I am using extruded foam board to build a multi-lawyered section on an HO layout. I have cut a gap between two sections for a train to pass trhough at the base level and want to bridge that gap for a city scene above the gap. By using a thin material I can have an appropriate clearance. I need advice on what material to use to "cover" the gap. It will be approximately 2.5 inches wide and I have some concern that cardboard material, which would be thin, might bow in the gap. Any suggestions? I should mention that in addition to ground cover and paint covering the material that at certain points track and roadbed would also be on top of the material. Thanks in advance. WPE
There are varying thickness's of 'Evergreen' brand styrene you can use if there is only a small gap - ie creek with no need for a bridge pylon. You can always re-enforce this type of construction with styrene strips also.
Perhaps a foam-core/styrene "sandwich"??.........thin styrene, but thick enough to add rigidity to the foam-core.
A number of years back, I bought a 4x8 sheet of plastic-coated masonite at the hardware store. It's used for lining bathroom showers. I have subways on my layout, and the trains are just below the conventional "top" layout. I cut sections of the masonite, which is about 3/16 inch thick, to fit over the subway tracks, and notch the edges of the pink foam so that the masonite ends up level with the rest of the surface layout. I cut rectangles out of the masonite, which is coated with white plastic on one side, and use them for control panels. The other side is dark brown, and I put that to the outside when I cut sections for fascia. I think I paid $8 for the whole sheet.
I use 2-3 layers of Woodland Scenics Plaster Gauze to cover gaps that large. The cardboard will hold the first layer in place and level until it starts to set in 15-20 minutes. Then just add as many more layers as you may need to support whatever weight the scenery and track will add.
Can you take a picture of the gap? I have a hard time visualizing it. I'm sure lots of lightbulbs will light up once people see what it looks like!
I will take a picture once I have the gap set up. Imagine the extruded foam with a curved cut or gap. Once there is a gap one piece of foam will be on each side of the cut or gap. The gap will be wide enough for a single curve of Code 83 HO track and roadbed to go through. That is the base level that sits on the framework. The foam is 2 inches thick-not enough for clearance. The foam is elevated off of the base to create a greater clearance of 4 inches. The top of the foam will have a level yard and town that will be set up on both sides of the gap. So I need to "bridge the gap" with a material that is very thin (to protect my clearance) but strong. I will ultimately "hide" the gap so that it is invisible beneath whatever material I use, painted, ground cover, track and roadbed. To me this is a simple way to let a train pass beneath the yard and town without being observed which would not be an accurate depiction of the town or yard. Hope that makes sense.
MisterBeasley's advice is good MisterBeasley's suggestion of the coated masonite is a good one. For short spans as you've described, it will be effective, easily workable and inexpensive. For the layout builder, that material has a thousand uses. I recommend adhering it the styrofoam using inexpensive latex painter's caulk.
