N Scale -Thinking of 4-5 inch foamcore as ground level on 4X6 table. Objective is the ability to dig gorges, canyons, rivers. Is this practical? Is there a better way? Thanks. Sid
Foamcore is probably not the best choice. Extruded foam is more often used if you want to stack it that deep – as discussed in your last thread on the same topic (with the same title):
http://cs.trains.com/TRCCS/forums/t/207642.aspx
People often use the terms interchangeably, but they are not the same thing.
Foam core is up to about a 1/2" thick piece of foam with paper bonded to each side. You’d need a lot for 4-5 inches
Extruded foam is the pink or blue stuff a lot of folks use in 2" thick boards:
If you really need that much depth, there are much better ways to achieve it than buying expensive material, stacking it, carving it, and then throwing most of it away as scrap.
There are many ways to build scenery – different techniques work better for different needs. A solid monolithic table with blocks of material stacked on top of it may not be the best way to build your model railroad. But until we see you plan, folks can’t help you much with specifics.
Good luck.
Example: Hidden trackage inside a tunnel will need access.
I’d use a base of 2" extruded foam. Where you want something deeper, cut out the base and attach additional pieces underneth to reach desired depth. Only needs to be a 2" or 3" wide pieces underneath. Latex caulk should hold the pieces together with no problems.
Good luck,
Richard
If you are modeling prairie country, where all the drainages cut down from a flat level, the best way is to use a single layer, and glue additional pieces to the underside only where the scenic elements require it. You can use some of those, “Cut out of the top,” pieces to extend the contours downward.
If your terrain resembles mine (or the depths of the Grand Canyon,) with contours climbing up as well as down, a solid tabletop is NOT the best way to fly. My sub-ballast roadbed (which consists of a bunch of grades connected by flat station areas, no two on the same level) is cookie-cut plywood, no wider than the right of way fences and frequently (on fills) narrower. My landforms, like the roadbed, get support from risers screwed to the joists and girders of the `C acts like L’ girder framework below. If I stacked foam to form the landforms on my DOWN peninsula the stack would be over two FEET thick - and I wouldn’t have any place for the other four levels of non-visible track in the netherworld under the mountain.
To summarize: If your terrain is basically flat, use ONE layer of foam as a base. If your contours go vertical, consider other methods of putting a skin on the mountain. There is no universal technique.
Chuck (Modeling Central Japan in September, 1964)