I have started gathering materials to start on building a 3-foot X 6-foot N scale layout, based on a track plan I saw in an Atlas Model co. trackplan book.
The article (and plan) suggest a plywood "cookie-cutter" benchwork approach with plywood for the base of the scenery. However, insted of using plywood, as suggested in the article, I would like to use some foam insulation board that I already have on hand.
Would foam insulation board be flexible enough to lend itself to the "cookie-cutter" benchwork design as plywood is, or would it be a better idea to go ahead and buy the plywood, and lay the foam on top of that?
Generally the foam used in benchwork will be too rigid to transition smoothly from the horizontal to much of a grade. What depth of foam do you have and what's the percentage grade you're looking at?
A couple of alternatives:- use your existing foam as the solid base of your layout and add more of the foam on top, carving and sanding the grades into those top layers or, use the Woodland Scenics incline and riser sets. Although they're not that cheap, they do guaratee smooth grades from the flat and they are really easy to use.
Ian
ianalsop Generally the foam used in benchwork will be too rigid to transition smoothly from the horizontal to much of a grade. What depth of foam do you have and what's the percentage grade you're looking at? Ian
Thank you for your input Ian.
I have a 4X8 sheet of 3/4" thick foam insulation, which you are right about being too rigid. I still have no clue what grades I'll be looking at, but I know that the tracks have to be tall enough to clear a main line on the lower level.
I don't know 100% yet what my approach will be for the benchwork, but I'll probably follow your suggestion, and build the scenery up with layers of foam.
3/4" thick by 4' x 8'? Even at 3x6 thats going to be very flimsey without some form of bracing. I used 2 x 8 blue foam that was 2" thick and I thought that was iffy. Is this going to be mounted onto sawhorses or legs of some sort? I would suggest using 1x3's or 1x4's to "box" the foam and use 4 or 5 1x3 or 1x4 stringers flat across the bottom of the foam to reinforce it and give the legs something to rest on. Also foam needs to be glued down, screws will pull out with mimumum of effort, so while you can screw the lumber together the foam will need something like Liquid Nails Home Projects or some other adhesive (I used caulk) to secure the foam to the 1x reinforcing lumber. Also adding pull handles on each side of the layout helps greatly if it needs to be moved around alot.
Have fun with your trains
This might give you some ideas.
Works OK for me.
Use 1/2" or other foam for the bracing (risers) too.
Not at all flimsy. More like a rock...a light weight rock.
Jim Murray The San Juan Southern RR
jwmurrayjr Works OK for me. Use 1/2" or other foam for the bracing (risers) too. Not at all flimsy. More like a rock...a light weight rock.
Yes, When its adhered down to a good base or benchwork, I notice thats some pretty substantial benchwork under all that foam
The way the OP stated it it sounded like he wanted to use it loose, at 36" x72" x 3/4" thick without any sort of wood sub-support and everything on top of it. That would be flimsy in my experience as the foam would be vunerable to flexing or breaking off corners.
I have built several portable layouts, using a 1x3 frame around the foam gives it support and rigidity and protects the foam from impacts, especially if it gets moved about . Thats all I was trying to point out.
This is on a plywood "table" of course (bolt together modules). but everything else is foam.
If I were doing it again I would use only the blue foam.
vsmith The way the OP stated it it sounded like he wanted to use it loose, at 36" x72" x 3/4" thick without any sort of wood sub-support and everything on top of it. That would be flimsy in my experience as the foam would be vunerable to flexing or breaking off corners.
Accually, That isn't how I was planning to use the foam, although I will keep that in mind.
My idea was to build benchwork with 1X4s, with risers placed onto the benchwork (as with traditional layout building techniques) and use 3/4" thick foam in place of the 1/2" thick plywood.
Sorry for any confusion.
I built my layout using 3/4" plywood on a 1" x 4" frame with 1"x4" on 16" centers. I then glued 2" x 24" pink foam slabs over the plywood.
I then used Woodland Senic risers and additional slabs of 1" x 24" pink foam for additional elevation.
If I had it to do over again I would skip the plywood entirely and just glue the foam onto the wood frame.
Mind you I do not have to climb on any part of the layout. All areas can be reached without having to climb onto the layout.
I think that you may find that the "traditional" wood risers are not adequate for the 3/4" foam and you may need to use some foam to "box" your 3/4" roadbed.
See website for examples.
one way to add substantial amount of strength of foam is too sandwich it between luan.
model in O. the Western NY and Ontario Railroad
The 1/2" foam superstructure gets its strength from the "box girder" effect of the construction. The photo below shows a good example of this "box" effect.
The cookie cutter sub-roadbed is supported by vertical "walls" of the 1/2" foam which are glued to the foam base sheet and, of course, to the sub-roadbed forming a very strong box-like structure.
Even though the riser wall sections may be cut in short lengths to make cutting and fitting easier the sub-roadbed and base sheets are mostly monolithic. The resulting structure has many of the qualities of box, "T", "L" and "I" beam girders making the overall "superstructure" very rigid and strong.
This is all held together with white glue which is strong and easy to use and clean up.
Once the foam "substructure" is covered with hardshell and scenery it is even stronger.
Have fun,
I am following this thread and have a question. Blue foam, pink foam, what is the difference and what is best to make smooth cuts? Sorry if this sounds stupid but I have never worked with these materials.
Hi, Iowaseabee,
The color of foam doesn't mean anything; it only has to do with the company that makes it. Owens-Corning, for instance, uses pink because that's their trademark (they advertise with the Pink Panther). It's functionally the same as blue or tan foam of the same thickness.
The only thing to be careful about is making sure you get extruded foam, which is solid and even throughout. Avoid the white expanded-bead foam board (which is the kind used in Styrofoam coolers). It is less dense than extruded foam and tends to crumble when sanded, cut, and shaped.
--Steven Otte, Model Railroader senior associate editorsotte@kalmbach.com
The concept of sandwiching luan (presumably 1/4 inch or 1/8) between two sheets of foam is an interesting idea. if you think about it, the "gator board" out there, sold by outfits like Garston Sign et al is pretty stable stuff.. This is a timely idea and would, I think, have its place in the hobby, specifically in layout or better yet, diorama usage.
Steven Otte The only thing to be careful about is making sure you get extruded foam, which is solid and even throughout. Avoid the white expanded-bead foam board (which is the kind used in Styrofoam coolers). It is less dense than extruded foam and tends to crumble when sanded, cut, and shaped.
Styrofoam is the trade name for the extruded blue foam made by Dow. It is not the foam used in the coolers mentioned by Steve, the ubiquitous coffee cups, egg cartons, etc. I realize that stuff is commonly called Styrofoam, but it is not.
Dante
I use a lot of foam in my building, My benchwork is 1x4 framing with cross members every 16" and then I do use 1/4 plywood over that and then use different thickness of foam to build up from there. If I want to cut in a river I have the 1/4 plywood as a good solid base. I've also found the new multi tools on the market carve the foam really well. I have a hot wire cutter and it is ok but I find it sometimes hard to carve on mountains but the multi tool has blades 1/2 to 1 1/2 wide and works great, give it a try. The only down fall to the foam, I like to use scenic fiber to cover it instead of plaster or hydrocal but the fiber slides around so you have to cover it with the mesh tape for drywall work. The scenic fiber works really well and it is extremely light and it has great working time, can be colored and you dont have any waste as you can re wet it and start over instead of breaking it out of the bowl and throwing away what dries out before you get it spread.
Dugan