Month: March 2025

Painting freight cars

Step-by-step on painting freight cars in batches with airbrush and acrylic colors

Painting freight cars: I recently purchased a few inexpensive, older Roundhouse boxcars and Athearn mechanical reefers on eBay to repaint and letter for the Southern Pacific Railroad and Southern Pacific Fruit Express.

Painting N scale freight cars, spray booth

For this project, I used the discontinued Polly Scale Boxcar Red – yes, I still have a bottle from 2007 – along with Vallejo acrylic paints. Unfortunately, the Polly Scale paint had aged poorly and clogged the airbrush, regardless of how much I thinned it.

Boxcar Red color with Vallejo acrylic paint

To achieve a convincing “Boxcar Red” color, I mixed equal parts of Vallejo Camouflage Medium Brown (71.038) and Vallejo Brown RLM26 (71.105).

Painting an N scale undecorated boxcar with Vallejo colors

Painting freight cars in batches

I prefer to paint in batches to make the most of my effort.

This time, I prepared three 2-bay covered hoppers, four boxcars, three 57′ mechanical reefers (to be painted and lettered for SPFE – Southern Pacific Fruit Express), and one old, inexpensive caboose.

57′ Mechanical Reefers

Soaking the boxcar shell in 99% isopropyl alcohol for at least three days significantly simplifies the paint removal process. As shown above, the paint practically lifts off the shell!

I washed the car with warm water and a drop of soap to remove fingerprints or oils, wearing plastic gloves. I used a soft toothbrush.

Washing the car shell with warm water and soap.

Once completely dry, I sprayed a coat of Vallejo acrylic White Primer using an airbrush. I used a few drops of the Vallejo Flow Improver.

Shell painted with Vallejo White Primer

After painting the roof white (Vallejo White 71.001), I masked it off and sprayed the reefer with Vallejo Orange (71.083).

Painting N scale freight cars: SPFE 57' mechanical reefer

Then I carefully and slowly removed the masking tape

Removing the masking tape
Removing the masking tape

Here is future SPFE 459273.

Painting N scale freight cars: 57' SPFE Reefer ready for gloss varnish coat.

Two other 57′ SPFE Reefers will be painted with black ends. I properly masked the car and sprayed some Tamiya XF-1 black thinned 3:2 with Vallejo Airbrush Thinner.

Painting N scale freight cars: Airbrush colors and auxiliaries

This time I experimented with a few drops of Vallejo Airbrush Flow Improver.

57' SPFE Reefer with black painted ends
Two 57' SPFE Reefers with black painted ends

Reefers are now ready for a coat of gloss varnish. This layer provides a smooth surface for easier decal application, helping the waterslide decals adhere properly without silvering.

57' SPFE Reefer coated with gloss clear paint.

Lettering (applying waterslide decals)

To apply the decals, I first cut them out carefully, staying close to the printed edges for a clean finish.

Painting N scale freight cars: PFE Reefers decals sheet

I soaked the decals in warm water for 10–15 seconds, just enough to loosen them from the backing paper without over-soaking. I gently slid the decal onto the car, positioning it with a soft brush or tweezers.

For tricky areas, I used Microscale Micro Set decal-setting solution to help the decal conform to surface details like rivets or panel lines. For the most difficult irregular surfaces I used Microscale Micro Sol, to soften the decals for a few seconds before applying them.

57' SPFE Reefer ready to be lettered with 60-250 Microscale decals sheet

Once positioned, I lightly dabbed with a cotton swab or soft cloth to remove excess water and ensure the decal sits flush.

57' SPFE Reefer lettering
Cars lettering: SP Hydra Cushion 50' boxcars

I allowed the decals to dry completely before applying a final coat of clear matte to seal and protect them.

Decals sealed with a coat of flat clear paint.

After the flat clear coat dried, I proceeded with installing Micro Trains Line 1015 body-mount couplers. I drilled a hole in the metal chassis e screwed the couplers down.

Installing MTL-1015 couplers
Painting freight cars, Hydra-Cushion SP boxcars

Painting undecorated cars can be a daunting task, requiring skills like airbrushing and decaling. However, finding a cheap undecorated car to experiment with and refine these techniques is fairly easy.

Moreover, if you have a decorated car that you never liked, it could be a good candidate for this project.

N Scale Diorama: Ballast

Part I: Building an N scale diorama to test my modeling skills

Before committing to adding scenery to the layout, I want to build an N scale diorama featuring a section of track with ballast, a road, vegetation, and a few details.

It doesn’t have to be perfect, but it should serve as a test of my modeling skills after a 15-year hiatus from model railroading.

Basic Trackwork

I glued a strip of EVA foam to a piece of plywood, then secured a section of Micro Engineering Code 55 flex track, which I’ll be using on the layout.

N scale diorama, EVA foam and flextrack glued

Painting

Next, I painted the track Railroad Tie Brown. I had two Polly Scale bottles from the late 2000s, and both held up surprisingly well.

Polly Scale Railroad Tie Brown paint
Track painted with an airbrush

Ballast

The next step was ballasting the track using Woodland Scenics Buff B1373. I used a technique I have relied on for years – first spreading the ballast over the track, then using both a soft brush and my fingers to evenly distribute it between the ties.

N scale diorama, ballasting the track

Then, I misted the ballasted track with a 50/50 mix of water and 99.9% isopropyl alcohol, letting it soak for a minute. After that, I used a syringe to apply a 50/50 mix of water and matte medium, slowly sliding it along the rails to glue down the ballast.

I used Liquitex Matte Medium, following the advice of YouTuber Boomer Diorama.

Woodland Scenics Fine Ballast and Liquited Matte Medium.
Ballast soaked with glue (50/50 water and Liquitex Matte Medium)

Here is the result of the N scale diorama with ballast after the glue have dried.

N scale diorama: ballasted track

Weathering the N scale diorama track

For increased realism, I mixed dark brown powdered pigments with plaster of Paris in a 50/50 ratio to weather the area between the rails. Using a brush, I evenly distributed the mixture along the track with several strokes.

Powdered pigments
Spreading the powdered pigments and plaster of Paris mix with a brush.

Then, I misted the track with water, allowing the plaster to react and permanently set the weathering in place.

Misting the track to set the weathering powders

Starting Over the N Scale Diorama

Well, I wasn’t happy with the result. The ballast wasn’t evenly distributed, and some grains ended up on top of the ties. I also applied too much matte medium, which left a visible film on the rail sides. Long story short – it was a failure.

And I’m glad I failed. I’d rather make mistakes on a small N scale diorama than on the actual layout. That’s exactly why I built it – to test my skills, learn, and improve. So, I scraped off the ballast, removed the track, and started over.

Referring to other model railroads

I looked through photos of my previous layouts, and to my surprise, the ballast work wasn’t as good as I remembered. It wasn’t terrible, but I now aim for better results. So, I started studying photos and videos of other modelers’ layouts and sought advice on online forums.

One key takeaway was to use less ballast and spread it as evenly as possible. A helpful trick is tapping the tops of the rails with the same teaspoon used to pour the ballast – this helps it settle and compact for a more realistic finish.

I removed the EVA foam and trimmed it to be slightly narrower. Then, I glued it back down and secured the flex track with white glue.

N scale diorama: starting over with ballast.
A much better ballasting job
N scale diorama, ballast laid.

Glueing down the ballast

The track looks a lot better now. I mist the ballast with the same 50/50 water and alcohol mix, and let it soaked. This time I used another method for glueing the ballast, again thanks to an online model railroading forum member. They suggested to mist the ballast, instead of using a pipette or syringe. I used the same 50/50 water and matte medium mix.

Misting the ballast with 50/50 water and matte medium mix

Then, I let it dry for a day. It looks much better than the first attempt.

N scale diorama, a much better ballasting job.

Weathering, Take two.

This time I used black powdered pigments, as brown blends better when mixed with yellow and it more suited for sidings or spurs. 50/50 mixed with plaster of Paris.

Black powdered pigments and plaster of Paris
Black powdered pigments and plaster of Paris mixed with a brush

With the same technique, I distributed the pigments between the rails with a flat brush.

Then, I misted the diorama with water, allowing the Plaster of Paris in the pigment mix to bond and permanently fix the track weathering.

Here is the final result after the pigments dried and the rail heads were cleaned. Maybe I could have gone lighter with the soot and grease weathering between the rails or used a 30/70 pigment-to-plaster mix instead of 50/50.

Ballast and track weathering complete
N scale diorama: ballast complete, track weathered and an SP Intermountain SD45-T2

Model Railroad Cars Weight

How much should model railroad cars weigh? Let’s explore NMRA Recommended Practice 20

A proper model railroad cars weight plays a key role in ensuring smooth operations, especially on tight curves and uneven track sections where some cars may derail. Also, properly weighted cars significantly improve realistic operations, especially when it comes to coupling and uncoupling.

Model railroad cars weight
Using 5-gram (0.18 oz) tire balancing weights to add weight to a covered hopper.

The ideal weight for each car depends on its length. Using NMRA standards, particularly RP-20, you can calculate the optimal weight for any car and adjust it if needed by adding extra weight.

How to calculate weight

Here’s the formula for determining the recommended weight of a model train car:

Recommended weight = Initial weight + (Car length × Additional weight per unit length)

Let’s break it down with a practical example.

The image above shows an N scale Atlas ACF 2-bay covered hopper. It weighs 15 grams (including trucks, wheels, couplers, and a factory-installed weight) and measures 70 mm in length. According to the NMRA RP-20 standards, the initial weight for N scale is 14.17 grams (0.5 oz). The additional weight is calculated as 0.15 oz per inch (equivalent to 4.25 grams per 25.4 mm, or approximately 0.167 grams per mm).

  • Initial weight = 14.17 g
  • Car length = 70 mm
  • Additional weight = 70 mm × 0.167 g/mm = 11.69 g

Total Recommended Weight:

Total Weight = 14.17 g + 11.69 g = 25.86 g

A 15 g, 70mm car should weigh almost 26 g, so I need to add 10 g. Tire balancing stick-on weights are an excellent choice for adding weight. They’re affordable, easy to find, and readily available. My approach involves removing the car shell, identifying suitable spots to place the weights, and securing them with adhesive.

Covered hopper with additional weight, now correctly measuring 26 grams.

Adding weight to model railroad cars requires a bit of extra effort, but it pays off in the long run.

Using 5-gram (0.18 oz) tire balancing weights to add weight to a boxcar chassis.