To better facilitate possibly moving someday, I am planning on using a foam base on an HO layout without any plywood underneath. Should I be required to move, I would like to be able to pry these 2’x6’ or 2’x8’ sheets of foam right off of the supporting joists. Without plywood, I don’t think that I can have the terrain drop into the lowest sheet of foam (2") for fear of losing structural integrity of the sheet. So, I think that most any drops in the terrain need to be achieved through additional sheet(s) of foam or placing the track and roadbed on risers. I was planning on using a second sheet of foam one inch thick until I realized that I probably shouldn’t dig into the bottom two inch foam sheet.
I think that my dilemma is this. Do I use:
A) Four (2" + 1" + 1") or more inches of foam with the terrain digging into all but the bottom 2" of foam as required; or
B) Do I use less foam thickness but use a large expensive bundle of Woodlands Scenic risers?
Which is the better alternative?
Is this a false choice? Could I get away with three (2" + 1") inches of foam occasionally digging into the bottom 2" inch sheet? Perhaps, if I need to sink a river all the way into the foam, its base could be provided with benchwork?
I would appreciate any thoughts and advice to get me out of my confused state. [8)]
I would plan on moving your framework along with the foam, by removing the legs and leg bracing. build your frame work in small lightweight sections (2’x4’) and screw them together like your playing dominos. When it is time to move cut thru your scenery and unscrew the domino’s from each other remove the legs and go.
What about using a 1x2 frame with a cheap wall paneling panel. Paneling is usually about 3/16" thick, light – yet would give you the stability you’re looking for under the foam.
Here is an idea that I have considered posting for awhile. Use fire rated T Bar ceiling frame under the foam. Put slots in the outer wood frame and place the T bar up side down in the slot with the finished side up. With the various combinations of T bar lengths, spacing can be as small as 2 ft by 6 inches. It will all snap together in a few minutes, light, reuseable, inexpensive, and resolves your concern about structure.
B) Do I use less foam thickness but use a large expensive bundle of Woodlands
Scenic risers?
Cost of sheet(s) of foam versus W/S risers to move the same height needs to be borne in mind here - At 2% you can go 2" in 8’, and you’ve got your ‘dugouts’ for free
If you are planning to dig a smooth channel into the foam, be aware that this is difficult to accomplish. Hollowing out foam is not something that’s easy to accomplish, because there really aren’t any tools to do this smoothly. I would go with a lightweight benchwork frame and detachable legs, as suggested by roadrat. Then you can use risers to bring up your foam to different elevations.
I built my layout with 30" x 72" open grid sections, using risers and plywood/homasote laminate for roadbed, hardshell on cardboard web scenery. Very conventional.
When it cam time to move, I unbolted the sections, unbolted the legs and set two sections on their sides with the sceniced sides facing each other. I then screwed a 30" x 24 in piece of 1/4 in plywood over each end. I then took the 16" high backdrop masonite and cut it to 6 ft lengths and screwed it to the sides. That created 24"x30"x72" boxed layout sections that survived 3 moves. Very sturdy. Two people can pick one boxed section up or it can be moved on a handtruck quite easily.
If you pry the foam off the framework, how will uy support and protect it during shipping?
If I would move, it would be locally. While most of the contents of my house would be moved by professionals, for the model railroad, I was figuring that I would move it myself making multiple trips carrying each section flat in a mini-van or a rented truck.
By using conventional benchwork and conventional methods with a good packing system you can move them with a commercial mover, stack them any way you want and suffer no damage.
From your post, I presume that you will have some type of framing below the foam and to which the foam will be glued. If it is a perimeter frame and the framing is light weight, like 1x3’s of 1x4’s, you can leave the foam attached when you move it if you make the legs removable.
You don’t say if you have crossmembers in the frame or what spacing the crossmembers are set at if you have them. If you have them and they are 16" to 18" apart, you can safely cut into the 2" foam for scenic effects like rivers and streams. The framing below will give enough support. You can even remove small sections of the foam if you need a deeper riverbed. Just cut another piece of foam larger than your cut-out piece and glue it below the 2" foam to form a new riverbed (or highway, or plateau, whatever you need). Any place you cut into the 2" foam can be braced from below with additional pieces of foam. That will strengthen the foam and keep it from bending or breaking during a move.
The 2" foam is pretty sturdy material, especially when set on framing. Plywood beneath the foam is usually unnecessary.
You can have the best of both if you use 1" foam over 2" foam on a cross-braced perimeter frame. You will be able to cut deeper into the foam for a better scenic effect, add pieces below the 2" foam for additional support, AND you can add MORE foam on top of the 1" foam to raise the level even higher.
In case you haven’t noticed, I LOVE foam construction! It is so easy to work with and forgiving of many mistakes, most of which I have made! It is strong enough for layouts and is very light weight. I don’t think I’d ever go back to the old methods of construction!
I really appreciate all of the feedback. Thank you. [:)]
I am building wall-mounted L-girder benchwork. My rationale is that this will take the least amount of carpentry skills (and work) to give me sturdy benchwork. I am fine with needing to re-build most-to-all of the benchwork following a move. I was hoping, however, that the layout’s top, segmented into 2’x6’ or 2’x8’ sections built upon 2" foam, would facilitate me personally moving it (albeit one or two sections at a time laying them flat in a mini-van or truck).
With the L-girder benchwork, I would use cross members spacing them 16" to 18" apart.
The 2" foam from Dow Corning is extremely sturdy. Even though I placed a plywood sheet under it, I still was able to cookie-cutter the entire layout and was able to raise both foam and plywood pretty easily. If you go with 1" foam, you can probably cookie cutter your layout to add the elevation you want. Fasten wood risers to the frame and glue the cookie-cuttered foam to the top. Make sure the risers have enough of an area for the foam to adhere to. Use liquid nails to glue down the foam, don’t use a glue that will degredate the foam. Have Fun!!! Steve
L-girder benchwork is great. Very easy to construct and is adaptable to many situations. L-girder construction provides the means to support roadbed on risers, leaving all other areas wide open. Using foam makes risers and roadbed unnecessary. The foam takes the place of risers and roadbed and provides the elevations required. In addition, foam fills in the open areas providing a flat surface for scenery applications. Mounting L-girder on the walls often makes legs unnecessary, another advantage that leaves the area under the layout clear.
Mounting foam is a little more difficult than mounting the risers and roadbeds that are more commonly used with L-girder construction. Foam is usually glued in place because nails and screws won’t hold in the foam. L-girders reduce the glueing surface, so a good bond is critical to keeping the foam in place. Beyond that, foam on L-girder construction still offers all the advantages of foam, especially deep cuts for more dramatic scenic effects. L-girder works hand-in-hand with foam for those deep cuts because L-girder allows additional bracing UNDER the layout that adds support to the foam.
Using two layers of foam, a 2" topped with a 1" layer, works well with L-girder construction. Once again, getting a good glue bond between the foam layers and the L-girders is important.
I think you have a winning combination here. Ease of benchwork construction, ease of foam construction, very light weight and one-person portability make this combination nearly ideal for your purposes.
If you haven’t used foam before, you will be pleased and amazed by what you can do with it. You may also experience some difficulties. Foam and plywood are similar because they are both flat and easily cut. That is where the similarities end. Foam is so much more adaptable to your circumstances, but it often requires that you think out-of-the-box to make the most of it’s use. If you run into any of these head-scratching situations, don’t hes
