This might work as the opposite, which is a zinc grid as part of the highway to reduce rebar corrosion has been featured at civil engineering magazines
electrical contact with a slightly damp or moist road is sufficient to create anodic protection with time
the zinc plus hygroscopic (auto moistening) dragline would corrode rather than vehicle chassis metal
It might be a cheap or complementary strategy to "undercoating"
I had the idea when a person at yahoo answers wanted a cheap thing they could make n vend as rather like a girl scouting project
this might have hundreds of millions of application points, actually be useful, n be girl scout troop buildable-- beanangel, Mar 09 2008 Actually, [treon], this might not be such a stupid idea. Better, perhaps, to have zinc wires embedded in the tyres, which would wear with the tread. Or perhaps applying the handbrake would lower a zinc plate onto the road surface, preserving the car whilst parked, at least.
I'm not sure if it would be able to protect girl scouts from corrosive influences, though.-- MaxwellBuchanan, Mar 09 2008 I can remember a time when it was customary to fit a chain, that dangling under your car, and made intermittent contact with the road as you drove along.-- xenzag, Mar 09 2008 Why not just galvanize the monocoque? Oh right, car makers want to sell more (replacement) cars.-- Texticle, Mar 09 2008 //fit a chain, that dangling under your car//
I think that's to prevent static electricity from building up-- FlyingToaster, Mar 10 2008 I am going to bun this idea, but not before I do the following:
sp: and sp: and sp: and sp: and sp: and-- moomintroll, Mar 10 2008 This is widely baked by individuals, including me, but has strangely never become a mainstream product. It does not need to touch the ground, you just attach a block to an uncoated part of the chassis.
The problem with this system is that electrons will prefer to travel a short distance than seek out the zinc that is thousands of times further away.
A better way is to run a current through the chassis, which I believe is why the chassis forms part of the circuit from the battery to headlights, etc.-- marklar, Mar 10 2008 Cars are generally safe from lightning because the tires insulate them from contact with the road; this idea would make them into lightning rods.
Many newer cars now have plastic or composite body panels. This trend in manufacturing will likely expand, as consumers demand lighter, more fuel-efficient vehicles. Incidentally, it reduces corrosion.
However, if cars never corroded, consumers wouldn't have to replace them every few years, manufacturers would produce less, and the cost per unit would probably double or triple.
I personally like the idea of a powder-coated, aluminum spaceframe chassis covered by composite outer panels that could be replaced from time to time to freshen the appearance, or to alter the configuration, such as the 1994 Mercedes VRC concept.-- whlanteigne, Mar 11 2008 //safe from lightning because the tires insulate them// No; cars are safe for the occupants because the chassis acts as a Faraday cage, directing the charge around the outside and leaving the cavity safe.-- neutrinos_shadow, Mar 11 2008 itd be nifty to do a test on junkyard cars-- beanangel, Mar 11 2008 //manufacturers would produce less, and the cost per unit would probably double or triple//
Would love to see some stats. to support numbers anywhere near your supposition.-- sprogga, Mar 11 2008 If cars didn't corrode their internals would still wear out, despite carmakers attempts at extending their purposeful life 5-6 times as long as they used to last.
We are not conspirators plotting to prevent the masses from acquiring technology for the benefit of mankind. Sorry to burst your conspiracy theory.
The costs to produce the first prototype handbuilt mule vehicle run into territory of $750,000 or so. We build hundreds of prototypes at varying levels of prices for testing, crash, and development purposes. The tooling to build the car parts costs several hundred million dollars typically, depending on the size and scope of the vehicle program, perhaps a $billion or maybe two. For the whole program, including labor, materials, tooling, health insurance, part shipping costs and dunnage, factory startup and such, double that again and add some more. Throw in vehicle variants of differing powertrains, configurations, paint schemes, colors, trim levels, etc and the bill just went up again. Make significant numbers of goofs or changes, and pay again.
When you're talking about new powertrains, the numbers are even worse, as the sunk costs must pay themselves back over at least a decade in volumes of millions of units. It is the realities of these investments which slows down the rate of scientific progress to a large degree.
With an average selling price of a vehicle at, say roughly $30,000, the vehicle must sell at least 130,000 units just to break even. These are the current realities of large scale manufacturing, which the general public is shielded from by the ability of manufacturers to make the business case work. This is why smaller-volume cars are almost always luxury/performance models unless they share a common platform. Shrinking those numbers is the continuous holy grail of automotive engineering.-- RayfordSteele, Mar 11 2008 The next question, then, is how do the kit car companies survive? I guess the answer is that they use existing suspension, engines, gearboxes, and eschew OEM-grade refinement for a more unique experience?
/attempts at extending their purposeful life 5-6 times as long as they used to last/
I thought that was my job as the owner of an older small car?-- david_scothern, Mar 11 2008 [RayfordSteele], why aren't steel cars galvanised?-- Texticle, Mar 11 2008 while I was visiting the county correctional facility on refusing a jaywalking ticket (the cops were accurate n fair on that) I had the opportunity to view the metal a car was made from; the sheet metal had at least a 3mm error; I was thrilled, my afternoon went with figuring out how to rescue ford from its less than 2 pt margin per vehicle based on simultaneous manufacture of the metal parts; you could possibly have just a third as many customized sheet metal fabrication stations then make them like cheese shapes with a press; with the right velocity profile n software the dimensional tolerance variances neutralize to create functionality
I guess the rapid version to the carmakers would be: are there multifactor measuring computer vision systems that can match tolerance variant parts to create a tolerance compliant subassembly; if there are you can go cheap on the metal press
upping the margins a few pt the big bonus is a third of the machinery cost to produce the sheet metal components of vehicles "rescuing" an automaker-- beanangel, Mar 11 2008 I'm assuming "pt" should be read as "percent," which is abbreviated "pct." I've got a lot of print shop experience, so I keep seeing "point." You're killing me.
This is baked - there've been anodic protection systems on the market for years. They go somewhere on the chassis. The dragging chain you're talking about was to prevent static build-up. I haven't seen a car dragging a chain in a long, long time - pretty much not since I last saw a body-on-frame Pontiac LeMans.-- elhigh, Mar 12 2008 Dragging an anode on the ground is only useful if it is in the galvanic circuit - for example, you always park/drive in water deep enough to contact the body. Otherwise, the circuit is just within the body, as noted by [marklar].
I still see dragging static chains on vehicles quite often - especially school buses.-- lurch, Mar 12 2008 Galvanization is not a perfect cure-all. Clear coating is generally superior to it for areas where the paint is applied.
I'm no materials expert, but some issues I could see with galvanizing in the factory would be the environmental hazard of fumes, difficulty in welding after galvanization and difficult or impossible access to certain panels in an assembly environment. There are probably other reasons.
Treon, there are several problems with match-mounting body panels, (match-mounting is sometimes done in high-precision components, like bearings or precision-balanced fast rotating assemblies, like driveshaft assemblies). First is the speed at which they are required to be assembled, which requires the parts to be sequenced for robotic loading and unloading. I could see perhaps an offline station at which panels might be sorted by tolerance, but the costs would outweigh the benefits. Second would be the fact that for any given panel there are several interfaces; matching interfaces in one joint would likely drive others out of kilter. And thirdly, its generally not so much differences in stamping sizes but welding precision which becomes the issue.
The tolerances you witnessed were likely a stackup of several interfaces, each which have their own tolerances in assembly, although in my experience Ford's problem has been its old facilities, primarily.-- RayfordSteele, Mar 12 2008 random, halfbakery