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Building Your BASE

By Ron Marsh

All photographs by Ron Marsh

One aspect of modeling that is nearly universal to all types of modeling is scenery.  Whether you’re building a model railroad, military models, or fantasy model scenes, chances are good that scenery will be part of your model building process.  Realistic scenery can really make the presentation of your primary model subject stand out.


When we think of model scenery, we tend to think about grass, trees, structures, roads — all of which are important parts of the colorful, finished product.  But, before skipping to the finished product comes the base for our scenery.  The base can make or break not only the shape of our scenery but the weight and the ease of construction as well.


For years, I have built most of my scenery base with a cardboard lattice covered with plaster-soaked paper towels and Plaster of Paris.  (See Figure 1.)  This process makes a very strong base, but it has two drawbacks.  The first con is that it is very heavy, making it less than ideal for modules, dioramas, or any other model projects which are meant to be portable.  Secondly, the plaster is bright white, meaning that if the surface is scratched or if you drill into it to attach other scenery you have to deal with all of that white powder falling over your finished scenes. (See Figure 2.)

Ron's Workshop - July 2018 - Figure
Ron's Workshop - July 2018 - Figure

One solution to the white plaster problem is to color the plaster as you mix it.  Plaster can be colored with dry tempera paint to closely match the scenic ground color you desire.  This leaves any scratches or cuts in the plaster showing only the ground color — a great solution.  The problem remains, however, of the weight of the plaster.  If weight is a serious issue for you, an alternate base material is probably your best bet.

Perhaps the most popular alternative material being used for scenery base today is extruded foam.  Foam sheets made for construction purposes can be purchased in 4x8-foot sheets in thickness from ½ inch to two inches and more.  The foam is very lightweight, easy to cut, and sheets can be stacked and carved to make hills, mountains, and other scenic forms. (See Figure 3.)  The foam takes latex paint fairly well, so it can be used alone as a base material.


I prefer a little more texture than foam tends to supply.  I also prefer to be able to fill in any gaps or holes with some material before applying scenery material to the foam.  A layer of plaster cloth can be added on top of the foam to accomplish this purpose, but again you have a layer of white material that I prefer to avoid.


Recently, I have been experimenting with a homemade material that has been around for many years.  That material is called Ground Goop.  Lou Sassi first developed Ground Goop years ago and popularized it in model railroad circles.  It is a mixture of CelluClay (a recycled paper material), Vermiculite (a material used in potting soil), latex paint (your preferred ground color), white glue, and water.  A cap full of household disinfectant may also be added to retard mold and mildew growth if you plan to keep your Ground Goop for a long period of time.  Many variations of the mixture of these materials have been tried over the years, but I personally found that one part CelluClay, one part Vermiculite, one part paint, one half part glue, one half part water, and a cap of disinfectant worked well. (See Figure 4.)  Any Ground Goop that is left over can be kept for a long time, as long as it is stored in an air-tight container.

Ron's Workshop - July 2018 - Figures 3 a

I first experimented with applying the Ground Goop over an area that I had built with plaster.  This gave me an opportunity to practice applying the Ground Goop before trying to work it over bare foam.  The Ground Goop spread well with a gloved hand over open areas.  When I had the thickness close to what I wanted, I dampened my glove with water and rubbed it gently over the surface to smooth it out. (See Figure 5.)  In tight areas around rocks and along the base of my backdrop, I used an artist’s spatula to apply the material. (See Figure 6.)  This worked great for getting it up close to these objects without making a mess and getting it all over them.

Ron's Workshop - July 2018 - Figure
Ron's Workshop - July 2018 - Figure

I allowed the Ground Goop to dry overnight.  When dry, it left a hard, sturdy surface that was easy to drill in to and was colored all the way through, leaving no white particles behind on the finished scene.  The texture is a little rough for my taste in N Scale, but with a little light sanding and scenery material applied, I believe the texture will be unnoticeable.  If you are looking for an easy, light-weight scenery base material, extruded foam and Ground Goop may be exactly the solution you are searching for!

Happy Modeling, Ron. 

About the Author


Ron Marsh is a pastor in Southwest Missouri.  He grew up in West Central Missouri where he became a railfan of the Gulf, Mobile & Ohio and Missouri Pacific Railroads at an early age.  Ron has been a model railroader for over 20 years and has modeled 1970s Missouri Pacific and contemporary BNSF.  He is currently working on his third layout—the Texas, Colorado & Western—depicting BNSF operations in North Texas and Colorado in 2008.  He is a member of the N Scale Enthusiasts – a national organization for N scalers. Ron posts model railroading videos weekly to his YouTube channel, Ron’s Trains N Things


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