Concrete - Make your Model Concrete Structure Look Right - a Tutorial

Because of the positive feedback we received on this recent Workbench Talk article (by Ray Del Papa and Raymond Potter) in our newsletter, we are re-presenting it here for our blog audience. Please give us feedback on what kind of articles you'd like to see here.

concrete retaining wall

Unpainted, this concrete retaining wall is made of layered sheets of plastic. Painted as we discuss, it becomes lightly weathered concrete wall, perfectly blending into the scene.

Nothing says solid and here-to-last like concrete. Concrete structures are a big part of modeling the real world, whether it’s the foundation of a torn down building, the outside of a skyscraper, a weathered bridge abutment, or just a simple sidewalk. Most materials, like plastic or resin for example, do not have enough texture to look correct straight out of the box, so a scheme to paint and weather concrete is a must for realism.

Here is a very quick and easy way to make your concrete structure look like real concrete. (This tutorial assumes you have a basic grasp of prepping, priming, and base-coat painting a kit, as well as the basic techniques of applying a wash and a dry-brush. If not, there is a wealth of information on these techniques available online at most modeling forums, and in countless hobby magazines.)

Basic Painting:

My first choice is to use Testors Flat Gull Gray as my base color, but most of the lighter color flat grays can work too. Floquil makes a Concrete spray that has a greenish tinge that can be quite effective in places as well.

  • Spray your cleaned and primed surface with your chosen concrete color, and let dry. You can brush this first color layer on, but spraying gives a more even surface.
  • Once your surface is dry, come back and brush on a water-based wash of thinned black or grimy black paint, again let dry. Washes often tend to leave bubbles. Don’t let the bubbles dry on the surface. Soak them up or wipe them off with a paper towel. This procedure should allow paint to settle into and darken the cracks, undercuts, and deep spots on the concrete surface.
  • After your black wash has dried, it is time for the dry-brush technique. You can dry brush either flat white, off-white, or light gray (I like Dove Gray by Folk Art). This will highlight the more raised portions of any surface texture. The rougher the surface, the more impressive this will look.

Now you have a basic concrete look that can be used as is if you want to simulate a new structure on your model railroad layout. This is also the recipe for creating a simple effective sidewalk.

Aging & Weathering:

As we all have heard, the devil is in the details. This applies to weathering too when it comes to getting concrete objects to look real. The older you want your concrete to look, the more you want to repeat the black wash and the light colored dry brush steps. To help determine the right shade of aging you can use photos as references. Of course, since concrete is all around us, a healthy walk around the neighborhood is another direct approach you can use to conduct your research.

  • After you have completed the basic procedures above, take some flat black and gently brush some streaks. This process works best from the topmost edges downward. This will simulate water stains dripping off the highest points. The drips will usually be broader and thicker at top and will become narrower and thinner as they progress down the vertical face of the concrete object. After awhile, you will be able to feather these streaks to varying degrees which goes a long way to simulating the real thing.
  • You’ll need a rust color if you want to simulate rusting. Burnt Sienna or Burnt Umber acrylic paints and some of the orange or red weathering chalks will work best for this.  If you have metal parts or metal roof sections on structures you can add some rust steaks here as well.  Another obvious place for rust streaks would be any metal parts that are attached to the side of your concrete walls, sidewalks, or platforms, such as bolt heads, hinges, or brackets.

Once you have settled on a weathering process that you like, it will make your concrete structures really pop out. With a little practice you will be able to ramp up the WOW factor on any concrete structure or scenic element you build.

---Ray Del Papa & Raymond Potter

Another view of the Operation Lifesaver locomotive

This smooth aluminum turntable becomes heavily weathered concrete using the techniques above with the aging process added. Note the rusty and dirty streaks that bring it to life.

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