Hi Big Jim,
You're absolutely correct! Black has been the recommendation with aircraft and scale model car hobbyists.
Of course isn't it funny that, compared to other scale transportation modes, model trains are always the "oddball" in various scenarios, including painting?
As I mentioned, modelers years back complained that Aclad2 was not a good product for scale SS rail cars because the results were too dark for Austenitic 300 Series Stainless Steel.
I applied Alclad 107 to a Rivarossi passenger car shell and noted that the tone appeared much too dark. It was frustrating, but I felt that this product had too much potential so I started experimenting with it. I went into "Paint and Body mode" (I ran a transit system body shop years back). It eventually dawned on me that the metalizer wasn't the problem.....the foundation was. After performing research on Austenitic stainless steel's characteristics and consulting with a friend who is a CSX manager, I narrowed my focus to dark blue and gray. Gloss Grays ranging in tones, from Light to Charcoal, won out and it's been a fun ride since! I shared my results on several forums and the interest and response has been positive.
Norton,
I haven't refinished any O-Scale units yet, but that is on my agenda. Based on my experiments, I'm estimating that if you are good with the airbrush in laying smooth coats, one bottle of Alclad 105 will metalize 1 to 2 cars, depending on your application technique. Remember that the key to applying Alclad is to "mist it on", not splashing it on wet. I normally apply 2 to 3 mist coats in long, even horizontal strokes with 3 to 5 minutes between coats in warm temperatures. Once I'm happy, then seal it with Clear.
However, consider these factors.
1. Are the roofs of your cars being metalized too, or just the sides and the ends? For ACL, FEC, SCL, NYC, and Nickel Plate, the roofs would not be metalized so that's less Alclad that would be used.
2. Do you have a good compressor that is equipped with a water trap and maintains steady air pressure?
3. Airbrush: Needle and aircap set up. A medium size needle and aircap works well, but a "fine" needle and aircap set up atomizes very well and uses less material.
By all means go for it and if I can be of help, email me anytime. I would respectfully suggest that you practice first on clean scrap plastic. (Smooth compact disc cases are excellent airbrush fodder! People nowadays throw them away. )
Charlie,
Thank you. Do you have photos that you can post?
High Greens 
