Two easy methods to simulate the mortar lines and other color variations on any molded brick wall surface. It works with any plastic kit, as well as with resin or cast plaster brick kits.
By Robert Schleicher
Keep a damp rag or paper towel handy so you can quickly wipe over the surface of the bricks to remove a bit more of the mortar color. Use this technique to provide subtle variations in the lightness of the bricks that show through the grey wash by rubbing more or less in different areas of the wall. Later, a wash of brick red can be applied for another variation in overall wall color.
Molded brick (and stone) surfaces are just one of the many intricate details that are effectively rendered in plastic in the various model structure kits in N, HO and 0 scales. This same type of brick detail is also available as injection-molded sheets of solid brick surfaces (or stone or shingles/roof tiles) from firms like Kibri, Vollmer and Faller as displayed in the various Walthers catalogs.
One of the better kept secrets of the hobby, however, are the molded plastic brick sheets produced by Plastruct. These sheets are available in a variety of brick, stone and shingle surfaces in most scales (including G). The advantage of this particular brand (available to any hobby dealer) is that the sheets are not molded in the same manner as the walls in kits or the blank wall sheets from Kibri, Faller and Vollmer. The Plastruct sheets can be used like the plain plastic sheets from Evergreen (Plastruct also offers plain plastic sheet, by the way). You can lightly scribe or score a line on the surface, then bend the plastic over a square table or board, and the plastic will break cleaning along the line (this is the "snap out" technique shown in the July 1990 issue). If you try that with the molded plastic brick from Faller, Kibri or Vollmer, or with any of the kits (except the kits produced with Evergreen sheet styrene walls like Ever green's own and the new Howard Zane kits shown on page 3 of the November 1990 issue), the plastic will bend rather than break, and if you force it, the plastic tears into ragged layers or laminations. The only way to cut those molded plastic walls or sheets is with a razor or scroll saw, and that takes some effort. The article in the July 1990 issue explains the near-effortless techniques, with photos of each and every step, to "snap-out" walls, window and door openings and roofs from sheet styrene. Those techniques will also work with Plastruct's brick sheets.
The articles in the December 1990 and January 1991 issues by John Nehrich describe how to use the thin Holgate & Reynolds brick, stone and shingle sheets with the same "snap-out" technique with the H&R sheets, however, a second wall is required to reinforce the outer walls (that's what's explained in those articles). The Plastruct sheets are thick enough to be self supporting.
None of these kit walls or brick or stone sheets are ready to use without some additional painting. Most of the kits and the various brick sheets are molded in colors near enough a brick shade. Usually that is red, but a few kits have yellow or beige brick. Red, grey, yellow and beige are available in the solid sheets of brick from Kibri, Faller, Vollmer and Plastruct. For these products, the "missing" color is that of the mortar. The indentations are there to show where the mortar lies, and in N scale, that is sometimes enough. For HO or larger size bricks or stone, however, the mortar is a visible line of slightly lighter (or occasion ally darker) material. Note that I said "slightly." Though mortar is grey or white, it takes on some of the color of the surrounding brick or stone, if only as a reflection. The most effective color for modeling mortar, then, is usually a light to medium grey (unless you are modeling a specific building with black or other unusual mortar colors), thinned to produce a "wash" that, when applied, allows some of the underlying color to show through the grey. Thin any paint with about 19 parts thinner to one part paint. Use acrylics or Polly S for this, with water as the thinner, and add a drop or two of detergent to cut the surface tension of the water so it will flow more freely and with less puddling. Start with too thin a color - too little paint and too much thinner - and if the effect is too subtle apply a second coat. If the effect is too light (that is, the mortar color covers the darker brick color) when you first apply it, rinse the paint off immediately and mix more thinner into the paint before trying again.
There are many techniques for painting brick surfaces. The method of simply using a "wash" that automatically applies mortar color and tones down the brick is by far the easiest and quickest. If you have a brick material, like Holgate & Reynolds, that is white, simply spray it the color of brick you prefer. It's wise to match the brick color to a real building, but a mixture of about equal parts Floquil Caboose Red and Roof Brown should be a place to start in matching the color - add more or use less red and add black or white if necessary to come closer to dries, simply proceed with the wash of mortar color.