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> One area that's crying out for super-lightweight paints is the aviation sector. Airliners, according to Simple Flying, carry between 272-544 kg )600-1,200 lb)
by throwup238 3y ago
> One area that's crying out for super-lightweight paints is the aviation sector. Airliners, according to Simple Flying, carry between 272-544 kg )600-1,200 lb) of paint – and everything an aircraft carries has a direct impact on fuel efficiency.
The vast majority of that weight is in the white paint on the body of the plane, which has to be thick because of mechanical abrasion in flight so that weight is largely unavoidable.
- carterschonwald 3y agoCould you expand on this?
- bagels 3y agoFlying a jet at 600 mph through dusty air is abrasive. The paint protects the aluminum from corrosion and abrasion. If chemical and mechanical barrier is too thin, the metal will become damaged.
- deleted 3y ago[deleted]
- Aqua_Geek 3y agoDo airlines that have a “bare metal” livery still coat the planes with something, then? (I assume there’s a clear coat.) Does that weigh less than white paint?
- NegativeLatency 3y agoDoes anyone still do that? American Airlines has a white base now.
- hiharryhere 3y agoAmerican stopped because the new composite planes like the 787 aren’t metal any more.
- ethbr1 3y agoI'd assume the alternative is probably the same weight as paint, as the bulk of the paint mass is likely the protective polyurethane/whatever. Or to put it another way, does clear paint weigh less than colored?
- dylan604 3y agoPigment does have weight. I'm not sure of anything useful that has no mass.
- crazygringo 3y agoNo, there is no clear coating. It's bare metal that gets polished: > The metallic fuselage skin of modern airplanes is made of alclad aluminum alloy. The word “alclad” means a thin layer of pure aluminum is applied over the entire aluminum alloy fuselage skin, generally a variant of 2024 alloy, at manufacture. This pure aluminum layer almost immediately turns into aluminum oxide: and then begins its magic. A bit of polish applied periodically keeps the pure aluminum layer at a silver shine, otherwise it grows dull — but still continues to protect. https://www.quora.com/Why-did-American-Airlines-stop-painting-their-planes-silver-any-other-reasons-beside-the-reflection/answer/Krishna-Kumar-Subramanian?ch=15&oid=85476656&share=2fc4fffe&srid=3AY&target_type=answer https://www.quora.com/Why-did-American-Airlines-stop-paintin...
- JoshTriplett 3y agoTo what extent would it be possible to trade off between that and more abrasion-resistant materials? Are there materials with a comparable or higher strength-to-weigh ratio that have less tendency to gradually ablate in 600mph air/dust/rain/etc? (Are there materials that would work better but cost more, and aluminum-with-thick-paint is a cost tradeoff?) For clarity: I'm sure that aeronautics engineers have thought extensively about that question, and while it's possible that a small fraction of the answer is "we've always done it this way" and there might exist better alternatives, my expectation on balance is of learning the reasons why it's done this way.
- deleted 3y ago[deleted]
- mdorazio 3y agoNot really. AA left their planes unpainted for decades and they were fine because aluminum is naturally corrosion resistant through the formation of aluminum oxide. However, the aluminum dulls and needs to be polished regularly to not look like shit. Also, the composite surfaces need to be painted to avoid UV damage, so most airlines just paint everything anyway.
- userbinator 3y agoAlso, "hundreds of kilograms" is not a lot if you consider how much the rest of the plane weighs --- a 737 MAX is ~100k lbs empty, so this is less than 1% of its empty weight, and a 747 is between 300-500k lbs empty. Then again, given how airlines would cram in even 1 more passenger if they could, and the absolute minimum robustness of other mechanisms on a plane as a result of weight-saving, I think they will still chase after <1% gains.
- fbdab103 3y agoI would think that modern planes are more constrained by volume than weight.
- dahfizz 3y agoNot "constrained" really, but every pound you put up in the air costs fuel. Making the plane lighter immediately saves money.
- arcticbull 3y ago> ... and the absolute minimum robustness of other mechanisms on a plane as a result of weight-saving ... Being on a plane is the single safest place you could possible be at any time as a human.
- thewakalix 3y agoDo you have a source for that?
- arcticbull 3y agoGlobal passenger volume in 2023 was about 8.6 billion, anticipated to be 9.4 billion in 2024. Total, global death count due to accident fatalities is measured in the hundreds. Usually 100-500 per year. Global accidents per million departures usually hovers around 2, and that's not fatal accidents, which are about an order of magnitude less frequent. Here's the 2023 ICAO safety report. [1] [1] https://www.icao.int/safety/Documents/ICAO_SR_2023_20230823.pdf https://www.icao.int/safety/Documents/ICAO_SR_2023_20230823....
- m463 3y agorelated, I wonder how much tesla is saving with the cybertruck.