Adding the Unimin Mine - Part 2

In a previous post, I described how I created the walls of the open pit mine as a background to my Unimin mining area, using a number of rock castings to portray the mined area.  This posting continues from that point, and I describe how the mine area was completed, using dyes to color the rocks and other materials to simulate the base of mining operations as well as blending the scene into the rest of the Unimin mine complex.

This photo shows the completed castings in place; gaps have been filled with spackle.  I added Sculptamold to the top of the hillside in order to smooth out the surface and give a slightly rounded top to the hillside, which will be planted with trees, bushes, etc as a final step.  While the top of the hillside was drying, I used dry wall compound or spackle to fill in any large joints which were present due to the castings pieces.  

Gray and white wash added to castings; top of hillside painted and ground foam applied.  I've also started to add the last wall in the bottom right of the photo.  I ran out of the pink foam board, and started to use some floral block in the upper right corner of the photo. Both are easily sculpted to the desired final shape.

Once everything was dry, it was time to get out the knives and start chipping away at the castings and spackle, to create the final shape of the rock face.  I've found that there really is no secret to this, unless you're trying to carefully follow a photograph.  I simply start changing the rock face by gouging the plaster, pulling deep cuts with my knife, until the shape takes on the appearance I'm looking for. Maybe this is where my geology background comes into play, as it's fairly easy to visualize the fissures, cracks, joints, etc in order to give the rock face a certain craggy look and feel.

For the mined road surface or bench, I simply added some spackle and dry plaster of paris onto the surface to complete it.  I don't want the surface to be perfectly smooth, rather the floor has to have the appearance of an area that has been mined but not so rough that trucks can't navigate on it.  Next come the difficult part, coloring the rock to the right color and consistency.

I like to use various colors of dyes to add color to the casting, rather than buying some of the commercially available liquid pigments.  The liquid pigments do a good job, however, you generally get one color per bottle and the bottles are about twice the price of available concentrated dyes.  I have found that Rit Dyes are inexpensive, come in a variety of base colors, and really set the color well in the plaster. One other advantage is that Rit has done some of the leg work for you, as their website provides a series of colors and what amounts of the colored dyes are needed to produce the final color.  I have colored many rock castings on the layout and still using my original bottle of Rit black dye after all this time.  I'm sure I would have gone through many bottles of liquid pigments rather than one.  Plus, I can easily make custom colors and if the results aren't to my liking, toss it without the feeling that I just used a good amount of the liquid pigment.  I mix my dye in a 70% rubbing alcohol solution.

I have a series of small, plastic screw-top containers that were bought at a discount store that hold approximately 2-oz of liquid and these are used to store my various color combinations. Before applying to the scene, I always like to test a small casting for the correct color content.  For example, to cast the plaster in a gray color, I have series of bottles ready, each with just a few more drops of black dye in them than their surrounding bottle, which allows me to darken the gray as necessary.  Remember to always start with the lightest color and work towards darker colors. 

Tools of the trade

Same area after several washes of gray have been applied.

Here's a photo after the initial "tan" dye has been applied.  It doesn't show well in the photograph, but the stark whiteness of the casting has been toned down and the plaster rock takes on the appearance of a more off-white color.

For the mine, I didn't want to add too much color to the castings, as the rock walls have a very light gray color to them when weathered, although they seem to take on more of a white hue on a fresh cut of the rock.   I always start with just a few drops of dye in the alcohol, progressively adding a few more drops of black dye to each bottle and testing each color before I apply it fully. 

Active mine area. Note that the rocks are a very light gray and in some locations appear to be white on a fresh cut of the rock face.

Here's the final version of the mine, although I need to undo some of the weathering I did as I'm not happy about some of the large "splotches" of gray or black in areas.