Salvaged goodies rusting away

[kolechovski]

I have a question for anybody who has colelcted general track objects like tie plates and spikes and stuff.  I had salvaged, with permission, a bunch of these things that otherwise would have simply been wasted (it's surprising railroads don't recycle iron scraps like this).  I noticed somthing odd while it was sitting at my house over a few months.  As I have been busy, I have not had the time to scrape off the old rust and shine up these objects I have collected.  While they've been sitting in a pile, I've noticed that over this little time, everything, including the objects (spikes for example) that had a good polish were rusting heavily, with a reddish color.  This is odd, as these objects had been exposed to the elements at their old location for many many months, and they have not suffered anything near what they have in the short time I had them.  It is alarming that even the already-polished items were rusting just as bad.  Since I live downwind of a powerplant, I am worried that perhaps the rain is a bit more toxic here, and that may be the reason for this.  If not, any ideas on what's causing this?  And since I don't have room indoors right now, does anybody have suggestions on how to stop this from happening?  There's not much of a point in shining and polishing everything if it's goign to continue wasting away.

[Mimbrogno]

There's not a whole lot that you could do about keeping iron items nice and shiny when they're outdoors. The basic fact is, any and all exposed iron surfaces will have rust forming on the surface in a month or two. It doesn't matter what part of the country you're in, if ther'e water in the air, iron will rust. I live out in Phoenix, and even thought it may be pretty dry here, unpainted steel will rust surprisingly fast.

Also, by polishing you steel, you tend to accelerate the oxidizing process, as you have just prepared a clean, pure steel surface that the water can get to right away. Items that are covered in grease and crude generally won't rust underneith that armor of dirt, unless there is water trapped benieth it.

If you want to protect the polished finish of your metal without painting it, here's what you do. Yo out and get a clear varnish like the kind that's used to protect paint finishes. Spray cans of clear coat paint would probably work best for you. You should find those at a local hardware or paint store.

Good luck with your scavenging!
Matthew Imbrogno
Mechanical Vollenteer, Arizona Railway Museum.

[selector]

Unfortunately, not to be argumentative, even many varnishes won't do it.  Many of them tend to be porous, believe it or not, and will still let some moisture in over time.  At least, this has been my experience with Varathane and other varnishes that I have used in attempts to stave off oxydation and corrosion.  Add sunlight, and you accelerate the problem that much more.  Leave the objects out overnight, exposed to the moisture-laden morning air, and it gets worse.  I have tried WD-40, machine oil, gun oil, and even a light film of grease...the latter being the best of the lot.  You would almost have to display the items in a hermetically sealed case purged with nitrogen.  On the other hand, there are always more spikes.

Microscopic water droplets will have a high content of dissolved oxygen which, when in contact with easily oxydizable metals, like iron, will bond with the available molecules producing microscopic bits of rust.  Over time, they add up.

 

Tempus edax rarum.   "Time is voracious."

[ndbprr]

I would think the grease and oil dropping from the bearings, gears etc. could have contributed to minimal protection.  I'd spray them with WD40 or the equivalent.

[NS2591]

Let em rust. The Rust Accutually helps protect them, Look at Couplers, Even brand new ones are rusty, If also helps show cracks

[CSSHEGEWISCH]

Keep in mind that oxidation serves as the protector for Cor-Ten steel, often used as a building material and best known around here as the material used to make the Picasso sculpture in the Daley Center plaza.  It is not unlike the green patina on copper and copper alloys.