What is the best way to protect bare iron metal from rust? Options

[Langing]

I picked off a steering knuckle from a junkyard Celica, removed the ball joint and wheel bearing, and cleaned it with a wire wheel to the point where it seems rust and yuck free. Now it is almost all bare metal and I have two questions:

1) What is the best/easiest way to remove the remaining rust? (I don't have a sand blaster.)

2) What is a good/long-lasting way to protect the bare metal from rusting again?

To show what I am talking about I include a photo of the newly cleaned SN next to my Celica's SN (the one with with bent ears). The junkyard SN is the lighter of the two, the golden rust colored one; it came from a red 1995 Celica and is going on a white 1994 Celica:



Thanks to anyone who takes time to help me by discussing these questions.

[Special_Edy]

I never understood how people can believe that lightning can jump miles from the ground to a cloud, but somehow 3 inches of rubber will stop it. Wont it just jump the 6 inch gap from your undercarriage to the ground, since it just jumped 63,360 inches to the cloud (supposing one mile). I dont think its because the car is a faraday cage, I think that has to do with electromagnetic radiation. Faraday cages are used to shield electronic devices from electromagnetic interference or even an EMP. If your car was a faraday cage your cellphone would be unable to recieve a signal inside it for example. The skin of the car is 1000s of times more conductive than its occupants or the air space inside, so naturally the electricity takes the path of least resistance. If it can jump through air, your car is a cakewalk. They say airplanes are struck by lightning extremely often, but no damage occurs due to the airplane's conductive skin.

The ground straps you see on cars are for static electricity. They are often required on airport vehicles. I think it is due to the static charge which builds on planes from them traveling through the air at high speeds. Your fuel tank filler hose is actually constructed of a specialized type of rubber and often grounded, the simple act of gas pouring through when you fill the tank would generate enough static charge to ignite the gasoline if it was regular rubber.

You dont need antisieze, probably the #1 time its recommended is different alloys of metal threading together, like a steel spark plug into an aluminum head. You can use just about any lubricant other than water as an anti seize. I prefer some used oil from my last oil change.

This post has been edited by Special_Edy: Jun 20, 2014 - 11:05 PM

[Langing]

I never understood how people can believe that lightning can jump miles from the ground to a cloud, but somehow 3 inches of rubber will stop it. Wont it just jump the 6 inch gap from your undercarriage to the ground, since it just jumped 63,360 inches to the cloud (supposing one mile). I dont think its because the car is a faraday cage, I think that has to do with electromagnetic radiation. Faraday cages are used to shield electronic devices from electromagnetic interference or even an EMP. If your car was a faraday cage your cellphone would be unable to recieve a signal inside it for example. The skin of the car is 1000s of times more conductive than its occupants or the air space inside, so naturally the electricity takes the path of least resistance. If it can jump through air, your car is a cakewalk. They say airplanes are struck by lightning extremely often, but no damage occurs due to the airplane's conductive skin.

The ground straps you see on cars are for static electricity. They are often required on airport vehicles. I think it is due to the static charge which builds on planes from them traveling through the air at high speeds. Your fuel tank filler hose is actually constructed of a specialized type of rubber and often grounded, the simple act of gas pouring through when you fill the tank would generate enough static charge to ignite the gasoline if it was regular rubber.

You dont need antisieze, probably the #1 time its recommended is different alloys of metal threading together, like a steel spark plug into an aluminum head. You can use just about any lubricant other than water as an anti seize. I prefer some used oil from my last oil change.

I think you have the idea of a Faraday Cage down pretty well. I remember laboratory rooms set up that way so they could study instruments without any possible interference from EMR, and yes, EMP. Some were made of copper mesh wire and parts of solid copper, even the doors were special because they had to be an integral conductor tied into the rest of the conducting metal surround once you closed yourself inside. You are right, their intent was to protect the inner environment from as many frequencies of electromagnetic radiation as needed. The higher the frequencies you wanted to keep out, the finer the wire mesh, because they have shorter wavelengths. Take that to the limit and you have a solid metal sphere.

You can use your iPhone in your car because your car isn't exactly the same degree of a Faraday Cage; think of it like a "partial" or "incomplete" Faraday Cage maybe, or a cage with a very coarse wire mesh (the laboratory versions used fine wire mesh, finer than the screens on your windows, so the openings were very small), where there are ports, or openings (the front, side, and rear windows, at the least) that permit some electromagnetic waves to get in or get out, but whatever EM radiation that impinges on the metal surfaces does, indeed, travel along its skin to ground, it there was a grounding strap from the undercarriage.

When it comes to a lightening bolt, the phenomenon is not so much electromagnetic radiation as it is the actual movement of electric charge (which produces electromagnetic radiation, of course). In this case the electrons moving through the air just love it when they come in contact with metal, because metals are excellent conductors of electrons (the path of least resistance). And remember that the initiation phase of a lightening strike first produces tons of soon to be aborted streamers (only one actual conductive pathway ever completely forms), little jets of emitted electrons jumping off the ground into the air all over the place.

Imagine your car way out on the salt flats of Utah, with nothing for miles around that is any higher than the top of your car. Should a thunderstorm rumble through, and pass directly overhead, you would likely be struck with lightening because one of those initial streamers would leap from ground (earth) to the metal of your car (the air gap is insignificant to lightening because of the gigantic voltage differences) and very rapidly travel through the metals of your car up to its topmost part, and the number of electrons up on top would just as rapidly build up until it had enough opposite charge to be able to attract the electrons in the thunder cloud to be directed straight to it. Then ZAP! Another metaphor -- a golfer on an flat fairway holding his club in the air!

But you wouldn't necessarily notice anything electrically shocking, except the brilliant flash and the unbelievably loud thunderclap that would immediately follow since the lightning (ELECTRIC CURRENT) struck directly on your car, so close that the light and sound produced by the ionization of the air come at you senses almost simultaneously! All that electric charge is being discharged in an instant. The reason I called your car a Faraday Cage was that it is a relatively large percentage of a complete enclosure by metal, which thus protects the insides from this kind of an electrical discharge (CURRENT) being passed directly through the inner space, especially the (conductive) people inside, from having the deadly lightning bolt travel straight through their bodies in its desperate attempt to get to ground. Instead, since your vehicle has a lot of metal in its makeup, the current travels along the metal pathway.

And, once the conductive pathway has established the actual path (from among the many that initially tried to form) the electricity will continue to flow through the actual path (ionized air and metal combined) until the charge in the cloud has been totally discharged. That's why you can actually see a lightening bolt; it's a dramatic flow of electric charge all passing through the same basic path.