mountain construction

I used a combination of cardboard strips, wadded up newspaper, plaster wrap and hot glue to build my mountain/tunnel.

I use cardboard strips, heavy duty paper towels dipped in structolite ( home depot $12 for a 50 pound bag). Then I sometimes add sculpamold and paste in plaster rocks.

I use cardboard strips covered with red rosin paper on my current layout.  I used newspaper and brown paper bags on a previous layout.

Covered with plaster impregnated cloth and top coated with Structolite.  Nice, light hardshell scenery base

I built my mountain 40 years ago.

Sears Textured Paint, a powder that was mixed with water to make a paste was used to cover the aluminum screen wire.  Textured paint was used by painters to add swirls to ceilings to hide the tape seams and may not be available now but something similar should be available.  It has proven to be a great mountain material and did not crack and is much lighter than plaster of Paris and is more durable than paper mache and not susceptible to bug attack.  The textured paint was used to soak paper towels that were laid on the wire screen to form the surface.  Several layers and coats were used.

The mountain is light weight and been moved to 5 different houses.  It has held up well.

Charlie

I used the "Glue Hardshell" technique pioneered by Howard Zane.  It involves card strips attached to the layout w/ hot glue, and red (or other) cheap, absorbent paper.  The red paper such as movers use to protect carpet is supposed to be the best- but I used brown paper.  A single roll, and I still have a fair amount left.

After making the framework using cardboard strips, and being sure to connect the strips to one another in the process, you cut reasonable lengths of paper - maybe 2 ft. X 4 ft., wad it then re-open it.  The more you stretch it back open the smoother the terrain will be.  In sections where you want a "meadow"- don't wad it at all.  

Then, using carpenters glue,  bought by the gallon (I used Elmers ) and per Howard at full strength, you use an old knarly paintbrush to coat the paper with the glue.  By the time you coat the mountain  fully, you should be ready for a second coat.  Allow the shell to dry overnight, then paint using earth brown, or other dark color cheap latex paint.

Great topic!  Probably a Really Dumb Question (because I've never built a layout with variable terrain.)  When you build tunnels and mountains using these techniques, what do you place over or on the track to ensure that there's a hollow passage with a cross-section large enough for the train to pass through when it's all finished?

To give an example: back in the old days, you were supposed to drape screen wire over wooden frames, and then spread plaster over the screen wire.  The wooden forms ensured sufficient clearance for the train.  Once the plaster dried you could enlarge the outside of the mountain to any desired shape.

Today I understand that using screen wire is a big no-no because of "ground planes," command control signal doesn't penetrate it, etc.

I probably need to buy some scenery how-to DVD's, if anyone has recommendations.  I have zero experience with this, and I'm just really struggling to visualize the sequence of events.

Wood, nails, screws, plaster, plaster of Paris.  A very good plaster cloth product.  and rock molds.  Click on the underlined phrases to link. 

I simply made foamboard rectangular "boxes" around the tunnel entry itself, and then used crinkled up aluminum foil, painted flat black, to create the appearance of a "blasted" tunnel wall and ceiling.  The foamboard boxes are accessible through the back of the layout, with little handles on them- so I can remove them for maintenance.

I left the middle section of the tunnels open and accessible from the back of the layout.