This article will take you through my simple techinque for making mile markers. I model the square concrete marker, but the technique works for other styles as well, including whistle posts.
I start with "plain old" square toothpicks which measure about 10 inches square in N scale. One end is left round and pointed ( most square toothpicks have round ends ) for easy "planting" in the scene if your base is foam. Later, you will trim the point if your scenic base is wood or plaster.
Using a hobby saw or wire cutter, I cut down the toothpick to the right length from the bottom, about 1 inch. This will leave about 1/4" margin for error and some squared off area for just below the ground cover. The height above the ground will vary by prototype but about 1/2" looks good. Next, using a sharp hobby knife, I trim the top faces at a 45 degree angle doing oppossing sides and forming a point at the tip. When I am satisfied with the basic shape, I sand the marker lightly, especially at the top. The wood is now ready for painting.
I paint the mile marker using gloss white paint, either Testor's or Polly S. I grasp the round pointed end of the marker and dip the top into the jar down to below the start of the taper. I hold it in the paint for about 30 seconds so that the paint penetrates well. Next I temporarily plant the marker in a scrap piece of foam to let it dry. A second or third coat may be needed, you can judge by the grain coverage. Either way, sand the marker lightly with extra fine sandpaper between coats and before making the final decision.
When the finish is satisfactory, it's time to apply lettering. I use dry transfers from CDS or Woodland Scenics, usually the gothic railroad lettering set. I tape the post down to my work surface with masking tape applied lightly to the bottom. Next I apply the letters and numbers per the manufacturer's instructions. Check what convention your railroad uses (or used) for mile marker numbering. My sample is marked "JC 52" ( with the 52 below the JC ) indicating 52 miles to Jersey City.
Finish your mile marker by applying a light coat of clear paint, such as testors DulCote®. Next "plant" your marker in the scenery. If your scenic base is foam or foamcore board, just press the marker into the ground, remove it, dip it in white (or wood) glue, and replace it in the hole. If your scenic base is wood, plaster, or Sculptamold® you will need to drill a small hole to plant the marker in. Cut the point down to fit the hole, then dip it in glue and plant it in the hole. Fill in scenery material around the base to finish off the installation.