Your favorite mountain making technique/material

John,

The technique to construct my mountains may be a little different as my requirement is for the mountain to be heavily forested. I start with a rough shaping of the mountains surface using 1/2" ply arranged in a box type setup to enable the mountain to be worked on in sections. Next I fit 3/4" green insulation foam (Lowes about $10 for 4X8 sheet) into the boxes forming a rough suface shape of the mountain. I use panel & foam adhesive to secure the foam. Additional pieces shaped with a sharp knife are used to modify elevations if needed. The foam serves as underlayment for the attachment of trees. I then use plaster rolls to coat all foam surfaces. I then brush on white hydrocal to strenghten the structure. Hydrocal rocks made from various molds are then attached with sculptamold where desired. Sculptamold is then used to "meld" the rocks into the mountain surface for a more natural look.The rocks are then colored using multiple spray washes. The surface is then coated with structolite (Home Depot $9 for I think 25lb) The structolite is then painted with WS earth color pigment. A coating of Scenic Express dead fall forest debris or dark adirondack blend attached with white glue mix and sealed with matte medium serves as the floor for the application of trees.

After the plywood shape is decided on, 1 day for foam, 1 day for plaster work, 1 day for rock attachment, 1 day for rock washing, 1 day for structolite, 1 day for earth coloring, 1 day for ground cover. The day intervals are mainly for drying times.

Rich

Here is an interesting method although not real practical for the average modeler.

http://www.youtube.com/watch?v=qV4f5-pg63o

Here is a piece he did for me.

Here are a couple of pieces I did myself using the same foam product.

Made a lake and spillway with the same product.

I use blue foam board, so I can take it outside in sections. Once I carve, shape, paint base color, and initial texture I move it back to the benchwork. Then when all the sections are in place I put on more texture,trees, and stuff to hide the seams. A standard section is 8' long. If I move everything comes apart in sections. I reuse all the scenery as the railroad changes.

Different areas call for different methods.

The left side is pink foam and plain white foam. The right side of the hill was cardboard strips stapled and/or hot glued together with plaster cloth as the base, some casting plaster for fill, and strctolite for the surface coat.  

Across the front is 2 part foam rocks using rock molds from Bragdon. We had less than an inch of space to work with the foam rocks are very thin and flexible before they harden. The entire area was primed with artist Gesso to help take the color wash consistently.  

The middle section is plaster rocks that were made with the same Bragdon rock molds.

Sculptamold was used to fill in the gaps between rock pieces, and then the entire ara was "painted" with artist Gesso (primer) so it all takes the color washes consistently.

We have more hills to do which we will use cardboard strips to build the base, or crumpled paper depending on the area, with plaster cloth over that for the hard shell.

I use resin from Bragdon for casting rock. Though there is a learning curve. I tried both plaster and blue foam on previous layouts and found it messier than I like. 

Mine is paper mache. I would like to do a few more things to it, but I like it so far:

Plaster-dipped paper towels on screen wire used to be my standard method. These days I'm using Sculptamold (with a little white glue added) on foam and still use plaster for any rock castings...