Ever wonder why trucks have those quilted rear doors?

Originally published at: Ever wonder why trucks have those quilted rear doors? | Boing Boing

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paint would add weight, right? bad for fuel consumption.

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Since all of the non-diamond style doors don’t utterly blind us, I assume that whatever those use (paint, transfer/sign stickers/etc.) are just as useful. Now if it was totally chrome, it might be blinding (and sorta badass).

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I always thought it was to stiffen the metal so that they could use thinner sheets.

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For the tailgaters who insist on using their high beams, aluminum diamond plate on the back of the toy hauler/trailer/tailgate does wonders to curb this behavior.

Note: This may bruise the egos of certain highway patrol officers who want to use their lighting package to the fullest extent possible. YMMV.

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Paint wouldn’t add a lot of weight (~1 lb)… but even white paint would absorb sunlight and get hotter than a reflective finish. That’s especially important if you’ve got a refrigerated trailer.

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Paint also comes off and needs to be repainted from time to time.

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I took some long road trips as well as had a job that sometimes required me drive long distances. I loved driving behind tanker trucks with a mirror polish back plate. I was stuck behind one for hours once in the desert, as we slowly drove along a highway that for some reason that I can’t remember was packed. That distorted view, near fisheye, kept me focused and it was such beautiful land.

Also I always thought those quilted doors, were on one brand of insulated trailer.

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I know a few folks who have been dinged by the small town cop tactic of brights + tailgating to get you to speed so they can write you a ticket. Middle aged barney fife type cops.

God bless. I suffer from light-sensitive migraines, and 50% of the time, it’s reflected glare off of cars.

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It’s not even that: When water collects beneath paint (especially due to cracks in the paint), it has the annoying tendency to cause the paint to peel faster (think freeze and thaw) and the metal to corrode faster. Also, peeling paint is aesthetically less appealing than bare metal, and has to be repainted.

Am pretty sure it’s this - in combination with the fact that it’s practically impossible to keep unbiased thin sheets truly flat and whatever arbitrary warp-age they take on would appear less-than-correct. Once did some work in a shop that had the machine for pressing this pattern on panels on food trucks (interior and exterior), it was basically two large roller drums surfaced with hardened steel dies in the positive of the pattern.

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I’m thinking still what do you really want to do when the sun is setting right in front of you and you can’t see a single thing…

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That “casting shade but only around the eyes” effect is basically the opposite of how they lit Angelica Huston for the Addams Family movies.

morticia

joan juliet buck was infamously friends with the angelica woman…

Imgur

I agree the weight of the paint might not be substantial, but it’s probably more than 1 lb. A web search tells me that to paint the hood of a typical passenger car, you’d need about 240 mL of primer, 360 mL of color, and 600 mL of clear coat for a total of 960 mL. Google says automotive paint weight approximately 3 pounds per liter. I would guess that the surface area of the rear doors is between two and five times that of the hood of a car. Even if you substitute a second coat of color for the clear coat, you’re still probably closer to 10 lbs than 1 lb.

It’s true that paint would reflect slightly less light than the bare metal, but there’s no reason why the door has to be polished to a mirror-like chrome finish. A scuffed up metal surface, like brushed metal, would reflect the same amount of light, but in a more diffuse pattern.

My response to over-bright headlights, either badly adjusted dips or just some jackass who can’t be bothered to dip his mains was either just use the little lever under my rear view mirror, or angle it to reflect back at the driver.
My latest car has an auto-dimming mirror, which along with the heated screen, CarPlay and a reversing camera has made me really appreciate the advances in motoring technologies: it’s quite a long way from my previous 19 year old Skoda Octavia!

That’s fascinating, it’s exactly the technology I’ve been thinking of when driving towards a low setting sun, and it also rather reminds me of similar tech described by Larry Niven in some of his books, a spacesuit visor that could put a black spot onto the visor to block a very bright star, but still allow a clear view of surrounding space.
One of the most dangerous roads in the U.K. is the M4 motorway, which runs just north of where I live. It goes east to west between London and Wales, and you have the sun directly in your face morning and evening, depending on direction of travel, and a sun visor is useless once the sun is below the bottom edge, especially if the road is wet and there’s lots of spray, it becomes very challenging, car brake lights and indicators become really difficult to see clearly.

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it’s about the only thing elon musk has not done anything about yet…

Well technically assuming that the surface is not a lack body (a fair assumption), at steady state all surfaces reflect the same light. But all reflected light will adhere to a bi-directional reflectance distribution function (BRDF) specific to the surface. With a rough surface there is a large component reflected back in the direction of the incident beam, lessening the amount of light scattered forward and thereby less annoying to the observer. For a highly reflective surface the light that is reflected back to the incident ray is negligible so the forward reflection is higher. There’s also some lateral scattering (which is why it is a bi-directional function) but this not as noticeable (and the math is kinda squirrelly).
G41cH

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