Easy Lava Effects

I’m currently working on the Fourthcore Team Deathmatch terrains for Gencon. Every single one of these that I’ve made has posed some interesting terrain connundrums. New hills for me to climb, if you will. That’s a good thing, by the way. It’s made me stretch and figure out new stuff. I’ve learned a lot of new techniques and come up with unique ways of doing things. In short, it’s made me better.

The current project required me to tackle lava. In the end, I was surprised at how quick and easy it was, and thought I’d share the process here. Oh, and don’t worry, next week you’ll be getting the full pictures of the finished terrain – consider this a teaser.

This technique works well for things other than a game board with a river of lava; keep reading to the end.

To make lava, you will need:

  • Foamcore – depending upon the size of your board, you will need one or two pieces – in other words, you’ll need two layers.
  • An exacto knife or utility blade
  • Glue – Elmer’s or Tacky glue works fine.
  • Acrylic Caulk (and you’ll need a caulk gun as well)
  • Acrylic paints – small bottle of yellow, burnt orange, and red. Bigger bottles of black and white
  • Paint brush

First, you’ll need to cut two pieces of foam core to whatever size you want your board to be. One piece of foam core will stay intact, and act as the base. The other piece, you’ll cut the “lava flow” out of.

My board is an exact replica of something, so I needed to do an extra step at the start. I gridded off the top board in pencil, and then marked the squares I needed to cut out. This step is completely optional, but will allow you some control over exactly which squares become lava.

When I was done cutting out the lava flow, I put the foam core back together (like a puzzle) because I had an island in the middle of the flow that needed to stay put. Then, I glued the top piece to the base piece, being careful to NOT get any glue on the “lava flow” piece – I needed to be able to lift that piece off when the glue was done drying. I also laid some books on the foam core, so that the glue didn’t warp the boards while it was drying.

The glue dried overnight, and on to the paint! A very basic stone scheme is 3 parts black, and 1 part white paint for a base coat, and then a broad drybrush with 1 part black, 2 parts white. Flat surfaces are fairly difficult to drybrush well, so try and create a little texture with your brushstrokes on the base coat. Also, make sure you get the edges of the lava bed with the base color. (I have premixed color matched latex house paint that I use, but only because I use the stuff in large quantity to paint up Hirst Arts models.)

Once the paint is dry, you’re ready to make some lava. Fill up the lava bed with acrylic caulk. Then, take your finger and swirl around the surface of the caulk. Don’t worry if you get a little “outside the lines,” as you can clean that up when you’re done texturing, and paint it gray later. Swirling accomplishes two things. First, it creates a “flowing” effect, and second, it creates a texture that will take a drybrush well. The acrylic caulk will need to set for about 24 hours. Go take a break!

We’ll paint our lava flow four times. Don’t worry, it won’t take too long. The first layer of paint is yellow, and should cover all the caulk. The second layer of paint is orange, and should be applied as a “wet drybrush.” Oxymoron you say? Think of it this way: the paintbrush should have enough paint on it that most of the yellow is painted over. Only the deepest parts should still be yellow when you’re done. The third layer is a true drybrush in red, and the final layer is a light drybrush in black, with strategic application of wetter paint in certain locations. Four layers seems like a lot, but it will create an effect of hot glowing lava beneath, with cooling lava on top, as well as areas that have fully cooled.

The final step is to draw a grid on the board, if you need one. I used a dark gray sharpie, but black would work just fine. I would definitely recommend a fine tip and a t-square ruler.


Still reading? Great! When I was done with this project, I decided to test the caulk as a Water Effects substitute. After all, I was basically using it in the same way that I would normally use Water Effects. I made a pool (full of lava) and some fires as my test subjects.

I found the caulk to be much thicker than water effects. It’s also “stickier.” In other words, it’s a little harder to work with. Emphasis on “a little.” It’s certainly a viable Water Effects substitute if you intend to paint whatever it is you’re making. I might also comment that caulks also come in other varities (including clear). Given the price tag of a tube of caulk (about $2) vs. the price of Water Effects (around $15), it would certainly be worth experimenting with. Just make sure you cap the tube good and tight when you’re done with it, or it’s liable to dry out.

Note: This tutorial is adapted from one I found at Figurepainters.com. The original was fairly involved and complicated, and since I’m not usually a fan of involved and complicated, I only took the bits I needed for my own project.


3 thoughts on “Easy Lava Effects

  1. Ben

    Great stuff! I’ve really, really pondered trying caulk as a water substitute. I don’t know if it’s the dry air here in Arizona but the Woodland Scenics Water Effects dries out and I end up having to pour it like 3-4 times (and even then, it still doesn’t turn out great). Thanks for the top-notch post. It’s much appreciated.


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