Tip #6: Car weight.
I found a couple references to what an N Scale cars should weigh. One reference stated that the car should be .25 oz per car, plus .25 oz per inch of car length. (i.e. a 3 inch car would be .25 + .(25 x 3) = 1 oz).
The other reference I found recommended a car weight of .5 ounces per car plus .15 ounces per inch of car length. (i.e. a 3 inch car is .5 + (.15 x 3) = .95 oz).
For a 3 inch car, the weight difference of .05 ounces between the formulas is hardly noticeable. But, for a 4 inch car, the weight difference is .15 ounces. And is .25 ounces for a 5 inch car. As you can see the difference can get significant the longer the car gets.
So, which formula is the correct one? Good Question!
I tend to like my cars a little lighter. The heavier the cars are, the more friction they will put on the trucks (wheels), and then will be harder to pull (ie... you will not be able to pull as many cars). If your cars roll well and have decent trucks/wheels, then it should be acceptable to have the car a little lighter than either formula states. I would use the weight formulas as a way to find out if a car is grossly under (or over) weight.
(Formulas are offered as information only - use at your own risk.)
(this is copied from an older N-Trak newsletter)
These are notes I have collected from on-line forums that have discussed stripping paint off of locomotive body shells.
(from a Model Railroader Magazine)
I use a Badger model 200 Airbrush with the large nozzle. The air pressure set at 15 psi maximum. The lower the pressure, the better. Pressure too high will cause the paint to dry in the nozzle.
Mix paint with a couple drop of the Accu-Flex Retarder per bottle. And, reduce about 20-25% with Golden Mediums Reducer, which is available at Michaels craft store (Golden Airbrush Medium #3535-4).
It is also important to make sure that the paint is free of clumps and debris. It is easy for the paint to develop clumps and clog the Airbrush nozzle. Strain all particles out before use.