How to Paint Radial Engines: Legacy Kits
Updated: Nov 13, 2021
Warbirds are exciting aircraft to build because they present many opportunities for detailing. Radial engines anyone? Radial engines derive their name from the circular arrangement of their cylinders about a central crankshaft. The engines have large "clock-faces" and what they lack in aerodynamics, they make up for in simplicity: they can be cooled by exposing that clock-face to oncoming air. From a modeling perspective, that means we can see radial engines sitting inside their cowling and therefore, we need to paint them.
Since I have returned to modeling I have completed several radial engine kits, mostly 1/48 scale World War II fighter aircraft, and it turns out that they were all tooled in the 60s and 70s. These legacy kits can be excellent for new modelers because they are simple and cheap. Unfortunately, by today's standards this also means their engines have limited detail.
But no need to despair! In this post, I will show you how to get the most out of these legacy engines using easy painting techniques and a bit of patience. Let's turn the starter switch shall we?
So we don't get overwhelmed, the details that I go through in the next section can be thought of in terms of three core components:
Paint base colors
Enhance the details
Because this post is aimed at beginners, I thought I would hand paint the engine. It also helps that the engine is small enough, textured enough, and hidden enough that we won't need to worry too much about leaving brush strokes. For paint, I used Tamiya acrylics, a varnish from Vallejo, and a homemade oil wash. Here is everything:
The engine comes from Tamiya's A6M2 Type 21 Zero in 1/48th scale. This kit was originally tooled in the 70s.
Tamiya paints are meant for airbrushing. They dry too fast and don't self-level well. To accommodate for this, I thinned my Tamiya paints with a few drops of water and made use of their retarder product. Collectively, these two actions should improve application and reduce the chance of brush strokes.
Vallejo's Gloss Vanish is used to protect our base paint and detail work from the weathering process. For protective coats, it is important to use a dissimilar medium (acrylic, enamel, lacquer) from the type of weathering products to follow.
Homemade oil wash might sound fancy, but it is a very simple thing to make. Just take a dab or two of oil paint (from your local art store) and mix it with plenty of mineral spirits so that it has a thin consistency. I made mine with equal parts Ivory Black, Burnt Umber, and Yellow Ochre from Winsor & Newton's Winton Oil Colour line. When the wash is applied, it will flow into the recesses and bring out details. Because the oil paint is very slow to dry, it is easy to wipe away any excess with a brush dampened with mineral spirits.
Engines are usually metallic colored and metallic paints usually look nicer if they are applied over a black base. In the first photo, I have brushed on a few thin layers of Tamiya's XF-1 Flat Black that was thinned with water and a drop or two of retarder. These coats don't need to be perfect, they just need to provide general coverage to build on.
After the black was laid down and dried, I added two coats of XF-16 Flat Aluminum, again thinned with water and a few drops of retarder.
The last base color was X-10 Gun Metal, and because it covers a smaller area, I can usually paint it straight from the bottle. Don't be afraid to fix any messy areas with more XF-16 Flat Aluminum or X-10 Gun Metal as needed.
You might be tempted to stop painting here, but there is still more we can do. We can start detailing! This engine had some raised detail in the middle of the top layer of cylinders. I decided to paint this XF-6 Copper, and added X-12 Gold Leaf to what looked like wire or hose molding. Both of these were taken straight from the bottle. I'm not sure if these are realistic colors to use, but I like to add visual interest. Call it a "modeler's license".
Next it was time to add a wash to the entire engine. But first I had to protect our work with two thin coats of the gloss varnish, each thinned 50/50 with water. Once the varnish has dried, I added the oil wash over the entire engine and cleaned up the excess with mineral spirits. The oil wash adds depth to the engine by flowing into the recesses.
A final step can be taken whereby the slightest amount of X-11 Chrome Silver is brushed on to elevated details. If the wash added depth, the X-11 Chrome adds height.
And that is how you bring a legacy radial engine to life!
About that clock-face
So how much of this detail do we end up seeing? Well, that depends. First, how big is the propeller spinner, and second, how deep is the engine set in the cowling. Here is what the Sakae engine looks like inside of the A6M2's work in progress cowling.
Meh. Such is the life of a modeler. Sometimes paint and detail things that only we know are there!
It is a fact, newer kits have more radial engine detail. But that doesn't mean you can't bring legacy kit radial engines to life. Furthermore, if you are new to the hobby, these engines provide a great testing ground for new techniques. And you don't need to sweat the details too much. After all, any misstep can be easily hidden from view.
Once you are comfortable with the techniques discussed above, consider taking your engines to new heights on one of these three paths:
Get a newer kit
Add some scratch-building or wiring
Experiment with photo-etch sets. These can be found in the aftermarket or increasingly issued with newer tool kits themselves
I know I will.
Thanks for reading,
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