Priming and painting - how to protect and enhance your model - BASIC

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Armortek
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Priming and painting - how to protect and enhance your model - BASIC

Post by Armortek » Sat Nov 07, 2015 11:53 am

Purpose. Painting your model has two purposes, technical (protection from the effects of corrosion and abrading) and artistic (scale modelling). Painting isn’t essential. Some owners choose to display their unpainted models as artworks:

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Consider the protection of priming for models which run outdoors, particularly if conditions are damp, wet or dusty/gritty. After priming, some owners choose generic paint schemes, loosely based on historical examples, others undertake exhaustive research to replicate specific examples in their operational context, including adding surface texturing and weathering effects of terrain and use. This BASIC Topic covers generic priming and painting for Out of the Box models. In the ADVANCED section, you’ll find Topics on creating realistic surface textures, weathering, decals and stencils for markings.

Protection – the “technical” bit.

Risks. As delivered, your kit parts will have been deburred but will still carry residues of the fluids used in manufacture.

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These are not harmful but will inhibit paint adhesion. Unprotected aluminium will develop an oxidation layer which may be unsightly. Steel parts will corrode if unprotected. Where two dissimilar metals are in contact in the presence of an electrolyte, galvanic corrosion is likely. The parts most at risk are the track pins, axles, sheet steel assemblies such as bins, brackets and fasteners if not stainless. That’s the risks, now the solutions.

Process.

Step 1 – Degreasing. Parts can be mechanically degreased by sanding, wire brushing or sand/bead blasting. The easiest method, however, is to wipe with a degreasing fluid such as Upol System 20 Fast Degreaser.

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Step 2 – Priming. Use a pair of latex gloves to protect your hands and avoid contaminating the surfaces with the oils from your fingers. Now spray all the parts with an etch primer such as Upol Acid 8. It’s vital you use a mask, such as the 3M 7500 Reusable Half Mask:

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Spray in windless conditions and hang the parts to dry using small pieces of wire.Etch primer works best with a very thin coating. Etch primer can alter the interference fit of bearing seats and bores for bushes and these are best masked off and not primed or painted. Axles are best masked off and later coated with a dry lubricant such as Rocol Oxylube. You’ll now have to decide when best to prime, whether part by part or by sub-assembly. Although Armortek models can be built straight out of the box, most builders test fit parts and assemblies. Priming every part gives the best protection but might require some additional easing on assembly. Priming by sub-assembly is less work but at least ensure that all aluminium/steel interfaces are protected.

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The tracks take the most abuse and will be vulnerable to corrosion, particularly on the track pins if left damp for long periods after use. Some argue that priming and painting tracks is unnecessary because wear quickly removes the protection. Others choose to prime and paint all the track components both to protect them and achieve a realistic finish. In practice, most of the prime and paint remain on the tracks after use. There is a separate Knowledge Base Topic on priming and painting tracks here:

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Step 3 - Final Paint. The model is now ready for the base colour coat and any camouflage and markings required. There is no restriction on type of paint or method of application, whether by brush, rattle can or airbrush. Choices will be influenced by availability, cost, ease of application and how dedicated you are to achieving a particular type of finish. You can paint at any stage but it is probably easiest to apply the base coat before final assembly and installation of motion packs, separating major assemblies such as running gear, turrets and hulls.

Scale Considerations – the “artistic” bit.

Surface Effects. You may wish to add surface effects to represent rolled or cast armour plate and, where appropriate to represent German Zimmerit anti-magnetic mine paste. These are best added after priming and any gaps in coverage can be re-coated.

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There is a Knowledge Base Topic on creating surface effects and welds here:

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German WW2 Primers. German WW2 AFVs and guns were mostly primed with a red colour, RAL 8012 Rot (Rotbraun). Some builders choose to overspray the etch prime with red before painting the base colour.

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Applying a paint scheme. Painting is your personal stamp on the model. Some choose an entirely imaginary paint scheme which satisfies the builder. Others select a generic but authentic historic scheme as reference and some go as far as replicating a specific and historically accurate example basing their scheme on contemporary references and photos. These notes are a basic introduction to paint types, sources of information, methods of application.

Paint types. There is no restriction on the type of paint used. Cellulose is probably the most robust and is a good choice for a model which will get heavy use. For the ultimate in robustness, one Armortek builder has even had his tank powder coated. Most builders however use readily available acrylics, lacquers and enamels intended for plastic kits. If you’re brush painting or don’t intend to weather the finish, enamels are a good choice, particularly if you’re familiar with them. Acrylics are increasingly popular. They do require airbrushing (see below) but the choice of colours is huge, they are flexible and less toxic to use and ultimately provide a harder finish. There is one further advantage. If you intend to add weathering effects, acrylics are a wise choice for the base coat. Oils and enamel based weathering products can be overpainted, adjusted and removed without disturbing the acrylic paint underneath. The two Knowledge Base Topics on Weathering are here:

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Airbrushing. Model paints typically come in very small quantities and don’t readily support brush painting. With an airbrush however, the coverage surprisingly large. It’s possible to cover an entire model with as little as five or six 10ml pots. An airbrush isn’t necessary but is a good investment for Armortek builders. There is a Knowledge Base Topic on Choosing an Airbrush here:

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For a BASIC model, the simplest solution is to go with the appropriate model paints or ones from a specialist supplier. As a lead in to more ADVANCED colour schemes, the following is a starting point.

Sources of colour information. AFV colour is a good subject for the insomniac and obsessive/delusional. It is a minefield of instant experts and dodgy data. Finding reliable information is not easy. With some notable exceptions such as Tiger 131 at Bovington, very few museum exhibits retain original paint. Where it survives, the colours will have faded and altered with time. Plastic modellers lighten colours to offset the supposed “scale effect” (paint appearing darker on smaller scales) and there are trendy techniques such as “colour modulation”. Some model paint suppliers adjust their paints to accommodate these fads. The most reliable sources are the original specifications and colour chips used to produce the paint. Fortunately, these are increasingly available in high fidelity publications. The following contain accurate colour chips and are reliable:
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From these references it’s possible to work out the correct colours for a scheme seen on a photo or verify schemes from other sources such as plastic kit instructions. With an accurate paint chip, the ultimate accuracy can be achieved by having paint mixed to order. See for example here (scroll down):

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Summary. Final thoughts. Priming protects your investment, prime everything as you go along, paint is your chance to personalise your model and show your expertise. The extra detail of surface textures and weathering aren’t necessary but elevate a model and give it character and context. For some, the research is everything, for others, painting is all that stands between them and operating the model. Above all, painting is a process to enjoy.
Armortek

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