Weathering with an airbrush: If you’re looking to give your freight cars and locomotives a general coat of grime in relatively little time, try using an airbrush and thinned acrylic paints.
My first step on this Athearn HO scale 54-foot covered hopper kit was to spray the entire car with thinned Polly Scale Reefer White (1 part paint to 9 parts 70 percent isopropyl alcohol). I built up the color in layers, aiming for a slightly faded look.
After the white had dried, I sprayed the car with the same ratio of Polly Scale Railroad Tie Brown. I moved the airbrush in a vertical motion, keeping it parallel with the exterior posts,.
![An image of an airbrush being used on a blue model boxcar](https://www.trains.com/wp-content/uploads/2022/12/MRR-weather-with-an-airbrush-04.jpg)
Some of you may be wondering why I recommend using acrylic paints. Well, it’s for the next step. After I applied the Railroad Tie Brown, I dipped a cotton swab in Windex and carefully wiped the paint off the faces of the exterior posts.
![Weather with an airbrush: A cotton swab is used along the side of a blue model boxcar against a white background.](https://www.trains.com/wp-content/uploads/2022/12/MRR-weather-with-an-airbrush-03.jpg)
These posts tend to collect less dirt than the car sides. This subtle bit of reverse weathering is an easy way to give your exterior-post freight cars some added realism.
I then shifted my attention to the slope sheets. Finally, I used thinned Polly Scale Steam Power Black to simulate the oil and grease streaks on the car ends. The key here is to keep the streaks vertical and parallel.
![Weather with an airbrush: A airbrush is used along the backside of a blue model boxcar.](https://www.trains.com/wp-content/uploads/2022/12/MRR-weather-with-an-airbrush-02.jpg)
With the weathering complete, I sprayed the carbody with Polly Scale Gloss Finish in preparation for decal-ing. Afterward, I sprayed the entire model with the firm’s Satin Finish.