Big Thunder Creek: Part III ~ Waterfalls, Rapids and Pools

Click here for part I
Click here for part II

An eagle soars high above Big Thunder Creek as the TMMC crews go about their daily work. The cold, clear water issues from a hidden spring below Baxter's Butte, creating a green oasis of life in the midst of the red rock desert. Backdrop and smoke effects added with Photoshop, all else as modeled.

Water has arrived in the desert! As the spooky Never Mine takes shape on the slopes above, a flash flood of clear epoxy resin has transformed Big Thunder Creek from a dry and dusty wash into a gurgling, splashing oasis of life. This past week was spent creating the water effect for Big Thunder Creek and detailing the surrounding scenery. Follow along with the photos and captions as I describe my process for creating believable waterfalls, rapids and pools with acrylic sheet, clear resin, paint and silicone caulk.

The Creek Bed

Before modeling the water itself, the creek bed needed to be detailed. A layer of sand and small stones collected from real creeks in Sedona, AZ and Silverton, CO was laid down and glued in place with a generous amount of matte medium diluted 1:1 with water. 

Once the glue for the stones had set, cattails, tall grasses and other greenery were added along the banks. I wanted this area to appear more lush and green than the rest of the layout. Most of the plant material came from Woodland Scenics and Scenic Express. Note that the foreground trestle deck was still removable at this time to allow for modeling the creek.

The Waterfalls

There are several different ways to model waterfalls. I chose to use a technique learned from Sam Towler's fabulous Nature's Wonderland layout. Basically, 1mm (.04") thick clear acrylic sheet is cut to size, and then textured with a hot soldering iron. I built on Sam's original technique by also using the soldering iron to fuse strips of acrylic together and to shape and sculpt the falls into the more complex forms needed. More acrylic was fused in select places to show variations in the flow of water, and more was added at the bottom of the falls to simulate foam and splashing water. Warning! If you try this technique, use breathing protection and work in a well ventilated area. Also, don't burn yourself with melted plastic or the hot tip of the soldering iron. And always look both ways before crossing the street.

My creek needed three waterfalls and each was sculpted to fit its particular spot. Here, the edges, lip and foamy bottoms of the two lower falls are being highlighted with white acrylic paint. Highlighting is done on the top surface. This is later covered with clear resin or gloss medium to bring back the shine.

Dap 3.0 Crystal Clear Silicone Caulk and Sealant was used to glue each waterfall in place and to act as a dam to hold back the Envirotex resin in each pool when it was poured.

Here, all three acrylic waterfalls are in place and it's just about time to mix up some Envirotex. Note that the walls of the canyon have been darkened at their base with some dark browns and a touch of moss green to simulate rock dampened by mist and splashing water.

The Pools

For the water in my creek I used Envirotex Lite, a two part clear epoxy resin.  It's a really good idea to wear gloves while you do this because you don't want this stuff on your skin. 

I mixed up small batches in 3 oz dixie cups, taking my time and following the directions. Measuring and marking 1/2" from the bottom of each cup (one for resin, one for hardener)  helps to accurately measure the required 1:1 portions of each part.

The resin was mixed 1:1 with the hardener, stirring and scarping with wooden stir sticks for about 3 minutes. A drop of moss green acrylic paint was added to the first pour for depth and color. This project was done in several successive pours and used almost an entire 8 oz kit of Envirotex Lite.

Here's a shot after the first three pours. Envirotex Lite is self leveling and will slowly flow down to settle in the lowest spots (make sure your creek bed doesn't leak!). I started at the topmost pool above the highest falls and worked my way down to the bottom, allowing the resin to spill right over the falls as it went down. A masking tape dam across the fascia kept the resin from oozing right off the front edge of the layout. This was allowed to cure for about 48 hours.

Rapids and Fast Water

Envirotex is great for modeling water but it cures completely flat. For rushing water and rapids, I used clear silicone caulk applied in strips and dabs, directly on top of the cured resin.

A flat toothpick was used to spread, feather and form the caulk into waves riffles and rapids.

Fast water below the big falls.

More rough water caused by stones below the surface. The caulk was applied in any logical place where the water would be fast or disturbed by rocks or other obstacles in the creekbed. It helps to look at lots of pictures of creeks and rivers!

Behind the lefthand trestle pier is a calm backwater. I gave this a mossy, overgrown look by dabbing dirty green acrylics onto the surface with a small brush.

Once the caulk had set overnight, highlights were dry-brushed on using white acrylic paint and a light touch.  This was followed by a thin, clear topcoat of resin poured over the entire creek and brushed across the tops of the rapids.

The final step was to further break up the flat surface of the water by swirling and stippling acrylic gloss medium in the faster moving sections of the creek. 

When dry, these surface ripples reflect and refract the light, adding to the sense of realism.

Up Next

The creek scene is starting to come together. In the final part of this series, I'll describe all of the little details that help bring it to life.

With the completion of the water effects, Big Thunder Creek is just about done. But the creek itself is just one element in a larger scene where many details large and small will help bring it all together. As always, thanks for checking in and following along. Comments and questions are welcome below. Happy trails amigos and adios for now!

It's been a busy day at Big Thunder Creek. I wonder if the fish are biting...

Click here for part IV