I decided to make the water panels before finishing the river bank sections. The water panels were cut from .06" thick styrene plastic sheets. I buy it in 4'x8' sheets from industrial suppliers and cut it down to the size that I need, in this case, 2' square, 1'x2', and 1'x6" panels.
I then applied a coarse coat of artist's acrylic paste to the sheets (barely visible in the photo below), brushing it on with a 3 inch brush to give indication of the flow of the water on the finished panels.
Once the paste was dry, I mixed a muddy olive color with artists acrylics and painted a base coat of "water" onto the panels and later drybrushed with a lighter mix of the muddy olive to give some contract to the peaks and valleys created with the paste. Once dry, two coats of artist's gloss medium finished the water. Finished panels are shown below.
The paint dried a little more grey than I had intended, loosing some of its muddy complexion, but I decided to go with it, as I didn't want to repeat the step.
With the water more or less done, I returned to the river bank portion of the project. I don't really use a primer on the foam, but paint on a coat of the artist's acrylic paste. Woodland Scenics offers similar product, though I usually us a thicker version from Liquitex. This helps to protect the foam and soften any unwanted hard edges that remain after the shaping process. A coat of paste is simply painted on with a 2-3 inch wide brush and allowed to dry.
Once the paste is dry, it is time for paint. I start off applying a base coat of colors that helps me to visualize the final colors. The muddy banks in most of the photos that I had (working from about 50 pics from various sources) depicted mostly dry, cracked mud of a light chocolate or "baby-poo" color. Sometimes the color seemed to shift to a more slightly yellow color where dry ground continued away from the immediate river bank area. Curious to me was little indication in the photos of the reddish brown mud colors that I often have read about.
I decided to paint the exposed banks the baby-poo color, and transition to a more yellow (too yellow as compared to the photos) so that the terrain could mate to my older jungle terrain. This would save me the time and space needed to complete a completely different set of jungle terrain for Vietnam.
The first stage was the base coat, mostly yellow, a burnt umber for the banks, and areas of darker baby-poo along the banks.
Once the base coat was mostly dry, I went on to the final colors. This involved applying the baby-poo to the banks, allowing the burnt umber to show through only in the crevices, highlighting the upper portion with a lighter, more faded poo mix, and the lower portion of the bank with a slightly darker, wetter looking mix of poo, which doesn't show up so well in the photo below.
The rest of the terrain was finished using shaded baby-poo on all of the exposed mud areas, and blending it into the yellow that matched my old terrain. With the water panels in place, the terrain finally started to take shape below.
Next step was to add flock to the terrain. I used a mix of Woodland Scenics products, as they was readily available, and easy for me to match if I add more terrain later.
To apply the flock, I brush on a coat of artist's acrylic matte medium, being sure to maintain a thick, moist coat, and sprinkle on a mix of medium green and light green coarse flock. The ratio is about 20 to 1, medium green to light green. Over that, I apply a mix of fine yellow and earth blend, mixed 2 to 1, yellow to earth blend. The yellow blend then has a little coarse medium green added to it in about a 10 to 1 ratio. This is all patted down and allowed to dry. Once dry, the excess (maybe 80-90% of the flock) is brushed off and recovered. Most of the fine yellow mix can be separated from the coarse green mix, and reused for similar terrain. There will be a little green in the yellow and yellow in the green.
A couple of views with my PBRs in the water.
Overall, I'm happy with the way the terrain turned out, though the river is a little less muddy than intended, and the river banks have a little less contrast in the mud than I expected.
Originally, it was my intent to use the foliage, ferns, palms, etc, from m 28mm terrain, but the palms in particular are just a bit too tall (and maybe a little too cartoonish), so it looks like I have a new project; making Vietnam riverine foliage. Most of my tropical ferns, bushes, cycads, and deciduous trees should work fine, but I definitely need palms and will add a few more things to Vietnamize the terrain a little. Guess I do some research on that, while working on my post apocalypse terrain in the coming weeks.