Craftsman Tool Chest: 4
Assembling and Painting Plastic Building Kits
By George Riley/photos by the author
It is a rare model railroad in this day and age that does not host at least one plastic building assembled from a kit. Most of us have our layouts populated by dozens of these readily available and easily constructed scenic structures. The appearance of these plastic buildings are greatly enhanced by paint and finish.. This will elevate a common kit to a layout’s focal point in a few easy steps.
Among the advantages of plastic kits besides their relative ease of assembly is the minimal number of tools required for their construction. Since nearly all of the pieces are molded in the correct shape and size most of the tools are used to remove the parts from their carrier sprues and to clean off any burrs and flash them.
Look over the tool list before getting started with your project and add the missing items to your tool kit. Since these tools are readily available and inexpensive one should be able to fill out their tool box for around $20.00.
Step One – Assembling the Carcass
Begin by assembling the walls using liquid styrene cement. This type of cement will "weld" the pieces together making for a strong and long lasting joint. To assure that these joints are tight the pieces can be clamped until the cement has fully set. Make certain that the walls are square by checking their alignment with your square as you proceed with construction.
With the walls assembled they will then need to be attached to the building’s foundation. At this point a decision needs to be made as to which detail parts will be attached to the structure. As a rule leave off those parts that will have a different finish color from that of the overall building. For example, if both the building and windows will be painted white, go ahead and install them. However, if the building is tan and the windows white, set the window castings aside and paint them separately.
With basic assembly complete, set the model aside and allow the cement to fully harden before proceeding.
Step Two – Priming
To provide a base for the color coats of paint to adhere, the entire building is given an overall coat of gray primer. This has a secondary benefit in allowing the true colors to show since they will not be shaded by the molded color of the plastic. For most colors gray works well since it is opaque and covers the base color, however, for white, yellow, orange and occasionally red, a primer coat of white will work best. The primer can be applied with a brush, spray can or airbrush with good results. For this project a commonly available aerosol spray gray primer was used.
Remember to always work in a well ventilated area or out of doors when using spray paints since the fumes can be harmful.
At the same time that the primed carcass is drying, the small parts were primed separately and given a color coat while still attached to the carrier sprues. Leaving the small parts on these sprues allows them to be more easily handled.
The window frame inserts were to be white on the finished model so these were sprayed with two light coats of flat white spray primer while some of the other small parts were primed and later brush painted in appropriate colors.
Once the primer had dried hard it was time to add the finish paint. Paint has ‘dried hard’ when it has completely dried or cured and no longer has a smell.
Step Three – Masking and Adding Color Coats
Whether one chooses to airbrush, spray or brush paint their models it is usually a good idea to mask off the areas that will have differing colors applied. This is easily done with masking tapes that are readily available from a variety of outlets. The newer blue and green versions seem to work best for model use since they have a lower tack than the old tried and true khaki colored tapes. Having lower tack means that the tape is less "sticky," this minimizes pulling off previously applied coats of paint and primer while still sealing the color separations adequately.
Once the masking is in place, the various color coats are applied. Set the model aside so the paint will set. Usually most model paints will set in a couple of hours. At this point the paint is dry to the touch yet still retains some flexibility. Peel off the masking tape and let the paint continue to dry overnight.
Step Four – Applying Special Finishes – Wood Grain
The backs and sides of our a number of the Wild West models in addition to the privies and sheds would be finished in "unpainted wood." Over the gray primer base transparent stains of various shades of brown acrylic paint thinned with tap water are brushed onto the model. A medium brown (Polly Scale D&RGW Building Brown) and a darker brown (Polly Scale Rail and Tie Brown) thinned with water were randomly brushed on to simulate the varying wood tones. The graining can be further accentuated once the stains are dry by the use of a fiber glass eraser to scour the finish.
Step Five – Adding Depth - Using a Dark Wash
In the real world, light and shadow add depth and texture to our surroundings. To accomplish this play of light on our small models one needs to resort to a bit of visual trickery. By applying a dark wash that will pool in the crevices and detail of the model’s surface, shadows are created to enhance this appearance of depth and realism.
One of the more common ways to add this shading is to use an alcohol base wash colored either with black India ink or black or dark gray acrylic paint. This mixture can be made by the modeler by trail and error or purchased ready made from a number of vendors. These washes will work not only for toning plastic models, but are also useful with wood, card stock and other media.
All one needs do is to liberally apply the wash over the model and allow it to dry. If the results are not as dark as wished, additional applications are used until the desired results are reached.
Step Six – Painting the details
By this point the model is starting to come together. The builder is now at the stage of painting and adding some of the added details that really make a model stand out. Details parts can be painted using any one of the various application methods, however, it is frequently easier to brush paint these small parts. A smoother finish is often obtained by thinning the paints so that they flow easily. Often more than one coat is needed to completely cover each item. Do not hesitate to mix and blend various colors to get the exact shade or finish on a part.
Step Seven – Dry Brushing
Just as a dark wash is used to accentuate the details and crevices on a model, dry brushing with a light shade of paint replicates the play of light of our models. The "Dry Brush" technique is easily mastered. One simply wipes off most of the paint on their brush and then scours the surface of the model thereby highlighting the raised details. While the best results using this technique are had by using specialized brushes to apply this finish, a firm soft bristle brush can be pressed into service.
Step Eight – Applying Special Finishes II: White Washing
One of the most common finishes used in the nineteenth and early twentieth century was "white wash." This was made by mixing water with lime to yield a flat, white preservative coating on wood. Since this mixture lacked any binding agents it would wash off in a year or two’s time and would need to be reapplied regularly.
White Wash can be easily simulated on models with the use of flake white oil artist oil paint. By heavily dry brushing this paint over a previously wood grained model one can capture the hit and miss nature of this finish.
Step Nine – Final Assembly: Signs, Window Glass and Such
As final assembly approaches all that is left to do to finish the models is to add the window glazing and attach the signage. One of the biggest challenges when glazing the windows is to get a neat installation with out glue smears and chemical crazing on the clear plastic. While the ACC glues are easy to use and set quickly, one of the side problems of their uses is that they frequently will cloud clear parts. Liquid plastic cement on the other hand is hard to control. The easiest and cleanest way that I have found to install clear plastic glazing in plastic models is Testors Plastic Model Cement. This product has a thicker body than the regular liquid cements while flowing easier than the old school tube glues. In addition this glue can be used to attach parts to painted plastic surfaces with a high degree of success.
Many kits include signs printed on paper stock to be added to the finished models. After cutting out the various signs, attach them to the building with a PVA glue. This water based clear drying adhesive is also useful for attaching figures, separate details, scenery items and clear parts. Finally, check over your work and touch up any paint work necessary as well as fix any loose or misaligned parts.
Step Ten – The Big Finish
By following these easy steps and using some of the tips and techniques presented here, the completed models assembled from basic plastic kits are ready to be added to the layout. Plastic kits have long been one of the easiest ways of getting started building models. They offer a wide range of inexpensive, readily available and easy to build scale models.
If you are interested in modeling the scenery and buildings of the "Old West," you may also want to consult "Modeling The Wild West" from Carstens Publications.