Painting A Scale Model

Painting A Scale Model

Painting A Scale Model

By Fred Cronenwett | [email protected]

As seen in the August 2022 issue of Model Aviation.

The B-29 wing panel is installed on the fixture for painting. The eyelet on the far right side will be used to hang it during the drying process. The B-29 wing panel is installed on the fixture for painting. The eyelet on the far right side will be used to hang it during the drying process.

AFTER A BALSA MODEL structure is complete and it has been sanded, it’s time to cover and paint it so that it is fuelproof. You can use iron-on film, but I will discuss what is involved with painting a model.

I like to fiberglass models then paint them, but the challenge is finding fuelproof paint. The clear coat that I have begun to use is Klass Kote Clear. Using multiple paint samples, I have proven to myself that Klass Kote Clear can be sprayed on top of hardware store spray paint, latex house paint, and, of course, Klass Kote color coats.

Because I build with foam wings that have a balsa skin, I don’t have any open structure on my models. However, if you do have an open structure, you have to use an iron-on fabric that can be painted, such as Sig Koverall or Oratex, which is available from Balsa USA.

There is no easy way around this. If you use a high-volume, low-pressure (HVLP) air gun, you will need a large air compressor. I use a 20-gallon air compressor. The problem is that once you get it up to sufficient pressure, you can quickly lower the main tank pressure to the point where the compressor has to turn on again to keep up with the HVLP air gun. If the tank is too small, it won’t keep up with the air gun. My 20-gallon compressor has a difficult time keeping up, but I can get the paint job done if I let the tank come back up to pressure.

The HVLP air gun also requires a pressure regulator and a water trap. The compressor’s main tank will be at a higher pressure than what you need, so the pressure regulator on the air gun controls how much pressure it uses. The air gun is typically at 30 psi, while the main tank could be as high as 125 psi. The pressure required for the air gun will vary based upon the paint you are using.

You also need space to paint the model then allow it to dry for several days without being touched. I paint outside (which is not ideal), and then I hang the items in the shed to dry for several days so that the smell of the new paint does not get into the house. Some people paint in the garage, while others might have access to a paint booth.

The other challenge is that you need to somehow hold the part then paint it. While the paint is wet, it needs to be put into a spot where it can dry for several days without anything touching the surface.

If you touch a model painted with Klass Kote paint too early, it might not be fully cured and you will leave finger smudges on the surface. See the picture of the fixture that I made for the B-29 wing panels.

Test Panel

Before you spend a lot of time on an actual model, do a test panel of the covering material, primer, paint, scale details, and clear coat to see if that is going to work for you. I made some mistakes doing my test panel with the Klass Kote paints and have changed my setup so that I don’t make similar mistakes.

The stabilizer in the photograph was my test panel to try out the Klass Kote primer and paint system. The balsa part is fully skinned and was fiberglassed. I used the white Klass Kote primer, and then painted the panel with Klass Kote aluminum paint. The ink lines were done with Koh-I-Noor technical ink pens.

If you have never applied ink lines using these pens, I would suggest doing it on a test panel first so that when you work on the model it will come out as you want it to. Use a straightedge with a cork backing so that the ruler itself does not touch the surface. You don’t want the ink to get under the ruler.

This paint sample was done with Klass Kote primer and Klass Kote aluminum paint. The ink lines and vinyl decals have also been applied. This paint sample was done with Klass Kote primer and Klass Kote aluminum paint. The ink lines and vinyl decals have also been applied.

Covering Options

My first covering choice is to use ZAP Z-Poxy Finishing Resin and 3/4-ounce fiberglass cloth over the balsa structure. After the first layer of resin and fiberglass cloth has been applied and sanded out, I then put another coat of finishing resin over that.

If you have any areas that need additional structural strength, you can put two or more layers of fiberglass cloth on the structure. Put those down first in the areas that need extra reinforcement, and then put the overall fiberglass cloth down over that.

Refer to the video on my YouTube channel about how to fiberglass a balsa model. The link is listed in "Sources."

Primer Color

The color of the primer that you use makes a difference. There are typically two colors available: white and gray. If your model is going to be a lighter color, use the white primer.

Look at your paint scheme and figure out what color of primer you should use and in what order you will apply the paint. Start with the lighter colors then apply the darker colors over that.

Paint Options

There are many options available, but the two that I have used are Klass Kote and latex house paint. The latex house paint is not fuelproof. Some of the other fuelproof paints that I have used in the past are no longer available.

Following are the steps to use when painting a model.

1. Cover the fiberglass-clothed model with two coats of finishing resin.

2. Put down a coat of primer.

3. Paint the base coat over the entire model.

4. Paint the trim colors on top of the base coat.

5. Apply the ink lines as desired.

6. Apply the decals or any other markings.

7. Apply a clear coat over the entire model.

Latex house paint is easy to handle because it’s simple to clean it up from the air gun, but I needed a way to have a fuelproof clear coat over latex paint. I took a chance with a test panel that was painted with a water-based latex paint.

I put Klass Kote Clear on top of the latex house paint. There was not a negative reaction between the dry, water-based latex paint and the Klass Kote Clear. In fact, I have tried several combinations without any problems, including using typical hardware store spray paint with Klass Kote Clear over it.

If you have a small model, you could fiberglass it, put a coat of spray primer down, and spray paint it. Let that dry then put a coat of Klass Kote Clear over that and you are done.

2022 Contest Calendar

This was written as the flying season was just getting started. There are new exhibits at the National Model Aviation Museum in Muncie, Indiana.

It will be interesting to see them firsthand when I go to the Control Line (CL) Scale Nats in July.

Upcoming events on the contest calendar include:

  • All Buder Park Flying Day: August 27, 2022; Buder Park, Valley Park, Missouri
  • Midwest Regional CL Championships: September 3-4, 2022; Aurora, Illinois
  • National Association of Scale Aeromodelers (NASA) CL Scale Classic, September 10, 2022; Muncie, Indiana
  • Broken Arrow CL Stunt & Scale Contest: September 17-18, 2022; Buder Park, Valley Park, Missouri

Land softly!

SOURCES:

Klass Kote

(612) 243-1234

www.klasskote.com

Koh-I-Noor USA

(800) 628-1910

www.kohinoorusa.com

Fiberglassing Model Airplanes

YouTube

https://youtu.be/Z031C5_RwMU

Lafayette Esquadrille Control Line Club

www.lafayetteesquadrillecl.wordpress.com

ZAP Adhesives

www.towerhobbies.com

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