I use solvent and water-based paints on the same casting. This way I can apply an initial wash with the solvent paint then after a few minutes paint the details with the water based. If I were to use only one type I would have to allow 24 hours for the initial wash to cure before proceeding to avoid mixing of the colors. In addition, solvent based paints just do a better job of handling the initial wash that will be described in detail below. Water based paints are fine for the details on top. If you cannot locate the Floquil and Polly Scale brands of paints I recommend at a store near you, try micromark.com, a very reliable hobby tools and supply company.

I use mostly Rembrandt and Winsor & Newton brands of fine artists pastel chalk sticks. They are easy to find at better arts supply stores. They should be able to special order them for you if not stocked. Also try dickblick.com, a mail order supplier of fine art materials, they carry a wide range of sticks. I have used both Sennelier and Schmincke brands with equal success.The point here is to use high quality sticks with intense pigments. Stay away from sets and buy the individual sticks. The sets include colors you will never use. As mentioned earlier I avoid the weathering powders and pigments sold in our hobby. They just don't do what I want them to.

the orange family
used for rust

Raw Umber
Gold Ochre
Yellow Ochre
Flesh Ochre
Light Ochre
Burnt Umber

Rembrandt sticks are the best choice for brown colors

Red-Brown Ochre
English Red Deep
Burnt Sienna
Raw Sienna
Winsor Red
Winsor Orange

W/N sticks are the best choice for rust colors

Remove any minimal flash from each casting using fine files and a No. 11 blade. Drill a shallow hole in the bottom and shove a scrap of wood in to create a handle to use while painting and weathering the castings. I imbed the sticks into blocks of non-drying clay to hold the castings while the paint is drying. Prepare large groups of castings in this manner so they may be painted all at once.

The tools of the trade. A good selection includes No. 11 and 16 blades for scraping, files for smoothing and shaping, sprue nippers and tweezers for cleaning. You will find my castings are ultra clean right out of the box and I take great pride in them. They will not require much cleanup ahead of painting and weathering.

Apply random light washes of thinned down Floquil colors like Earth, Roof Brown, Grime, Rail Brown, Grimy Black, Concrete, and Mud to the wooden portions of these types of resin castings. Thin the paint down by dipping your brush first into the full strength paint then immediately into Dio-Sol. Dab it randomly onto the casting. (Do not brush.) Notice inn the picture to the right how the wash really brings out the texture of the castings.

Be neat but do not attempt to keep the stain off of the smaller details that are not wooden. (Like tools, bottles, etc…) These will be painted later. Make sure to get the stain into all of the crevices. Use a soft rounded brush and begin with the darker colors. Give quick random splashes across the surface then continue with lighter colors until the wooden portion of the castings are completely covered with a mottled layer of stain. Once completed set these castings aside allowing the paint to dry. I model on a glass surface so I can swirl and mix paint colors freely directly on my workbench like an artists palette. This provides a tremendous amount of flexibility in how I mix my colors keeping everything natural in appearance.

Lay all of the castings out to be painted. Many can be done at once. This method is much faster than one casting at a time. Open Floquil colors like Brass, Gunmetal, Old Silver, Graphite, Rust, and Dark Rust. Using a very small detail brush, paint a few metal details on each of the castings with Brass, then come back and paint some more with Gunmetal, then with Old Silver, etc… until all of the metal details on every casting is complete.

The dark rust paint is a 50/50 mixture of Rust and Roof Brown, a favorite choice of mine. Now open Floquil colors like Reefer Grey, Depot Buff, Boxcar Red, Coach Green, Roof Brown, and paint the remaining details in the same manner. Keep a dull No. 16 blade handy so that when you get some paint where you do not wish it to be, you can scrape it away before it dries. Add spots of random color with red or green to a small bottle, can, or random bit of trash. Touch up any wood areas with the “wood” stains. Vary the color used from piece to piece. Paint the bottle tops silver. Now give the entire casting a very light wash of alcohol and chalk powder using technique number 1 as described below.

I use a small tray like the one shown to keep my chalk sticks in. I freely mix and blend them quite randomly while I work and having a good assortment of colors available makes this possible. I use solvent or plain rubbing alcohol to fix the powder to the casting. Since these castings are not handled once installed, this fixative works fine. If you want to weather rolling stock you would need to use a chalk fixative made specifically for the purpose.

There are two closely related techniques used to apply chalk powder. Technique number 1 applies a light layer and is great for dulling and smoothing out the surface of castings like those finished above. This is that homogenizing and blending layer mentioned earlier. It can also be used to apply a light layer of rust and gunk. The second technique applies a heavy layer of rusty grimy texture.

The lowly oil drum is the perfect casting to use and describe the two different techniques available to apply chalk texture. Experiment with them and see how the results differ. Both methods are outlined in detail next. Try using the two different chalk techniques directly on some drums without applying a primary base color first. Then on others apply a base coat using various colors of Floquil like Reefer Grey, Mud, Antique White, or any dull green, red, or orange. Then try the two techniques. Dull and muddy any bright base colors. Although they may be prototypical, they tend to stand out on models and always look like cheap plastic. By layering the colors you are creating depth. Adding the chalk creates texture. This combination of depth and texture is an unbeatable combination.

Technique Number 1
Dip the very tip of a soft rounded brush into plain rubbing alcohol then remove most of the liquid from the brush. Now apply this to the casting so it is just barely wet. Use a second dry brush and apply the chalk powder at random. Repeat applying the alcohol/chalk powder until the desired look is achieved. Mixing dark and light colors with a hint of black and grey is a terrific combination. Apply the chalk with a dry brush as a wet brush will leave streaks and marks. The application must be totally random to achieve a mottled looking finish. Never brush, always blot.

Technique Number 2
This method applies a much heavier layer of “rust”. Use it on castings like any deteriorated oil drum, old boilers, misc junk, etc... Allow only a hint of the original resin color to show through. Use the tip of a single edge blade to scoop up and dump a small amount of dry powdered chalk directly onto the casting. Use several different colors, dark and light at random, and mix them up. Now dip the tip of a small stiff square brush or a stenciling brush into plain rubbing alcohol, or for an even darker final color, dip it into the dark rust floquil paint mixture. Remove most of the alcohol or paint onto a rag then dab and blot the brush directly on top of the chalk powder. Re–dip the brush as needed and make sure to move it around randomly. If you use too much alcohol or paint the chalk will totally dissolve ruining the effect. Dab just a little at a time and build up the alcohol or dark rust slowly on top of the powder. This will result in a casting with a rough layer of mottled chalk on its surface – it looks just like rust. Experiment with this technique until you get the hang of it. You must use a brush with stiff bristles. If the brush is too soft it will spoil the desired effect. If you are unhappy with the finished results just swish the casting around in some Dio–Sol to remove the weathering and try again!

The techniques and color choices combine nicely to produce rusty texture on the boiler (gunmetal base) and the wooden aged texture on the water tank. Chalk also gives that dry and dusty appearance on the finished model.

Here is a second example of rusty texture. The mottling and depth is achieved using chalk powder and the methods described.