To use foam or not?

[dickiee]

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

[Anonymous]

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

[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. :)

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

[snowey]

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.

[orsonroy]

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 underway!), and it'll easily support two of me. If I need a rise in elevation, I just make sone 2x2 legs a bit taller than others (where the pre-planning comes in handy)

Pictures can be worth 1K words. If you're interested, email me offlist, and I'll email you a few photos of my layout under construction. Foam layout construction may not be for everyone, and it does have some limitations, but for 90% of the layouts out there, it's IMHO the best, fastest and cheapest way to build a layout.

[Anonymous]

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.

[jwmurrayjr]

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.

[:)]

[snowey]

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[:)][:)][:)])

[jwmurrayjr]

QUOTE: Originally posted by snowey

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[:)][:)][:)])

Amen! (What he said!!)

[dickiee]

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

[locomutt]

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. :)

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

You are very correct about using spray paint on the foam,however;sometimes you need that texture. Just be responsible, and do it in well ventilated area.

Most of my scenery is built with foam,I don't think you could use anything easier than that.

I love the C&O for progress emblem you use with the signitaure. I would love to have that
to go along with my signature. I've modeled for over 40 years,and generally it has been the C&O. I've lived in both Raceland and Russell,Ky.and visited Huntington more times
than I can remember. I have a slide of 490 when it was still in Huntington,before it was moved to Baltimore. (about '67-'68)

Please pull up my profile,and give me an e-mail.[:D]

[dano99a]

QUOTE:

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.

Thanks for the compliment! :)

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 :)

[dano99a]

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.

[orsonroy]

QUOTE:
Well,I'd say the 1/4 is the way to go, but I also am interested in trying it without the ply 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.

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!

[dano99a]

Ray -

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

[Alantrains]

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.

[Anonymous]

QUOTE: Originally posted by snowey

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.

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

[cricket]

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

[Anonymous]

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 [e-mail]
Regards,
Reg

[Anonymous]

QUOTE: Originally posted by Alantrains

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.

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.

[fwright]

Has anybody hand laid track directly on foam successfully? I also am re-entering the hobby after about 20 years. My previous layout used L girders, 1/2 in plywood, and a Homasote-like substitute. Plaster scenery on wire (actually fiberglass) screen. Worked well, but too heavy for the bookshelf layout I now envision.

Also, the Homasote-like stuff was only good for 1 track laying exercise. If I had to scrape off the ties to do a scene or track over (or add a turnout) - I used diluted white glue for the ties - the top paper layer of the roadbed which provided most of the holding power and even surface disappeared. It was very difficult to get an even surface again.

Using shelf supports every 16 inches - may need heavier plywood if studs are on 24 inch centers - I intend to try the 1/4 in ply plus 2 inch foam. Question is whether I need Homasote (the real thing this time!) on top to handlay track. I see some folks are spiking into cork roadbed. In the old days, that was trouble because the cork would give over time, and throw things out of guage. With the current practice fo gluing and using much thinner cork, is this still a problem?

Second question - can the 1/4 in ply and 2 in foam sandwich be curved into grades over risers, or do I need to add layers of foam? Is a 1x3 girder in the front sufficient (or overkill) to hide/protect the ply/foam edge and give a lifting point for the shelf /module? Or is 1/4 in ply glued vertically against the foam sufficient here, too.

[orsonroy]

QUOTE:
Has anybody hand laid track directly on foam successfully?

You bet! Several modelers have successfully handlaid track on foam. You just have to think through the problems a little (the only real "problem" being that foam won't hold nails). In general, you have to add something between the foam and the track that will hold the track in place. There's lots of ways to do this. You can either go the traditional route, and add a THIN roadbed material like Homabed or 1/4" Lauan plywood, or you can change the way you handlay track, and either solder all the track to PC board ties or use an epoxy or CA to glue the track down (lots of British modelers handlay using all PC board ties).

QUOTE:
Using shelf supports every 16 inches - may need heavier plywood if studs are on 24 inch centers - I intend to try the 1/4 in ply plus 2 inch foam.

2" foam and 1/4" plywood is more than strong enough with supports every 24". I have a couple of areas of mostly freestanding layout that are built out of 2x2s (either box frame or cantilevered shelves) on 24" centers, and they'll easily support my 225 pounds crawling around on them (to get to the upper levels).

QUOTE:
Question is whether I need Homasote (the real thing this time!) on top to handlay track. I see some folks are spiking into cork roadbed. In the old days, that was trouble because the cork would give over time, and throw things out of guage. With the current practice fo gluing and using much thinner cork, is this still a problem?

Handlaying track and relying on just the cork to hold the spikes is generally a no-no, since the cork itself doesn't hold spikes well. I consider cork to be nothing but a scenic element, and have eliminated it on my layout in favor of handcut roadbed, using 1.5" strips of 1/2" thick foam. I think a different question should be: "why do you want to handlay track?" If you like to, or if it's a budget consideration, that's fine. But if you're looking to handlay track because you think it looks better than commercial track, take a look at Micro Engineering track. It's better than any handlaid track, except the real thing! Using commercial track will eliminate most of your tracklaying issues (just glue and go!). If you really do want to handlay track, I'd suggest eliminating cork altogether, and going with Homabed glued to the foam. And yes, Homasote reacts badly with moisture, so I'd actually suggest not using water on it if at all possible. Paint the Homasote before laying track, use a thin layer of clear silicone caulk adhesive to lay the ties, and test the track extensively before you ballast. That should eliminate all your Homasote "fluffing" issues.

QUOTE:
Second question - can the 1/4 in ply and 2 in foam sandwich be curved into grades over risers, or do I need to add layers of foam?

Actually, you don't need to do either. You mentioned building a shelf layout. My layout is a 12x25 three level shelf layout, and there's not a single riser in the benchwork. I planned out the grades on my layout before I started building benchwork, and just adjusted the shelf brackets to fit. I attached the plywood to the brackets, glued the foam to the plywood, and that was it. Works like a charm. Admittedly, my layout is a pretty simple corkscrew up the walls, but I did come up with plans for a underneath staging area that would have the benchwork go in two different directions on the same level. I still wouldn't have needed any risers.

As for curving the foam, why would you need to? All my basic foam is laid like bookshelves; long and straight. Some of my front edges have since been curved, but that's scenic, not structural. The TRACK should curve around the walls; there's no need for the foam to do so. I do successfully curve 1/2" thick foam all the time. I use it for my roadbed. The 1/2" foam comes with visqueen backing paper, which I leave on while cutting, curving and gluing. Once the glue is dry, I remove the top layer of backing paper, sand the top smooth, and caulk down the track. I've tried removing one or both layers of backing visqueen before I curve the roadbed. It doesn't work. With both layers on, I can curve 1.5" wide pieces of foam down to about 24" radius curves before it starts to crack.

QUOTE:
Is a 1x3 girder in the front sufficient (or overkill) to hide/protect the ply/foam edge and give a lifting point for the shelf /module? Or is 1/4 in ply glued vertically against the foam sufficient here, too?

I'm actually thinking about not adding a fascia at all on my layout. If I do decide on adding a fascia, all I'll do is add a 1x1 along the lower edge of the plywood sub-sub-roadbed, and screw and glue more 1/4" ply (or 1/8" Masonite) to the front of the layout.

Hope this helps! My current layout is the sixth foam layout I've built (one other home layout for me, several modules for a Ntrak layout, and home layouts for three friends), so I've learned a lot about foam layout construction over the past 10 years or so. This is all what's worked for me, or on layouts I've been able to poke around on. There are quite a few modelers on this forum that have built foam layouts, so hopefully they'll have more advice that will help you decide on what's best for you. I'll finish by adding that I've also built traditional L girder and spline layouts with plaster scenery. I'll never go back!

Email me offlist if you'd like me to email you a few photos of my layout in progress.

[Anonymous]

QUOTE: Originally posted by dano99a

.... (DO NOT USE SPRAY PAINT, it will melt the foam and let off a toxic gas).

Well... that's a good rule of thumb, but acrylic sprays would probably work fine... just that most sprays are NOT acrylic.

Also, hazards of foam+heat are immense--- limit your use (thickness and area of coverage) to minimize your risks... need I say: No Smoking! ?

And, as for plaster scenery, (I'm just getting to that point on my layout, so I'm all ears, here) ... consider paper towels (or similar paper) plus diluted white glue (elmer's equivalent). I'm about to start that method to see how it works - (my 4 yr old brought home a craft project that lasted through a bit of rough handling with No structural support!)

And if you're still in the wood adhesive stage, try Titebond WOOD MOLDING glue... (i got it at Home Depot, small packages only - 8 oz, I think) because it Sets FAST and lets you move on to the next joint almost as fast as you can prepare it.

Good luck, and Hope you enjoy it !

[Anonymous]

QUOTE: Originally posted by snowey

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[:)][:)][:)])

I suppose that's how you got the name! [;)]

[jwmurrayjr]

Foam is very versatile and strong when used to form a structure.

You can go from this:


to this:


without any plywood except for the "table tops" on the modules.

This is over 2 years old and is very stable, but it is in a climate controlled room.

[:)]

[Anonymous]

I have developed a simple method for mounting turnouts on a foam layout. I'm using Atlas code 55 N scale turnouts and the new Atlas under table switch machines but you should be able to adapt it to HO. Tortoise switch machines can be used if you prefer. Key to the method is a rectangle of sheet styrene cut to fit the switch machine and the turnout. The turnout is mounted on one side of the styrene with double-sided foam mounting tape. The switch machine is mounted on the other side with adhesive caulk. Foam is removed with a hot knife from the layout to accomdate the switch machine. The whole assembly is then dropped into place and the turnout attached to the track with railjoiners. A little adhesive may be needed around the edge of the styrene to keep it firmly anchored. The turnout assembly is constructed at your workbench and there is no need to crawl under the layout to mount it. Because of the low profile of the Atlas switch machine and the 2" foam which I use as the layout base, the turnouts can be placed anywhere without concern about interfering with cross supports under the layout.

By the way, no plywood being employed in the layout I am building. Two inches of foam have adequate strength to support the layout. Steel studs are used to build open grid benchwork. Photos of the benchwork can be found on the Mississippi Valley N Scale website. http://mvns.railfan.net/augustaphoto3.htm You can navigate to additional pictures of the layout from this page.

Jerry Smith

[cwclark]

I'm still a cork roadbed, plywood kind'a guy but every where else i do use foam..the reason is that i weather the track with spray paint and don't want to melt the foam with krylon oil based paints...I work in a plant near Houston and have an unlimited supply of (free) foam pipe insulation..I carve out rock faces, ravines ,and ditches using the foam and it works like a charm everytime...another thing i like about foam is planting bushes and trees...all you do is pu***hem into the foam...it sure does beat jumping up and down on an awl to cut a hole into plywood...Chuck[:D]

[grayfox1119]

Hi Richard, I too am finally getting to build my 1st layout since boyhood (Raising 4 kids, long hours at work, school, U.S. Army,etc, then grandkids to watch). I have built a dept 56 Christmas village for my wife, and I used the foam that is made for our hobby, from Woodland Scenics. They have some excellent books, and very good VHS videos that really do a nice job illustrating techniques. It is great for us starters or new people to foam.
This layout sits in our Family Room each holiday for about 2 months, so I need to be able to easily remove it. I constructed the framing out of 1x4 pine, and used machine screws and wing nuts for quick and easy assembly/disassembly. The mountains I constructed from the blue 4" foam you find at HD for insulation. I then Used Woodland Scenics foam risers for the HO train that runs through and along the mountain ridges . Because this setup has to be removed each year ( I would leave it up right guys?), I used the woodland scenics pins to hold the track in place. This makes setup and removal quick. The point is (no pun intended) the pins work well. If this were a final setup, the pins hold the curves well until you do the final work on the tracks.
Thanks to you other guys, I have obtained some great info on other materials and methods for constructing my layout support system this Fall.

***

[dickiee]

To all who have answered this post:

I can't tell you how much I have appreciated all the advice and info about foam construction. It has helped me immensely....especially the pictures. I have decided to use a combination of plywood and foam on my layout. I hope to try and use many of the techniques that have been suggested. It should be interesting and fun.

thanks again
Richard

[CBQ_Guy]

You've gotten a lot of good advise here, so there's not much I can add except to consider that when foam burns it gives off toxic, make that lethal fumes!

Second, ignore comments concerning Homasote being affected by water and moisture...just ain't so. I was surprised to see that this model railroad urban legend is still around.

Good luck with your layout!