Use Gator for structural and insulation foams for contours
Hello there,
I am an industrial engineer and have been experimenting with foams for many years to use as either plywood or plaster replacement. I don't use those materials any longer to construct my layouts. I think it would help our hobby immensely to migrate away from the old fashioned heavy wood construction which has been around for many decades. Similar to the construction used in a house, old school methods use plywood, dimensional lumber and plaster.
Unless you plan to stand on your model railroad, the heft and weight of the construction is completely unnecessary and just makes the model too heavy, inflexible and difficult to move or modify--- Its really way "overbuilt".
Why not have a more appropriately engineered, lightweight model structure using available contemporary materials?
To be practical, portable show model railroads have sometimes used these more modern construction methods- for instance the N Scale Clinchfield, which utilized an aluminum frame. Today many of us live in apartments, and at some point will have to move our model railroad.
In 2017, there is no reason model railroaders shouldn't be using faced, flat foam boards, cast and carved foams, along with steel and aluminum metal reinforcement to create benchwork for their model landscapes. I am talking about hard Gatorboard here not common "foamcore" which is too soft and weak.
The only downside is the slightly higher costs, and perhaps learning a few new skills. I would argue that the benchwork deserves more attention than most people pay to it, and why not support your beautiful models with a quality foundation?
For model railroad subroadbed and benchwork, There are three roles to fill:
1) Stiff and strong structural panels for benchwork construction
2) Soft, easy to contour "filler" foam to create scenery shapes
3) Smooth dense "facing" foam which will hold very fine details- rocks, retaining walls, roads, even bridges, this includes Bragdon enterprises resin rocks - Geodesic foam
Used together in glued layers, these make for a very rigid, strong yet lightweight structure for today's model railroads.
There are many types of foam beyond what most modelers are already familiar with - foamcore and pink or blue insulation foam.
There are literally dozens of high quality foam boards both faced and unfaced. For instance, Fine textured closed cell foam - often sold as an insulator has also become a staple of artists and designers and model railroaders.
It comes in a variety of textures, hardness and prices. Professional industrial foam can be expensive. And even the hobby Balsa Foam is not cheap.
Foam is rated in pounds which is the crush resistance - higher the number the denser and harder to carve. The expensive foam is finer grained for better detail, and doesnt "shed" as much.
For the past 15 years I have been building layout benchwork with rigid faced foam materials. I "discovered" gatorboard when doing a backdrop and observed its high strength properties first hand. For scenery, I have also worked with German made "Modur" rigid foam and some balsa foam PLUS the casting kit sold by Bragdon Enterprises for thin cast resin panels and rock faces. Filler and contouring material can be simple white foam or the popular pink or blue insulation foam which is in wide use. My current model railroad contains no wood or plaster.
FYI Here is a list of some of todays available foam materials: The average modeler is not familiar with some of these versions. For modeling, my favorite is Gatorfoam or gatorboard. (Same thing)
Polystyrene (in softer, 5psi pound versions) - "Styrofoam" Dow Chemical - is the soft disposable foam used in cups and packing material and is too soft for permanent use.
XPS - Rigid Foam Insulation - , Extruded polystyrene sheet - Dow Chemical is Blue, Owens Corning is pink and includes different densities Foamular 400, 600, and 1000 is Owens Corning's 40, 60, and 100psi foam. It is the same —measurably identical— as Dow's Highload 40, 60, and 100 There are also others Pactiv Greengard (light green) and RMax Thermalsheet in light gray.
Gatorboard - Laminated Polystyrene & Luxcell - Gatorfoam® foam board is an extruded polystyrene foam board bonded between two layers of Luxcell wood-fiber veneer. It is very stiff, rigid and heavy duty, yet a versatile foam board which is perfect for many model railroad structural uses. It comes in thicknesses from 3/16 to 2 inches thick! Most modelers have never seen Gatorfoam. It is used in sign shops, and is only sold retail at a few art suppliers.
Ultraboard - Laminated Polystyrene & Styrene Face - UltraBoard is a premium sign material which has styrene facing instead of Luxcell, however, due to the flexible nature of styrene, it is not as rigid as gatorboard.
Foamcore - the common "Paper-faced Foam Board" you see everywhere. It consists of three layers – an inner layer of polystyrene foam clad with front and back outer facing of either a white claycoated paper or brown kraft paper. It is Vulnerable to moisture - Warps and very substandard inexpensive foam board compared to other boards. Craft people find ways to use it and like it, but doesn't have permanency of other products. Ideal uses - temporary structures, mockups, templates etc
Structural / Core Foam - all sorts of high end honeycomb, carbon fiber aerospace etc - the aerospace industry has a whole catalog of industrial grade, very expensive foam panels for a variety of applications for aircraft and spacecraft.
RF & Microwave Shielding Foams - black, coarse foam used for various rf shielding uses. Not generally suitable for modeling applications.
Falcon Board - 100% recycled printable paper product with a paper honeycomb core and smooth white exterior - rigid and cheap - good candidate for backdrop support 1/2" and 3/16" thicknesses.
Rigid Urethane Sign Foam - 3D signs graphics and displays - similar to below - designed for CNC machining - aka "High Density Urethane" - The tighter cell structure of the new Precision Board Plus High Density Urethane foam board has produced improved machining characteristics, Higher machine feed rates are easily achieved compared to wood, epoxy and alloy substrates.
Sintra - PVC faced, hard foam core - which is heatable and bendable Sintra is a lightweight rigid board of moderately expanded closed-cell PVC, manufactured by 3A Composites USA Inc. available up to 19mm (.750) Has some interesting applications in model building.
Phenolic foam is a lightweight, high performance, thermal insulating foam that possesses excellent mechanical strengths.
Polyethylene Foam (PE) is a strong resilient closed cell foam. Used for shock absorbing, vibration dampening, loose fill, and cushioning.
Reinforced Polyurethane Foam - 3M Reinforced Polyurethane Foam, a lightweight and rot-resistant alternative to plywood for use in structural and semi-structural applications. These polyurethane foam boards with fiberglass reinforcement provide high strength in applications including marine, transportation and general construction, with a weight savings ranging from 30 to 60 percent versus plywood. If you need something really tough, this is the way to go.
PolyISO FOAM CORE - Polyisocyanurate - Trymer® - Polyisocyanurate foam is a rigid foam that has the highest insulating values of any conventional foam insulation commercially available today and often has a glued surface facing for convenient application.
I use strips of aluminum to reinforce longer pieces, and my modules/sections are super strong, resistant to warping or moisture and super light weight - less than 10 lbs! Great for train shows or when you have to move.
There are a handful of modelers who use these materials, but I think its only a matter of time before they get discovered by a wider group of progressive, forward thinking model builders.
Brian Williams, N scaler, modeling the SP in the transition era.
