Help w/ extruded foam

[Ironhead]

Greetings all. I am working on layout with rock formations carved out of pink extruded foam, and I am interested in how some of you may have applied paint to this. I'm still a little confused on the washes process.

My plan was to prime it with water based gray primer a couple of times, and then apply some flat black into the crevasses to create the dark shadow effect. The next step is what makes me unsure.

I've read about washes without any specific detail on what type of paints to use, how to mix them down, or the best way to apply them to foam. I have purchased some acrylics in a variety of colors as well. The only thing I'm really sure about is that the colors need to be applied in order of darkest to lightest. The formations themselves should model dark granite.

Anyone here had success with painting this stuff?

 

[MasonJar]

Welcome to The Gauge...!

I would apply the dark paint as a wash to make sure it gets into all the crevices... If it is water based paint, you can thin it with water and a bit of isopropyl alcohol or a few drops of dish detergent (don't shake...!). The last two items are options to break the surface tension of the wash so it does not bead up.

Once that is dry, I would recommend dry-brushing to add colours to the rocks, followed by another wash to blend it all together.

Good luck with your project.

Andrew

 

[bigsteel]

i usually put hydro cal or drywall compoud over foam to add even more cracks and make it more rocky lookin,not so smooth then i take latex paint and put over my first layer of rocks,landscaping and ground.then i do the main colors and wash it down and finally drybruh on the tips of the rocks light grey to create higlights.but there are alot of different ways,so just listn to the people here and decide which one you want to use.

 

[Nazgul]

Ironhead...
When I do rock work, I use foam, sculptamold, and even real rocks.
In these pics, the vast majority of "rock" in the close ups is foam.
View attachment 34849

View attachment 34850

View attachment 34851

I use an airbrush and acrylic paint.
I start by spraying everything black. then I spray a light coat of the darker brown (you would use your darker gray). vary the coverage and be careful not to cover over all the black. Last step is to take a natural sponge and cut a small irregular piece. dip it in the light brown/gray and dab it on a piece of newspaper or something and get the excess off so that it leaves only splatter, not smudges. Then dab it on in a random pattern, going heavier where the "rock" is raised or area you want to highlight.
If you can't airbrush...do the first two steps with a brush and the last with the sponge. I think the sponge painting raises the level of believability.
This is ONE way do it...there are many others...hope that helps or at least gives you some ideas.

 

[MasonJar]

Nazgul,

That is some great looking rockwork! I love the large "slab" faces - very typical of Canadian Shield. Many of the rock molds have too fine a texture, or represent sedimentary rocks.

How about a tutorial to go with the waterfall one...?!

Andrew