To use foam or not?

Model Railroader Layouts and layout building
1

After being out of the hobby for nearly 20 yr. I am discovering all sorts of new problems and decisions. I notice that a lot of folks are using extruded foam under their track and roadbed. In my day (before extruded foam) I used cork and mounted it on plywood. My new layout will be built on a combination of L-girder framework and around the wall brackets. Right now my plan is to use 1/2" plywood as the base. I am also considering using 1 1/2" foam on top of it, then cork roadbed uder the trackwork. I’m not sure I understand the reasons for adding the foam under the track. I realize that it muffles the sound but I never really noticed a lot of noise uder the old system. I am more than willing to try new techniques…I would just like to understand all the pros and cons behind them. I fully intend to use foam under the scenery so I am talking mainly about using it under the track and cork roadbed. I am looking forward to as many answers as I can get.

Thanks
Richard

2

I’m in the same boat as you. I’m using foam because you can get away with much lighter benchwork, I’m using 1x3"s , 1/4" ply and an around the walls shelf brackets. The big idea of using foam is it gives you a lightweight but strong benchwork, and you can add to it or carve into it, easily create mountains, valleys, streams, culverts etc. Much lighter than the old Ply and Plaster methods. I’m sure you’ll get many replies on this. Also feel free to search the archives, this questions been covered alot in the past.

Good luck, Dave

3

Unlike homasote foam does not warp from moisture, humidity any of that… You can carve it, sand it, cut it, glue more foam to it and sand that. It takes most any paint you throw at it (DO NOT USE SPRAY PAINT, it will melt the foam and let off a toxic gas).

You can cut the balast grade out of the foam to avoid buying the cork road bed. But I’ve seen both done well. It’s easy to add and remove trees you just stick em’ in the foam.

Give me a foam blade and sand paper and I can make mountain after mountain within an hour. It’s easy to make rock outcroppings cliffs etc. etc, works great for making nicly poured coal for your hoppers. :slight_smile:

As for being quieter, well I dunno know about that, you get a noisy engine and it doesn’t really matter. It definatly is lighter than using wood,homasote and plaster.

The only problems I have run into (thus far) are:

You can’t use an atlas under the table switch machine (easily), so you have to use ground throws or come up with some crafty method to extend the atlas machine pin or use the table top version but then you have to be crafty to hide those (I came up with a rather interesting solution to this). The other option is to explore other types of switch machines that have a long pin to go through 1/2" of plye wood and 1-1/2 " of foam.

Cutting and sanding that stuff makes the biggest mess in the world. Have a shopvac handy. I cut mine with a foam cutting blade in a utility knife. A hot wire works too but it smells bad because it melts it.

Using tiny nails to hold the track to it will not work forever, I tack it down until I’m happy with it, then I glue it using good ole Elmer’s.

Give this thread time I’m sure many others will add to both sides of the list.

Good Luck, and above all, HAVE FUN

– here’s photos of my layout using foam (pink and blue)
http://www.crtraincrew.com/layouts/dan.html

4

ONLY USE WATER-BASED PRODUCTS ON FOAM!! I.E.; acrylic paints (Polly Scale, Badger Model-Flex, Tamayia) and white glue ( Woodland Scenis “Foam-Tack glue”, Aileens Tacky glue-a white glue that’s availible at craft stores-Elmers glue, Elmers wood glue. The solvents in other products will melt the foam; and you’ll only wind up with a mess!
There was a great article in the June issue of Model Railroader telling all about how to use foam.

5

Dickee,

Dano99 and Snowey are both right on target. I’ve got a rather large layout (12x25, three level), and I’m building it using a 2" foam base laminated (glued) to 1/4" Lauan plywood, attached to the walls with U channel metal shelf brackets. For linear layout construction and simple multilevel layouts, you can’t beat foam. It’s surprisingly strong and rigid for it’s weight, absorbs impacts extremely well, and is fantastic for creating any sort of terrain you can think of.

I actually don’t think of the mess carving foam creates to be a problem. Yes, it will get everywhere while you’re working, but a shop vac takes care of the problem in no time. Conversely, using plaster creates a wet mess, which requires a lot more cleanup time. Carving “microterrain” into foam to create a realistic flatish landscape is much easier than using traditional scenery construction techniques.

I see that you’re planning to use L bracket construction and 1/2" plywood for your latest layout. I wouldn’t bother; it’s overkill. 1/4" plywood (Lauan or pine) will be more than enough support, so long as your lateral supports are no more than 16"-24" apart. Many nationally known modelers are using 2" foam as their layout base with no plywood underneath at ALL, and they don’t experience sagging issues or breakage. If you’re planning on using 2" foam (I’d suggest it rather than 1-1/2" foam, which isn’t that much cheaper) and plywood, L girders are completely worthless. The main benefit of L girder construction is that it provides an inexpensive and wood saving way to attach risers to the layout, which support the subroadbed. This won’t be necessary for plywood and foam layout construction, if you do a little planning before construction starts. Where I needed freestanding support for my layout, I just created a simple box frame out of 2x2’s and attached the 1/4" ply and 2" foam to that. I weigh 225, and regularly crawl around on this box frame to get at my upper levels (construction is still

6

I’m building my first N Scale Layout. It is 8’x12’. I used 1/2" plywood covered by at least 2" of foam (4" in some places.) Here’s what I learned.

  • It can take more than 2 weeks for glue to dry when gluing large pieces of foam together. Its much better to wait for the glue to dry before shaping.
  • Both Liquid Nails and Yellow (wood) glue work well to glue down the foam. Yellow glue is cheaper.
  • If you uses latex caulk to hold down your track, keep in mind that small pieces of foam “dust” will stick to it and not come out easily. If this happens - leave the foam dust there until you paint the track. If you use floquil or other non latex based spray paint, the foam dust will melt away. I suggest doing as much carving as possible before putting down track.
  • Don’t bother with a hot wire. A sharp steak knife and Surform will do the job.
  • Use soft sanding blocks for detail work.
  • You can use non-latex spray paints on your layout, just be sure to put down a coat of latex based paint first on the foam. This is especially important when painting track.
  • Don’t get too worried about making perfect cuts and slopes. I used Sculptamold to fix areas I wasn’t too happy with. Its a lot easier to put down Sculptamold than it is to delicately shape foam.
7

Richard,

As another guy who was “away” from the hobby for 20+ years I decided to try foam and have been pleased with the blue or pink Styrofoam.

Follow the link below for a little detail about how the construction is going.

[:)]

8

Don’t, whatever you do, don’t use the white “bead board” styrofoam that’s used for packing! Just try using it once, and you’ll quickly find out why! (DON’T ask me how I found out[:)][:)][:)])

9

Amen! (What he said!!)

10

WOW!!! Guys, thanks for the quick response and info.

To dano99a:

The pics on your web site are great ones for showing the construction details…it looks like you went with 1/2" plywood under the foam. orsonroy suggests that is overkill…that luan plywood is enough. I’m a little afraid of going that thin. If you had it to do over would you go thinner on the plywood. I’m not too concerned about the cost or the weight so much as the strength. I may have to put a piece together to test it for myself. I just hate making these kind of decisions.

To orsonroy:

I am looking forward to seeing your pics as soon as you get a chance to send them to me. My layout is in an approx 15x18 space. I am going to use wall brackets around 3 walls of the room with a 3ft. “hallway” down the 4th side. The 4th side of the layout will be free standing with a “door” built in for access at one end and a peninsula into the ctr. of the room. I’m planning a helix in the center, in order to get high enough for a possible second level around the 3 walls. It is a VERY ambitious undertaking for me. I hope to do it in stages so that if it gets too much for me i can just stop at some point and enjoy it, as is. I think maybe I will put a 2x4 section of the luan and foam together to see how it looks and how strong it is. I’m concerned about having to screw things to the bottom and the edges of the layout and the luan is awfully thin. I think I agree with you about not using L girder construction in the free standing part. I also think I’m beginning to understand the use of the foam better. Again, I thank you for taking the time to try and assist me. I appreciate yours and everyone elses comments and opinions very much.

Richard

11

[quote]
QUOTE: Originally posted by dano99a

Unlike homasote foam does not warp from moisture, humidity any of that… You can carve it, sand it, cut it, glue more foam to it and sand that. It takes most any paint you throw at it (DO NOT USE SPRAY PAINT, it will melt the foam and let off a toxic gas).

You can cut the balast grade out of the foam to avoid buying the cork road bed. But I’ve seen both done well. It’s easy to add and remove trees you just stick em’ in the foam.

Give me a foam blade and sand paper and I can make mountain after mountain within an hour. It’s easy to make rock outcroppings cliffs etc. etc, works great for making nicly poured coal for your hoppers. :slight_smile:

As for being quieter, well I dunno know about that, you get a noisy engine and it doesn’t really matter. It definatly is lighter than using wood,homasote and plaster.

The only problems I have run into (thus far) are:

You can’t use an atlas under the table switch machine (easily), so you have to use ground throws or come up with some crafty method to extend the atlas machine pin or use the table top version but then you have to be crafty to hide those (I came up with a rather interesting solution to this). The other option is to explore other types of switch machines that have a long pin to go through 1/2" of plye wood and 1-1/2 " of foam.

Cutting and sanding that stuff makes the biggest mess in the world. Have a shopvac handy. I cut mine with a foam cutting blade in a utility knife. A hot wire works too but it smells bad because it melts it.

Using tiny nails to hold the track to it will not work forever, I tack it down until I’m happy with it, then I glue it using good ole Elmer’s.

Give this thread time I’m sure many others will add to both sides of the list.

Good Luck, and above all, HAVE FUN

– here’s photos of my layout using foam (pink and blue)
http://www.crtraincrew.com/layouts/dan.

12

Thanks for the compliment! :slight_smile:

Well,I’d say the 1/4 is the way to go, but I also am interested in trying it without the plye wood at all as mentioned above. I figure if you have enough cross beams under the foam then it wouldn’t really matter if you had the plye wood or not. But if you want some kind of base I’d say 1/4, 1/2 is kinda overkill as stated above.

Have fun :slight_smile:

13

locomutt-

I’ll send you an email this evening, I’m replying now cuz I have the laptop handy. so be on the look out, I’ll even send you the link to use that C&O herald.

14

Dano,

A few modelers have used foam without any plywood support at all, and it works well, if you build it a certain way. It all depends on how much construction time you want to put into your basic benchwork.

The “proper” way to build a layout with 2" foam and no underlayment plywood, is to fabricate 1x2 wood L brackets, and attach them directly to a studwall (generally bare, but it doesn’t really matter). Glue the foam to the wood brackets, and screw a backdrop to the studs (on the top level) or the brackets (on lower levels). This method works extremely well, but it does require more time, effort, and money to build. I opted for the most simple method I could think of: U channel, L shaped shelf brackets, screwed directly to the studwall, with plywood between the foam and brackets so I could mechanically attach the layout base to the brackets (drywall screws). It’s cheap, fast, and somewhat stronger than the first method, but it’s not for everyone. Mostly, you can see the brackets on the lower levels, since I didn’t bother trying to hide them behind a backdrop. The backdrop is painted right obver the brackets, which helps hide them, and I’m hiding as many as I can behind buildings and trees. It doesn’t bother me, but might be disconcerting to some.

Either way, experimentation is the only way you’ll really know which method you like the best!

15

Ray -

Thanks for the input, I think I’m gonna try this once I get to building the staging area for my layout.

16

Hi all,
any Aussies out there know where to get the right sort of foam? What is it called? I’m in sunny (and smokey) Brisbane.

17

Sorry but this is not quite true. “I” “personally” have had “great” sucess using oil-based Rustoleum on foam. But (there is always one ain’t there?) it “must” be insulation grade foam (pink stuff). If you try using it on regular foam then you are correct, it “will” melt

18

My layout is now coming to sceneyy stage and uses no wood. I used metal studs and rail(channel). Two inches of foam topped with Homasote sound board (not Homasote). Yards and industry right on top of the sound board, mailine and sidings use Vinylbed roadbed. Acrilic latex caulk holds foam, Vinylbed and can hold track. I use track nails until the track is ballasted then remove the nails which are unnecessary. The 2-5/8" metal studs are assembled as in the MR article in, I believe, the April 2000, issue. With about two feet centers and the metal shelf brackets on 4’ centers. While I haven’t stood on it, I did sit on it without damage. The metal frame doesn’t warp, is straight and doesn’t change as much with temperature. And we have a big difference in temperature here in the Valley of the Sun aka: the Phoenix area. Sound board is less expensive than Homasote, just don’t get the asphalt impregnated kind. The one to use is light tan, a good base color for scenery. It cuts with a sharp utility knife, buy a pack of a hundred blades and change them often as the sound board will dull them after a couple of long cuts. I suppose if you are in a very humid area, you might want to paint both sides of the sound board. Humid here is when it gets to 27%. Oh, material date sheets for Owens-Corning Polystryrene Foam, state that when burned, the material produces CO and Styrene (what most of my cars and structures are made of) 8>).

Rick Ricketts
Gen. Mgr., the AZN, "The Route to Recreation

19

Richard,
I’m just building my first layout, but I will tell you what common sense led me to do. I have just over 8’x8’ with a curvy diagonal cut to fit our living space. I didn’t want to do carpenter work, I just wanted a layout with no harm to the house. Since I couldn’t find straight 4x8 sheets, I bought two particle board sheets 3/8" which turned out to be very strong. On that I glued 5" of foam board, cheap at a building supply, (two 2" and one 1", the beadboard type that everyone says don’t use it, but they also said don’t use particle board). Two sides are velcroed onto window ledges and dowels are the legs which are velcroed to the floor. Moving this layout in two pieces will be light and easy. The foam allows me to have rivers, valleys, trestles, waterfalls, and my engines have no grades to climb, you know like 16 feet to go up 3" and back down. It gives me a 15 foot length of cliffs/rocks at the entire front face along with my waterfall, trestle and mountain stream. I love trains moving along cliffs. Adding or subtracting height is so easy. I used spray paint (acrylic) on the foam to give it a starting color, and used foam glue for my rubber roadbed. The lightness allowed me to have a center cut out of 30 inches which will be my mountain and logging operation when I don’t need it to work from anymore (but it can come out for maintenance issues, since it is all so light).
All that carpenter work scared me into this method, and so far I don’t regret it.
If you have any other questions email me at avsecb2@hotmail.com
Regards,
Reg

20

You can buy sheets of blue foam from Insulation Supplies Australia 330 Curtin Ave, Eagle Farm ph 3268 7399
For offcuts for scenery you can try Reverse Garbage in West End - web address www.reversegarbage.com.au.
Happy hunting from another enjoying sunny Brisbane.