How to prevent rust

You have to control the moisture in the air. Where you live is a BIG factor.  The patio room is a better bet than the garage to seal off the area. 

You might try running a dehumidifier. There is a certain amount of hassle in that you have to empty the bucket everyday. They come with a float that automatically turns them off when the bucket gets full. If you can drain the water outside or into a plumbing drain you could run it 24/7. You could also buy a humidity gauge. This will tell you what the % humidity is in your garage and whether it is excessive or not.

I have seen this on one of the toy train review videos or ogr magazine videos of the 1990's..

One hobbyist took some cardoard and cut out the straight, curved and switch profiles. He then sprayed one side of the cardboard with wd 40 and would lay that cardboard piece on top of the track section. This would prevent rust on top of the rails. NOTICE I stated the cardboard was sprayed NOT the TRACK so the trains don't slip when you take off the cardboard and want to run trains.

Spray the track before it rusts with clear lacquer or perhaps clear dull polyurethane. give it a couple days to make sure it is completely dry and then scrape the top edge of the rails where the wheels contact.  If you have good contact on the head of the rails the flanges will clean off the sides of the rail.  In the fifties we lived in Biloxi MS. and for a while I had a layout in a shed with a dirt floor. The salt air and humidity was ruthless and I complained to my father about the problem and he handed me a gallon of clear lacquer and a fine wire wheel. Said put the wheel in a drill and clamp it down then clean the rust as best you can then paint the track with the lacquer and scrap the head of the rail once the lacquer is dry. As long as I ran the trains every day to keep the rail head clean it worked fairly well.          j