How do you do it?

Paint  (I like Floquil.  Acrylics don�t cover to well yet but they great for weathering.

Rolling Stock.

TECH   NOTE:

To achieve the effects of the 5 keys, I usually prefer to use paint for the most part.  You don�t quite get the coverage or color with most chalks.  With the car apart, spray the underside with whatever color is correct or the color you want.  Then mist a coat of Grime.  Mud is often kicked up onto the bottom of the car - usually around the trucks.  I used a couple of different methods for this.  You can dry brush or you can dip a brush into the paint jar, wiping off the extra on the side of the jar. Then aim the edge of the brush at the model, and drag your finger across the brush.  This will send paint flying onto the model�..and everything else.  Please remember to cover your work surface and anything else you don�t want to be �Muddy�.  I then use RustAll to rust any �metal� parts (ie around trucks, couplers, brake gear).  Next go over it with a mist of Grimy Black on any part that would move on a real box car.  After the paint has dried, rub dirt into the part, or mist on a very thin coat of Dust.

TECH   NOTE:

For the sides and tops of a car, the first step is to make the lettering look faded.  This is achieved by misting a thin coat of paint that is the same color as the car�s base color.  So if the car is Red Oxide then mist Red Oxide over the lettering.  The color does not have to be a perfect match, but it is important to get it as close as you can.  Then I add some rust, usually by dry brushing.  Remember anything on a vertical surface that streaks or runs will do so up and down due to gravity.  Chalks also work well for this.  You will want to add something to represent dirt around the bottom of the car.  This can be done with Dirt or chalks.  It can also be done with the airbrush.  Remember to use up-strokes so it looks like the wheels have kicked up dirt.  If it�s a wooden boxcar or a new 60 footer it�s going to rust.  Rust any metal supports and parts on the older wooden cars and the entire side of the metal cars if you wish.  Rust colored paint can also be thinned and misted onto the sides.  Stock cars will also have a white-ish stain around the bottom of the car.  The lime placed on the cars floors causes this.  If the car is a double deck car (For Sheep and Pigs) you may want to have this stain start at the bottom of the top deck and continue down the side of the car.  For this, you can thin white paint, or you can use chalks.  The roof, or top of the car will have soot of some sort regardless of which kind of motive power you use.  It is heavier on steam era cars.  Cinders and soot can be done with chalks or the airbrush. Take a bottle of Grimy Black and use it full strength.  You will have to add some air pressure to pull the thick paint out of the jar.  Back away from your model and spray.  The idea is that you want the paint to be almost dry when it lands. Remember to rust any metal parts like break wheels and stove pipes (on passenger coaches and cabooses).  You will want to add the rust before the soot.  Once the car is weathered to your liking you will need to seal it with a dull clear coat.

Locomotives

TECH   NOTE:

Like weathering a boxcar you use the same principles.  Cinders and soot are put in place as before.  The calcium deposits on leaky fittings can be created with chalks.  When making an old stain that has run down to a joint, seem or pipe you can first dip a small brush in water.  Place a drop of water on the model and let it, or help it, run where you wish.  Dry off the brush then dip just the tip of the brush into a jar of white acrylic paint.  At the highest point of the water you just put on the model touch the white paint to the water.  The paint will then mix with the water and run down.  This will dry and leave a nice thin white stain that has run just like the real things.  Coal dust should be heavy around the cab, tender floor, and around the front part of the tender. Remember, tenders tend to overflow and spill when they are being filled.  This will wash the coal dust off and cause rust.  Again, the 5 keys apply.  Faded lettering also applies.  Most steam engines where black with white lettering.  Either by dry brushing or with chalks you can create the illusion of the paint washing off and down the side. Using the same color as the lettering dry brush down the side starting at the top of the letters.  On diesels you will also use the 5 keys, faded lettering, a small spill on the fuel tanks, and exhaust stains on the top of the engine.  The spill can be done with chalks.  The exhaust stains can be done with an airbrush.  By using full strength paint, adding more air pressure, and backing away from the model it will create a unique effect.  The reason is that the paint falls onto the model.  It is also dry when it hits.

Structures

TECH   NOTE:

The alcohol stain is wonderful for making water stains on any surface.  I use the light stain for the general weathering and for details.  For water stains, I like to use the darker stain.  If the stain is a little too dark you can dry brush over the stain with the same color as the wall.  For the dirt around the base of the building you can use the real dirt or chalks.  Start at the bottom of the building and pull the chalk up the side.  You don�t want to go very high.  Remember, this is representing dirt that has been kicked up by rain.  It shouldn�t go much over 2 - 2 1/2 scale feet.  Rust any exposed metal.  On older buildings use a general misted top coat of grime and or dust.  This will add age to the building and give it character.  On buildings with a painted surface you can make the paint look like it is peeling.  There are several methods to doing this.  My personal favorite is the dry brush.  If you are working on a house and you want it to look old, the walls first need to be painted a light gray color.  Then dry brush the paint color over the gray.  The gray will look like the wood has been exposed to the elements.  Follow that with the stain and you have it.

Scenery.

TECH   NOTE:

For oil stains on the streets nothing beats chalks.  You can brush the stuff up and down the road.  It is easy to correct mistakes.  
Always keep the 5 keys in mind.

For freight cars as an example you start with a base coat of paint is Grey Primer followed by Roof Brown, Depot Buff, Grimy Black And lastly by what ever version of box car red you use.   For any other type of car or structure you simply substitute the box car red coat for what ever color you choose. 

I have found that this creates a great effect but you want to be careful about your hands and your work surface. This will leave small strands of fiberglass around and will have to be carefully cleaned. The eraser tool that I bought came from PBL (The Sn3 people) Micro Mark also has this tool available from their catalog. Mine also came with a brass brush that you can load into it that is handy for cleaning locomotive wheels as well as the scratching method of weather.