Weathering with Chalks

If you are following along in our bone yard project, or just looking for ways to add some age to your models, there is no easier way to get started weathering than with chalks. Weathering chalks and powders are available in several forms and many colors. They can be used in a variety of ways for different effects. Best of all, they are completely reversible if you don’t like your first attempts.

Chalk or Powder


Both powdered and stick chalks have their advantages and can both be used effectively to weather your models.

The chalks we use to weather our models come in two different forms. Several companies market powdered chalks in a great variety of earthy and gray colors perfect for modeling. If your local hobby shop doesn’t already have these, they can probably look them up and order some for you. These powders have an advantage in that they come ready to use. All you need is a brush and a model!

You can also find suitable materials in your local art or craft supply store. These artists’ chalks come in stick form and are usually sold in sets. Stick with earth tones, black and grays for most weathering applications, but you may find use for some traditional colors too, like creating a faded paint look.

Generally, these sticks are less expensive than the powders and craft stores will often have sales and discounts to further lower the prices. You can make your own powder from the sticks by rubbing them on a scrap of fine-grit sand paper. Then you only make what you need for a project and the rest stays “spill proof.” The sticks can also be applied directly to the models. This is very useful if you want to make a fine detail.

Clean Before You Weather

Dusting a model with weathering chalks is just like dusting a crime scene for fingerprints. Especially when contrasted with a high gloss surface like you’ll find on many models, the chalks will stick instantly to fingerprints and any other oily spots on the model. We’d all like to be able to identify our handiwork – but not like this!


A quick cleaning will remove any dirt and fingerprints before weathering.

Before weathering, take a few moments to wipe down the car. Spay just a little window cleaner or other mild cleaner on a cloth or paper towel and clean the entire carbody. Be gentle – you only want to take off fingerprints, not paint.

Wearing a pair of disposable gloves while you work will not only keep your model fingerprint free, it will also make your personal cleanup much easier. Remember, fingerprints left after the chalk is applied will show just as easily as those that were there before.

Applying the Chalks

An old paintbrush makes the perfect tool for applying your weathering chalks. Just remember, once used for chalk it can no longer be used for paint.

half weathered

Chalks have been applied to the left half of this caboose. Before this the entire car was given a weathering wash and the trucks and wheels painted with grimy black paint. Layering creates even more effective results.

Pick up some powder on the bristles and gently brush it onto the model. Where and how you apply the chalk will determine the effects. It is best to study pictures of real trains to get a feel for what looks right. Feel free to mix and blend colors to create new shades.

No two cars are the same, but you will notice several common traits. Here are a few:

  • For rust, soot and grime that starts on the roof and works its way down the car, apply powder near the top of the sides and brush in a downward motion. Streaks should be vertical and heavier at the top than the bottom. Don’t forget the roof and the ends!
  • Dust and dirt kicked up from the wheels will create a “bow wave” effect on locomotives and cars. concentrate these colors around the trucks, lower carbody details and the lower sills.
  • On ends of cars where the wheels are exposed like hoppers and tank cars (containers carried in the bottom wells of double-stacks also show this effect) kicked up dirt creates distinctive parallel streaks. Start at the bottom and grow thinner as you go up, keeping the streaks in line with the wheel treads.
  • On “ribbed side” or exterior-post cars, dirt is often washed off the posts and collects more on the “panels” in between.

You can easily blend multiple colors to create new shades or more effects as seen here. We’ll show the rest of the steps in making this corrugated metal siding in a few weeks.

In general, if you think about what the equipment is exposed to, you can see there is some logic to how a car gets dirty. Older cars will likely be more weathered than newer equipment. Steam era equipment is much more likely to show signs of dark soot on roofs than in the diesel era. Dirt gets kicked up from the ground and washed down by water. Follow your instincts, use some pictures for reference, and your models will show it.

To apply more exact effects, sharpen the tip of a chalk stick and apply directly to the car. This can be very useful when trying to recreate streaks of rust from specific details on the car for example.


Not happy with your first attempt? No problem! Dampen a paper towel with water and simply wipe off your weathering. Let the car dry completely and try again. You may have to work a little to get all of the chalk out of the nooks and crannies – then again you may decide you like the look and just leave it.

Fixing the Chalk

If you are happy with the results, you’ll want to protect them. You can of course run your cars without sealing the weathering – just be careful how you handle them so you don’t leave fingerprints or remove the chalk.


Seal the chalk with a clear flat finish sprayed gently from above.

If you want to seal things, then you’ll need to apply a clear coat of flat finish to the entire model. This can be done with an airbrush or using spray cans. In either case, there is an art to applying this finish.

If you try to spray directly onto the car, you will wash off all of the chalk. Apply the spray from a greater distance so the clear finish is nearly dry when it hits the model. Also, spray down onto the model, allowing gravity to work with you. Turn the model as necessary to do all of the sides and the roof.

If you find you’ve still washed off too much of the chalk, you can go back and reapply. With the flat finish in place, the chalk will likely bond better the second time around. You can also plan ahead and put on a little more chalk than you want, knowing you’ll likely lose some of it in the sealing process.

Finished model

Faded lettering, weathering washes and finally chalks were all combined to turn this Pennsy tender into a storage shed. We’ll cover this project in greater detail in coming weeks.

While we’ve talked about weathering patterns on railroad equipment, chalks can also be used on buildings, accessories and anything else you’d like to weather. The options are endless and the process the same. As you get more comfortable working with the chalks, you can get quite creative with your techniques knowing a correction is just a paper towel away.

You can also mix your chalk applications with other weathering techniques on the same model like those found on these pages.

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