The other day I was throwing out a cardboard box that an item of flatpack furniture had come in. For protection, the manufacturer had put some long thin plastic bags into the box then squirted expanding foam into them. The foam expanded and wrapped itself around the edges of the items forming a custom-fit protection. When my granddaughter, my scenery expert, saw the foam, she declared that it would be perfect for building out the landforms on the mountain edge we were working on. And she was right! The hardest part was getting the plastic wrap out of the crevices in the foam. That stuff cuts nicely with a fine toothed saw (old hacksaw blade), makes very little mess, less than styrofoam insulation, and attaches nicely with latex caulk. And it’s very light weight. A layer of plaster cloth over it, some drywall compound over that, and the mountainside is taking shape nicely.
Sounds interesting. How about some pics. My first question is, “why is this not a more difficult way to get a basic mountain shape?” I will follow this thread because I am always looking for new ways to make scenery.
Sorry, too late for pix. The foam is covered with plaster cloth and drywall compound now. I never think about taking pictures of the work in progress on my layout. Then afterwards I think, “darn, I missed some good photo ops.” Unfortunately the basic landforms are in place for the mountainside now, so I won’t be using it again until much farther down the road, that is if I ever decide to make more high places. However, knowing my granddaughter, she just might find a use for some of the leftover pieces. She thinks it’s neat stuff to work with. Now, if I can only remember to get my camera!
I wonder if it would be possible to spritz the liquid foam onto some scenic landform, then do the Gutzon Borglum (or Korszak Ziolkowski) thing with it after it hardens.
Has anyone ever done that, or anything similar? It will be (longer than I care to admit) before I’ll be able to try.
Chuck (building the netherworld under Central Japan in September, 1964)
Spray-on foam is my favourite way to make landforms, but it’s difficult to control as it piles up, and it looks like a very long sausage extruded onto itself. It’s best to be patient and let it set before adding more height, but patience isn’t my strong suit. As stated, it carves wonderfully well and accepts paints and all the glues we normally use.
The pic shows the spongey texture when cut. I use DAS clay or plaster to cover it.
Nice job, Mike. Looks very realistic, especially the way you layered the colours, brown earth, tan clay.
i’m somewhat concerned with using expanding foam intended for packing . you’d have to do some research into what chemicals are released over time with this product since it isn’t intended for household use , also the flamability of this product may or may not be a problem . there are spray foams you can buy in a can at home depot etc. for insulation and filling holes that hopefully have been tested to be safe .
I tried using expanding foam for rock molds and the results were not good. Air bubbles get trapped between the foam and the molds and the rocks came out looking like Swiss cheese. I can see using it to build landforms. It would work much like foam board to build up the land forms and would be much more flexible. It would probably not waste as much either. Can it be cut with a hotwire or shaped easily with a rasp?
It can be sanded and filed, and cut with a saw or a craft knife. On the cans I’ve used there are warnings about subjecting it to heat, so I wouldn’t be using hot wire on it. No doubt it would release toxic fumes if burnt - but so do I [:)] I recall reading that white styrofoam would do the same.
Mike
Yep. You can cut it to shape and it holds it’s shape better then crumpled up newspaper when you cover it with plaster. I got big blocks of that stuff from where I worked. I ground it up in a food processor and colored it with craft paint. It makes excellent ground foam and tree leaves. You can do colors that are hard to find. Once you cover it with paint or plaster, I doubt if you have to worry about any toxic stuff. I made enough for a 8’x15’ layout for about $20.