Tips, Tricks, and Lessons Learned

Building a model railroad layout is a continual learning experience.  Some things that you learn about and try, work great.  Others, not so well.  This page is an informal collection of some of the tips, tricks, and lessons learned that I've encountered while building the Willow Creek.

Extending the Working Time of Plaster of Paris

I use Plaster of Paris for the majority of my scenery. Plaster of Paris normally sets up in as little as 10 minutes.  When working on some scenery areas, such as the large river bed for the Naugatuck River, I really need to have more working time to smooth and form the plaster.  I normally mix 1 cup of Plaster of Paris at a time (1 cup of dry plaster mixed with 1/2 cup of water).  By adding 1/2 teaspoon of Baking Powder to the Plaster of Paris mix, I can extend the working time of the plaster to 30 - 45 minutes.

Fine Sand for Scenery

I like to use real sand as one of my many ground covers.  Playground sand and other commercially available sand that I've found has small shiny specks of mica in it, which I find unacceptable for my scenic requirements. To avoid this problem, I purchase "parakeet grit" from my local WalMart store. This comes in a small box and is a combination of fine sand, chunks of clay, and some small gravel. I sift the grit through a very fine seive, like a tea strainer, to eliminate the larger chunks. What's left is very fine sand that doesn't have any of the shiny specks that are found in other sands. 

Plaster for Carving Rocks

I learned to carve rocks out of plaster. The technique I use is perhaps the subject of a latter "tip."  A key to the rock carving is to have the right mix of plaster. Again, I use Plaster of Paris.  I mix my usual 1 cup of Plaster of Paris to 1/2 cup of water.  As I'm mixing the plaster, I add 1/8 cup of fine sand (see the preceeding tip) to the mix, and stir well.  The result is a gritty plaster mix that takes on the light tan color of the sand.  I apply this mix to where I want to carve rocks. The mix has several benefits. The sand extends the working time of the plaster to at least 30 minutes, which gives me more time to carve rocks. As I carve the plaster to make rocks, the sand grit is exposed and makes a very nice surface -- much better than the typical smooth surface of plaster. The dry plaster-sand rocks are extremely hard and durable. If you stain the plaster-sand rocks with Woodland Scenics pigments, for example, the sand also causes the stain to affect the rocks in a non-uniform manner, making for a more realistic rock face with some nice color variations.

Thoughts About Using Joint Compound

I frequently mold plaster rocks using Plaster of Paris and Woodland Scenics rock molds. After the rocks are applied to the scenery, I used to use joint compound to fill in the spaces between and around the Plaster of Paris rocks.  Beware, however, that different types of plaster absorb stains differently. I found that Plaster of Paris usually absorbs the stains nicely, but joint compound did not. This left me with blotches of mostly unstained plaster between and around my Plaster of Paris rocks.  Acrylic paints or other coloring materials can be used to resolve this problem.  Or you can stop using joint compound, as I did.

Also, joint compound tends to shrink and crack if it is applied thicker than just a thin skim coat. Joint compound is handy and simple to use; no mixing involved. Just be aware of its limitations. I've found in most cases that it is better to mix up a small batch of Plaster of Paris than use joint compound on my scenery.

Water

I've used several techniques for modeling water.  For standing or relatively still water, I've found that EnviroTex Lite and Magic Water two-part resin products both work well.  You just have to deal with the "creep" of the resin that affects scenery surrounding the water area.  Follow the manufacturer's instructions for using both of these products.  For flowing water and large bodies of water, such as the Naugatuck River, I used Dave Frary's technique involving acrylic paints for the bottom of the water area, and then acrylic gloss medium (e.g., Mod Podge Gloss) for the water.  Frary's techniques result in great looking water at a fraction of the cost of using one of the two-part resin products.  The water in the Naugatuck River consists of 10 coats of gloss acrylic medium and a final coat of acrylic varnish. Dave Frary's techniques are described in his book, How to Build Realistic Model Railroad Scenery.