Out door train layout - stainless track needed?

Tinplate track is going to rust.

Outside, Atlas track would be the way to go, as the ties are UV stable and the nickel silver rails will not rust.

You could also use gargraves stainless, which is also designed for use outside.

Also, dont grease the track.... grease attracts dust and dirt, and will just cause junk to build up in the wheels and gears. Plus traction problems.

FUN FACTS:  Steel is a product of iron and carbon. Stainless steel contains iron, carbon, and anywhere from 12-30% chromium.

Stainless steel encompasses other elements like nickel and manganese, but chromium is the key element that makes it rust-resistant.

When the surface of typical steel is exposed to oxygen, it always forms oxide (Fe2O3), which has a popular red rust color.

Ferric oxide is not capable of forming an endless layer on the steel because the oxide molecule occupies a larger area than the underlying iron atoms. It eventually wades off, leaving raw steel exposed, which then starts an inevitable rusting cycle.

So how is rusting prevented?

When stainless steel is exposed to oxygen, a layer of chromium oxide forms on the surface. This happens because chromium has a very strong affinity for oxygen.

The chromium oxide, in most cases, is a very thin layer that doesn’t spawl off. It prevents any further oxidation of the stainless steel.

However, when chrome steel is scratched, and therefore the chromium oxide layer is removed, a replacement chromium oxide layer will form and protect the remainder of the chrome steel beneath it.

Train wheels can scratch the surface.  So stainless steel is NOT entirely rust resistant.

FUN FACTS #2  NICKEL SILVER

There will be no corrosion as long as the nickel coating is intact. However, if the nickel is eroded through to the metal, a rust spot will appear. This will normally “rollback” the plating, exposing more metal bit by little, allowing the corrosion spot to expand.

Thus, if your train wheels scratch the surface of the nickel Silver rails . . . .RUST will form.

Sadly, there is no way of avoiding rust on any train rail in a normal outdoor weather situation.

___ "RUST is with us" is the one thing I recall from my Engineering Materials Courses.

Apparently there is more than one kind of NS rail. I have 700' of NS track on my layout, there is no Nickel plating. In laying the turnouts the rail was cut, ground, filed and soldered. The rail is identical all the way through.

Like the OP, I also live in South Orange County, I am near the beach in saltier, more humid air.  Track with NS rail is fine outdoors as long as the ties are UV resistant. I would not use hollow rail, or any track with metal ties, the ties will rust. I have seen outdoor layouts in SoCal, they used NS rail.

One increasingly popular option around the track corrosion issue is battery power, especially with outdoor layouts. I have that dust problem even with an indoor layout in the San Fernando Valley of L.A. and battery power works out nicely.

When you have metal to metal contact that creates surface wear that "over-time" deteriorates the coatings.

Now with battery power, you could coat the rails with some sort of polymer or liquid rubber but over time that coating wears down as well.

So each of the coated metals provide some rust protection for a while, then you need to replace.

If the stainless steel is good quality it will not rust. If it gets scratched it will form new chromium oxide layer. The chromium is not a plating on the outside of the rails, it is in the alloy. Where you see rusting is in the 'chromium steel' where they plate common steel with stainless on the outside, cheap marine stainless does that and if the underlying steel is exposed, it will rust and also will likely spread.

Nickel Silver should not rust either, as far as I know the nickel silver they use on track like atlas is an alloy, it isn't nickel silver plated over brass or something that can tarnish if the nickel silver coating rubs away.

I have seen both Atlas NS and Gargraves track used outdoors and from what I was told it worked well.My only concern with the Atlas track is how UV resistant the plastic ties are, if it is done right the ties will last a long time. Wood ties obviously can rot, I have never tried it but I wonder for outside track if you could use something like creosote or other wood preservatives to protect the wood (hey, would be prototypical).  For plastic ties you can paint them to give them added UV protection.

If you can find brass rails a lot of garden railroaders use it

Unless you plan on running your entire collection of engines outdoors, dead rail is the way to go. Start with either quality nickel silver rail with plastic ties, or Gargraves SS track with plastic ties. This is basically to give you a nice, maintenance free (ish) base to start from. Then battery power your engine with the wireless remote control system of your choice, and you're good to go. I believe Gunrunner John has equipped at least 1 of his engines to be switchable between track and battery power, you may want to do a search for that...

About twenty-five years ago a small train club in the Bakersfield area built a layout under roof(only).  I haven't heard anthing about them for several years  They were running Premier engines, many Pecos River cars on Gargraves track.  John