American_Airlines%29_AN2217029.jpg https://upload.wikimedia.org/wikipedia/commons/5/5f/Boeing_7...
- oliveshell 7y ago
  To the person who downvoted the above without leaving a comment: Is this not the case? I know for a fact that planes whose home airport is near the ocean have more issues with corrosion. If I'm wrong, I'd be genuinely delighted to learn how.
  - 0_____0 7y ago
    didnt downvote you but your link is broken (lost 'g' at the end)
    - oliveshell 7y ago
      Whoops! Fixed, thanks.
  - numpad0 7y ago
    So everyone knows that aluminum develops a chemically stable oxidation layer that prevents ionization, or something like that. In reality though, that layer shows zero mechanical strength. You don’t see that with aluminum products but only because they are always anodized. Without anodization or just left in the wild, aluminum develops white salt like corrosion on its skin. I have anecdotal experience of this with a PowerMac G5. It was a school computer, I got to see inside, and years later I found fingerprints of my younger self permanently engraved on it.
    - handedness 7y ago
      That layer also doesn't shine, something people don't take into account. A local FBO with a fleet of gorgeous airframes polishes them at a minimum of monthly, and they don't fly more than about once a month. Polished aluminum is labor-intensive to keep looking good. But I'm glad so many still take the time to do so.
- metaphor 7y ago
  Just because it looks bare doesn't mean it's unfinished. If I specified sheet aluminum for Type II Class 3 chemical conversion per MIL-DTL-5541, any materials QC professional would be hard pressed to visually determine that anything was actually done to the material. To be sure, no, MIL-DTL-5541 isn't an uncommon spec constrained to military applications.
  - 0_____0 7y ago
    any idea what they use on aircraft skins?
    - metaphor 7y ago
      That's not an application you can generalize. Literally everything is dependent on requirements.
  - hinkley 7y ago
    I know I've noticed on airplanes before that while some of the wing is aluminum colored, some areas in particular are painted a vaguely aluminum-colored shade of grey. And I think the... it seems they're called Krueger flaps? Those are often painted aren't they? And those I'd think you'd definitely want to de-ice.
    - handedness 7y ago
      On an aircraft that has a mixture of polished and painted surfaces, the painted surfaces often aren't bare aluminum. Often that's the wing root fairings, winglets, nacelles, radar cones, vertical stabilizer, and so on.
      - hinkley 7y ago
        I don’t think I was meant to get a giggle out of this. Can you explain using other words? Of course a painted surface isn’t bare. It’s got paint on it. Did you mean it’s not aluminum? Or a different grade?
- WalterBright 7y ago
  > corrosion isn’t that much of a worry with aluminum airframes The internal aluminum components are all finished with BMS 10-11 Type 2 primer (the ubiquitous green stuff). (Amazing what trivia I remember from 40 years ago!)
- tyingq 7y ago
  If you don't paint it, you have to polish it periodically, which is more expensive. A pre-pitted surface probably more so.
- angry_octet 7y ago
  Planes that are freshly painted are 'slick' -- they have noticeably less drag! A good paint coating also makes it easier to wash dirt and other contaminants, which cause drag and corrosion. Corrosion is indeed a problem, but only severely for salty places. Paints also have UV screen for plastic composite components.
bdamm 7y ago
I'm betting this becomes a paint job option. While it looks appealing I also can't help but suspect real world will just fill those crevices up with bug guts pretty quick.
frandroid 7y ago
Maybe it could be combined with this technique so the aircraft body can be laser-etched for both colour and anti-icing: https://www.rochester.edu/news/show.php?id=3106 https://www.rochester.edu/news/show.php?id=3106
LifeLiverTransp 7y ago
You could just laser etch not the metal, but the paint of the finnish..

deleted 7y ago

[deleted]

kilo_bravo_3 7y ago

I imagine this technique would be most useful on the leading edge of wings and the engine nose cowlings. On many aircraft those parts are left unpainted anyways.

WalterBright 7y ago
> On many aircraft those parts are left unpainted anyways. Erosion will de-paint it anyway.

oliveshell 7y ago

As far as I understand it, corrosion isn’t that much of a worry with aluminum airframes— as long as the plane doesn’t spend too much time near salt water. There are many past and present airline liveries where the fuselage is left largely bare, for instance: https://upload.wikimedia.org/wikipedia/commons/5/5f/Boeing_767-323-ER%2C_Oneworld_%28American_Airlines%29_AN2217029.jpg https://upload.wikimedia.org/wikipedia/commons/5/5f/Boeing_7...

oliveshell 7y ago
To the person who downvoted the above without leaving a comment: Is this not the case? I know for a fact that planes whose home airport is near the ocean have more issues with corrosion. If I'm wrong, I'd be genuinely delighted to learn how.
- 0_____0 7y ago
  didnt downvote you but your link is broken (lost 'g' at the end)
  - oliveshell 7y ago
    Whoops! Fixed, thanks.
- numpad0 7y ago
  So everyone knows that aluminum develops a chemically stable oxidation layer that prevents ionization, or something like that. In reality though, that layer shows zero mechanical strength. You don’t see that with aluminum products but only because they are always anodized. Without anodization or just left in the wild, aluminum develops white salt like corrosion on its skin. I have anecdotal experience of this with a PowerMac G5. It was a school computer, I got to see inside, and years later I found fingerprints of my younger self permanently engraved on it.
  - handedness 7y ago
    That layer also doesn't shine, something people don't take into account. A local FBO with a fleet of gorgeous airframes polishes them at a minimum of monthly, and they don't fly more than about once a month. Polished aluminum is labor-intensive to keep looking good. But I'm glad so many still take the time to do so.
metaphor 7y ago
Just because it looks bare doesn't mean it's unfinished. If I specified sheet aluminum for Type II Class 3 chemical conversion per MIL-DTL-5541, any materials QC professional would be hard pressed to visually determine that anything was actually done to the material. To be sure, no, MIL-DTL-5541 isn't an uncommon spec constrained to military applications.
- 0_____0 7y ago
  any idea what they use on aircraft skins?
  - metaphor 7y ago
    That's not an application you can generalize. Literally everything is dependent on requirements.
- hinkley 7y ago
  I know I've noticed on airplanes before that while some of the wing is aluminum colored, some areas in particular are painted a vaguely aluminum-colored shade of grey. And I think the... it seems they're called Krueger flaps? Those are often painted aren't they? And those I'd think you'd definitely want to de-ice.
  - handedness 7y ago
    On an aircraft that has a mixture of polished and painted surfaces, the painted surfaces often aren't bare aluminum. Often that's the wing root fairings, winglets, nacelles, radar cones, vertical stabilizer, and so on.
    - hinkley 7y ago
      I don’t think I was meant to get a giggle out of this. Can you explain using other words? Of course a painted surface isn’t bare. It’s got paint on it. Did you mean it’s not aluminum? Or a different grade?
WalterBright 7y ago
> corrosion isn’t that much of a worry with aluminum airframes The internal aluminum components are all finished with BMS 10-11 Type 2 primer (the ubiquitous green stuff). (Amazing what trivia I remember from 40 years ago!)
tyingq 7y ago
If you don't paint it, you have to polish it periodically, which is more expensive. A pre-pitted surface probably more so.
angry_octet 7y ago
Planes that are freshly painted are 'slick' -- they have noticeably less drag! A good paint coating also makes it easier to wash dirt and other contaminants, which cause drag and corrosion. Corrosion is indeed a problem, but only severely for salty places. Paints also have UV screen for plastic composite components.

bdamm 7y ago

I'm betting this becomes a paint job option. While it looks appealing I also can't help but suspect real world will just fill those crevices up with bug guts pretty quick.

frandroid 7y ago

Maybe it could be combined with this technique so the aircraft body can be laser-etched for both colour and anti-icing: https://www.rochester.edu/news/show.php?id=3106 https://www.rochester.edu/news/show.php?id=3106

LifeLiverTransp 7y ago

You could just laser etch not the metal, but the paint of the finnish..