how are train painted

It's not so much the painting as the prep work.  The masking is the most difficult/time consuming aspect.  You have to carefully cut and apply the masking material (note I aid material because it could be tape, foil, film, etc).  This doesn't make for scintillating video and its hard to video and do the work at the same time.  American Chopper had sequences with complex masking schemes being done on some of the custom bikes, particularly fuel tanks.  Not much difference other than the shape of the object being painted.

As far as the paint goes it does help to know/understand order of color application and why it might be better/easier to go one way or another.  The most astounding thing to me on a tour of the old Lionel factory back when it was in Mt. Clemens, MI was to see the 20+ step paint masks used for the F-3 Warbonnet (only the oval nose herald was a decal).  The way those were painted was nothing like a DIY would ever think/try.

The model companies develop paint masks for each color applied over the base color.  It would be impractical, expensive, time consuming and too variable for them to tape/foil/film every unit through the paint shop.  Plus, some striping and lettering will be applied by a printing process.

Rusty

Think WEAVER was using stencils for painting the boxcars during a plant tour. WEAVER TRAINS also uses pad printing, especially for the custom runs.

The use of precut masking is also a common practice. First a master is made for producing the precut masking.

When they were made in the United States, Lionel used "paint masks". These masks had fixtures that held the item to be painted in an exact position. A multi-piece metal shell closed tighly around the item to be painted, leaving only portions exposed. Compressed air was fed into the paint mask assembly to prevent stray paint from entering.

Only one color could be applied at a time. Complicated paint schemes required multiple maskes.

The paint masks came apart, and were cleaned periodically.

Here is a picture of one, courtsey of the Train Station, in New Jersey.

http://www.train-station.com/P...PAINTMASK-18147.html

Lionel also did rubber stamping, pad printing, heat stamping and used electrocals.

If you would like to see how Lionel trains were decorated in the 1990's, get a copy of "The Making of the Scale Hudson". The video show how some other items were made too.

This brings up another topic,......"Patience & Practice"

Many of the production line painters employed these days have many hours of practice and as many hours of experience before they are even considered for the job. Patience is another animal that requires many hours of OJT.

Years ago I worked in an historic theater. There were only a few people employed there, one of whom was the house painter. He used to paint everything, including ornate plaster details, without using masking tools or tape. When I asked him how he did it, I got a one word answer: patience.

I never painted anything there, but I did pick up some tricks of the trade just by watching him. I usually do my painting without any sort of aid for cutting in, other than having a good quality sash brush.