Trains.com

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Questions about using styrofoam.

14568 views
41 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    July 2007
  • From: Maine
  • 188 posts
Questions about using styrofoam.
Posted by mainetrains on Monday, September 15, 2008 2:07 PM

Getting ready to start a new HO layout and have a couple of questions for those who have used styrofoam. Since my carpentry skills aren't all that great I figure using styrofoam on top of plywood will give me the terrain variations I would like to get. First question is how do you handle turnouts? Seems to me they would all have to be manual or the less than prototypical above the table switch machines.

My other question is how do you get a smooth elevation transition? Carving? The tried and true tape and paper with whatever on top?

I'm sure I should have more questions but that's it for now.

 

'there's something happening here, what it is ain't exactly clear' Modeling the Hard Knox Valley Railroad in HO scale http://photos.hardknoxvalley.com/

  • Member since
    April 2003
  • From: Clinton, MO, US
  • 4,261 posts
Posted by Medina1128 on Monday, September 15, 2008 3:06 PM

I've used stryofoam, quite successfully, too. I cut an offset joint to help align it. As far as turnouts, I used RTS 8.0 (free download from atlasrr.com), and printed out templates of turnouts. I then glue them to the styrofoam with diluted white glue. I then trace out the track to join them, then connect them with flex-trak.

  • Member since
    January 2007
  • From: Eastern Shore Virginia
  • 3,290 posts
Posted by gandydancer19 on Monday, September 15, 2008 3:46 PM

I am building my layout on one inch thick foam glued to Luan plywood. I am using Tortoise machines mounted under the Luan. You have to make a hole through the foam and the Luan/plywood. I start by making the hole in the foam with a Tipi Hot wire cutter. Then I just drill the hole in the Luan from the top with a standard drill bit of the correct size. I replace the .025 diameter actuating wire that comes with the Tortoise with a heavier one, around .032 in diameter, and longer, so that it will reach the throw bar of the turnout.

You can also use Caboose Industries ground throws at or near the edge of the layout by making a grove in the foam from the throw bar to the ground throw. Then connect the two with a wire that is run through a tube of some sort. Cover the tube and grove with caulking and scenic as usual. You should mount the ground throw on a small piece of Luan inset in the foam so the top of the wood is level with the foam. The wood piece can be glued to the foam with two part epoxy.

For transitions or grades, I use stacked one-inch or half-inch foam. When the glue is really dry, I roughly carve the grade with a knife that has a long blade. Keep checking your work with a straightedge of some kind. A ruler or yardstick works well. Second shaping is with a Sure Form tool. keep checking with the straight edge. Last, I use a whole piece of 60 grit sand paper on a foot long sanding block (made from a 1x4) This last sanding should take out the high spots. You just have to take your time.

If you wanted, you could also buy the Woodland Scenics foam grade packs, then you wouldn't have to do all that carving. However, the carving will allow you to learn how to carve the foam better and faster and will be a skill that you will always use for foam, and it will save you money.

Elmer.

The above is my opinion, from an active and experienced Model Railroader in N scale and HO since 1961.

(Modeling Freelance, Eastern US, HO scale, in 1962, with NCE DCC for locomotive control and a stand alone LocoNet for block detection and signals.) http://waynes-trains.com/ at home, and N scale at the Club.

  • Member since
    November 2002
  • From: Colorado
  • 4,075 posts
Posted by fwright on Monday, September 15, 2008 4:03 PM
 mainetrains wrote:

Getting ready to start a new HO layout and have a couple of questions for those who have used styrofoam. Since my carpentry skills aren't all that great I figure using styrofoam on top of plywood will give me the terrain variations I would like to get. First question is how do you handle turnouts? Seems to me they would all have to be manual or the less than prototypical above the table switch machines.

My other question is how do you get a smooth elevation transition? Carving? The tried and true tape and paper with whatever on top?

I'm sure I should have more questions but that's it for now.

I'm getting to start my next layout myself.  It was supposed to be a limited test track that could be stored vertically when not in use, but somehow grew to be a 4 x 6 ft display layout and test track.

Having built several layouts ranging from 3.5x5 to 4x8 with either plywood on L girder, plywood on butted girder, and foam in girder, I don't see a lot of advantages for foam compared with cookie cutter plywood.  This, despite having already bought the 2" foam and 1/4" plywood underlay for the about-to-start 4x6.  I am definitely having 2nd thoughts, and considering returning the foam to exchange for 1/2" plywood (no difference in price in my neck of the woods!).

If portability is needed, then foam is absolutely the way to go.  My foam layout was so much easier to handle than my plywood layouts.

I do not see running a jig saw through the plywood and Homasote to cut out the roadbed, followed by plaster over window screen as more difficult than carving foam.  In fact, it seems much easier.  Both are inherently messy.  But to me, the difference is in how the scenery is shaped.  With foam, you are subtracting by carving.  With screen and plaster (or other plaster shell techniques), you are adding until you get the desired scenic effect.  It is easier for me to visualize what must be done to get the desired result by adding a little than to visualize what something will look like when I subtract some material.

In L girder and cookie cutter, precise carpentry is not required - good thing for me, I feel real good if my carpentry leaves gaps of 1/8" or less.  The only time precision is required is setting up the risers and cleats for smooth grades or level track.  I handle that by clamping the riser/cleat combo in place and adjusting until things are just right.  Then when I have the adjustments right, I drill and screw while the clamp holds the adjustment.

As you have surmised, getting smooth grades with foam isn't quite as easy.  Carving a smooth grades without dips or humps, and level crossways is beyond my skill level.  One common way out is to use Woodland Scenics risers.  It's still difficult to get as smooth a vertical transition as you get automatically with bent plywood.  Another less common method is cookie cutter with flat foam using risers, just like with plywood.  I don't know how well foam cookie cutter works after you get more than a 1" foam/ 1/4" plywood sandwich.  BTW, risers don't have to be wood verticals.

Others, I'm sure, will detail how to make switch machines work with the foam thickness.  I used manual throws, so the thickness wasn't a big deal.

Again, IMHO, the benefits of foam only outweigh its disadvantages over more traditional construction when a layout has to be moved, stored, or carried.  If my 4x6 is going to be moved to display it, or actually be a test track, I should use foam.  Otherwise, L girder and cookie cutter plywood is pretty simple for even a non-carpenter like me.

my thoughts, your choices

Fred W

  • Member since
    December 2004
  • From: Bedford, MA, USA
  • 21,419 posts
Posted by MisterBeasley on Monday, September 15, 2008 4:57 PM

I love foam as a construction material and layout base.  I don't use plywood at all.  I've got a lightweight wood frame and my layout base is all 2-inch foam.  It's stiff enough to easily span my 16-inch supports without a hint of sagging.  (I model HO.)  You can't climb on foam, though, so plan accordingly.  It will not support much weight, and will either crack or crush if you try it.

I do use mostly Atlas turnouts, but I hide the machines under scenery of various types.  More recently, though, I've come to prefer Peco turnouts.  The Peco machines mount directly to the underside of the turnout, and can then be slipped into a hole cut in the foam.  Both Atlas and Peco are twin-coil machines, not as nice as Tortoises, though.

Welcome aboard, by the way.  My LHS (Local Hobby Shop) is Maine Trains in Chelmsford, Massachusetts, and I decided to honor this fine establishment by putting a train shop on my own layout:

 

It takes an iron man to play with a toy iron horse. 

  • Member since
    November 2001
  • From: US
  • 1,720 posts
Posted by MAbruce on Tuesday, September 16, 2008 3:26 PM
 mainetrains wrote:

My other question is how do you get a smooth elevation transition? Carving? The tried and true tape and paper with whatever on top?

I used the Woodland Scenics Inclines.  While I'm generally not a big fan of their overpriced products, I have to admit that this is a very useful product:

http://www.woodlandscenics.com/items.cfm/Inclines

 

  • Member since
    January 2005
  • From: Southern Colorado
  • 752 posts
Posted by jxtrrx on Tuesday, September 16, 2008 4:26 PM

I'm not a big fan of the foam either.  I have used it, and have gone back to good ol' plywood for my new layout.  Unless you need the light weight, I can't see any advantage that's worth  giving up the strength, the ability to easily use under table switch machines, ability to drill a hold that will solidly hold a tree trunk, ability to tack track in case you might want to change it later ( I even tack road bed), something to tack cable ties to underneath for wiring.

Plus, styrofoam is really trouble --- crumbly and unstable.  If you are really attached to the foam idea, use extruded foam -- available in several thicknesses, but expensive.

I do agree, though, that the WS foam risers are NICE (fool proof) for inclines.

-Jack My shareware model railroad inventory software: http://www.yardofficesoftware.com My layout photos: http://s8.photobucket.com/albums/a33/jxtrrx/JacksLayout/
  • Member since
    July 2004
  • From: Carmichael, CA
  • 8,055 posts
Posted by twhite on Tuesday, September 16, 2008 7:21 PM

Given the pros and cons of foam, I will admit that I'm the same as Mr. Beasely--my layout is built on 2x2" lumber supports, using 2" EXTRUDED foam as the base.  I've set my cross-braces about 12" apart for support.  For the grades, I've used the WS styrofoam inclines--the Yuba River Sub rises from 0" in the yard to almost 24" at the highest point, and it's all foam.  No problems in the past 7 years since I set down the original track.  And I run long, HEAVY trains. 

But I strongly suggest using the EXTRUDED foam as your base--it cuts and carves better, and is certainly less messy to work with.  Styrofoam can be utilized for whatever 'undulating' scenery you choose, but as a base it's not really what I'd want to work with--besides, it's not nearly as strong as extruded because of the 'bubble' makeup.  Extruded foam is far more solid, styrofoam is made of tiny foam 'bubbles' that will detach the minute you start carving it (even using a 'hot' knife) and just cause an awful mess.  Use the styrofoam for your scenery forms (and have a vacuum cleaner handy) and the extruded foam as your base.  

On my Yuba River Sub, I've only used styrofoam as my track base, and then only the WS risers.  Any scenery I've done with foam, I've either used the extruded stacked or in most cases, simply used the extruded as 'forms' for mountains, which have been constructed with newspaper forms covered by carpenter's tape, plaster cloth and Sculptamold for strength. 

It's worked for me.  Extruded foam is lightweight and surprisingly strong once it's braced properly.  And the WS styrofoam risers make for extremely accurate grades.  If you want proof, you can check my two web-sites at the bottom of my post.  It's all built on foam. 

But when it comes to a foam base, don't get EXTRUDED confused with Styrofoam.  Believe me, it's two different things, entirely.   

 

Tom Smile [:)] 

  • Member since
    August 2003
  • From: Cherry Valley, Ma
  • 3,674 posts
Posted by grayfox1119 on Tuesday, September 16, 2008 7:31 PM
I am using 2" foam on top of 3/4" plywood. I want the strength and rigidity of plywood, and the ease of shaping and building any touraine that you obtain with foam. To shape the foam for inclines, I pencil the incline on the horizontal side of the foam, and then use a hot wire tool to melt the foam. No cutting, no mess. Then I use sculptamold over the slope-cut to level the track bed. If I manage to do a neat wire cut job, I only have to do a little sanding, but this is not always the case.
Dick If you do what you always did, you'll get what you always got!! Learn from the mistakes of others, trust me........you can't live long enough to make all the mistakes yourself, I tried !! Picture album at :http://www.railimages.com/gallery/dickjubinville Picture album at:http://community.webshots.com/user/dickj19 local weather www.weatherlink.com/user/grayfox1119
  • Member since
    October 2003
  • From: Southwest US
  • 438 posts
Posted by Bikerdad on Tuesday, September 16, 2008 7:48 PM

CORRECTION:  STYROFOAM is a trademarked brand name owned by Dow Chemical for their extruded polystyrene product, a product first brought to market by Dow.  The shortcomings of "styrofoam" described by twhite are the shortcomings of expanded polystyrene, aka "bead foam", not of STYROFOAM.  The common usage of the term "styrofoam" to describe bead foams doesn't give folks license to malign the real thing.

http://building.dow.com/styrofoam/what.htm

And that, folks, is the crux of the matter.  Real Styrofoam can be mighty tough and strong stuff, and even the "light duty" stuff used for wall insulation is much stouter than the bead foams.

If it ain't blue, it ain't STYROFOAM.  The pink stuff (Owens Corning's expanded polystyrene product) is just as good as STYROFOAM.

In the interests of full disclosure, I am not, nor have I ever been, an employee, shareholder, consultant, or otherwise associated in any way with Dow, Owens Corning, or any other EPS manufacturer, supplier, distributor, retailer, etc, except as a retail customer.  I just get annoyed with very bad info.

  • Member since
    October 2005
  • From: Ulster Co. NY
  • 1,464 posts
Posted by larak on Tuesday, September 16, 2008 10:50 PM

A couple of comments from my personal experience with extruded foam over 3/8" plywood:

Cookie cutter works fine for 1% and even 2% grades. 

Tortoises with a longer wire of .039" diameter and a half inch hole work very well even through two inches of foam.

When trying to cut a foam wedge, mark and cut it as well as you can, then use the UNCUT side on top and the imperfect cut side in a thin bed of caulk on the bottom. 

You can use a WS incline under a piece of extruded foam or plywood too. 

In short, OP, you need not worry about whether it will work.

Karl

The mind is like a parachute. It works better when it's open.  www.stremy.net

  • Member since
    August 2003
  • From: Cherry Valley, Ma
  • 3,674 posts
Posted by grayfox1119 on Wednesday, September 17, 2008 9:45 AM
And don't throw away any of the cut pieces for foam, many of them can be used as socks and boulders of various sizes.
Dick If you do what you always did, you'll get what you always got!! Learn from the mistakes of others, trust me........you can't live long enough to make all the mistakes yourself, I tried !! Picture album at :http://www.railimages.com/gallery/dickjubinville Picture album at:http://community.webshots.com/user/dickj19 local weather www.weatherlink.com/user/grayfox1119
  • Member since
    July 2004
  • From: Carmichael, CA
  • 8,055 posts
Posted by twhite on Thursday, September 18, 2008 4:43 PM

Bikerdad--

Thanks for the clarification between styrofoam and 'beaded' foam.  I had always been told that the 'beaded' was styrofoam and the non-beaded was simply called 'extruded' foam.  Didn't know that Dow had been using Styrofoam as a corporate name for their blue extruded foam. 

Sure is good stuff.  Now if I didn't have to travel miles and miles here in SunnyCal to get it, it would sure make it easier.  Evidently the extruded foam causes cancer in Spotted Owls or something, out here, LOL!

Tom  

 

  • Member since
    October 2003
  • From: Southwest US
  • 438 posts
Posted by Bikerdad on Monday, September 22, 2008 7:08 PM

Tom, you're welcome.

Regretfully, while I enjoy blaming every shortcoming of California on the various fruits, nuts and other assorted human oddities y'all have scampering about down there, the relative dearth of Styrofoam and other extruded foams in SoCal has little to do with the various emanations of the People's Republic of California's love for regulation.  'Tis pretty much just a market thing.  The expanded (i.e. bead foam) is far more susceptible to frost damage than extruded, so extruded foam rules in the Frost Belt.  Down in the Sunbelt, the lower cost of bead foam gives it the advantage, big time.  In short, can't be puttin' this one on the poor Spotted Owl, or even the lesser known yet even more nefarious Pearson's Milkvetch Weed!  (Just ask any long time SoCal off-roader ....)

In case you didn't know, there's a place over in the San Fernando Valley that supplies extruded, expanded, closed cell, open cell, pretty much any type of foam you can think of, to the entertainment industry.  (Duck, they're throwing foam boulders at us!!)  If you're ever in the area, you might want to check 'em out and report back to let the rest of us know what they've really got there.

  • Member since
    June 2005
  • From: Long Beach, CA
  • 207 posts
Posted by pathvet9 on Wednesday, September 24, 2008 6:32 PM

Bikerdad - is that the place in Burbank? - the name and address escaped me now - but anyway, I called them and they want $40 for a 2x8' piece of 2" Styrofoam - but they have it and many other sizes. Wish I could remember the name?     Sigh [sigh]

So I am cheap. I waited until my camping trip to Eastern Sierras and stopped in Bishop, found 4x8' 2" sheet for the $40 - STILL TOO Expensive compared to the East but ----- to live in a moderate climate!    Whistling [:-^]

Cheers, Jake ---------------------------------------- Patience when resources are limited
  • Member since
    July 2004
  • From: Carmichael, CA
  • 8,055 posts
Posted by twhite on Thursday, September 25, 2008 12:15 PM

Jake--

Whoah, FORTY DOLLARS!?  Back in the good ol' days six years ago here in NorthernCal, at least in Sacramento, you could get it for about $8, until Home Depot stopped carrying it and substituted the 'beaded' variety instead. 

SOMEBODY'S making a killing--unfortunately, it's not the hobbyist who likes to use it! Grumpy [|(]

Tom

  • Member since
    December 2001
  • From: Northern CA Bay Area
  • 4,387 posts
Posted by cuyama on Thursday, September 25, 2008 12:39 PM

It seems the question of where to find extruded foam in CA comes up every week . It's available, though not widely, for the reasons noted above. I've been told it is often used with radiant heat floors, which are virtually unknown in mild-winter areas like most of CA. Here's what I wrote the last time the question came up, with a reference to the thread on finding foam:

 cuyama wrote:

This comes up pretty often. Here's a past thread where I describe how some of my clients and friends have been able to find the foam, even in mild-winter areas -- and yes, even in California.

http://cs.trains.com/forums/1270007/ShowPost.aspx

The key is to use Dow or Corning's dealer finders and then to call first. The dealer finders will list dozens of Lowe's and Home Depots that do not actually carry the foam. Don't waste your time with them. Instead, try the contractor supply houses, insulation suppliers, etc. But call first before driving!

In SoCal, you may be thinking of:

Foam Sales and Marketing
1005 West Isabel Street
Burbank, California 91506

Telephone: 818 558 5717

As always, call first before driving.

Byron
Model RR Blog

 

  • Member since
    June 2005
  • From: Long Beach, CA
  • 207 posts
Posted by pathvet9 on Friday, September 26, 2008 2:00 PM

Byron - thanks for jogging my memory and I will add that address to the database as I still may need to visit them soon.

Bow [bow]

Cheers, Jake ---------------------------------------- Patience when resources are limited
  • Member since
    July 2004
  • From: Ft Wayne IN
  • 332 posts
Posted by BRJN on Friday, September 26, 2008 10:48 PM
If you are going to use foam (and it makes basic scenic forming easy), use the extruded insulation stuff.  DO NOT use the beady kind of styrofoam.  I did, and now I get little beads on the floor whenever I lean over the edge of the layout.  It's getting hard to keep the floor neat (even though it's in the XLcloset/garage and 'neat' is a relative term).  If you do use beady foam, expect to have to completely contain it inside a fascia or something that will prevent unwanted friction with any moving objects.
Modeling 1900 (more or less)
  • Member since
    July 2006
  • From: west coast
  • 7,632 posts
Posted by rrebell on Sunday, September 28, 2008 1:07 AM
The beaded stuff from HD works fine as a base as long as you don't try to go beyond 2feet by 4feed which is one of the sizes it comes in (2'' thick by the way). then just use scrape foam to build mountains and stuff (cut with some form of hot wire) but as the last post stated, it only works if you intend to cover all surfaces. Woodland scenics inclines are the way to go but buy the starter inclines for the most part as they are fairly cheap and you can use scrap foam as base for each step up. Use siliconized latex caulk for everything including gluing your frame to your foam. you can use white for all (including your cork, if that's your choice) but use clear when you caulk your track down. Use the caulk sparingly for all but the inclines, except for the thinnest part.
  • Member since
    October 2005
  • From: Nashua, NH
  • 430 posts
Posted by Cannoli on Monday, September 29, 2008 11:17 AM
 MAbruce wrote:
 mainetrains wrote:

My other question is how do you get a smooth elevation transition? Carving? The tried and true tape and paper with whatever on top?

I used the Woodland Scenics Inclines.  While I'm generally not a big fan of their overpriced products, I have to admit that this is a very useful product:

http://www.woodlandscenics.com/items.cfm/Inclines

 

This is what I'm doing for the inclines on my own layout as well. My benchwork is in the form of 2'x4' modules built from 1x4 lumber with 2" foam insulation board mounted to the top with latex caulk for the scenery base. I'm then using additional 1" and 2" foam pieces for the raised scenery along with the Woodland Scenics risers to get the track to the correct height.

Modeling the fictional B&M Dowe, NH branch in the early 50's.

  • Member since
    July 2006
  • From: west coast
  • 7,632 posts
Posted by rrebell on Monday, September 29, 2008 1:44 PM
exactly what I'm doing, what type of legs you using and how are you running your track ? Last what are you doing for corner modules as havn't done those yet but one is coming up fast!
  • Member since
    October 2006
  • 520 posts
Posted by Loco on Monday, September 29, 2008 3:28 PM
I just checked with our LHS (Local Hardware Store :P ) and a 4x8 2" of pink is $25.
LAte Loco
  • Member since
    June 2005
  • From: Long Beach, CA
  • 207 posts
Posted by pathvet9 on Monday, September 29, 2008 4:20 PM
Loco - where are you located?   LA?     Cool [8D]   
Cheers, Jake ---------------------------------------- Patience when resources are limited
  • Member since
    July 2006
  • 32 posts
Posted by MECman on Monday, September 29, 2008 5:33 PM
Hi,

Does it bother any foam users that the product is flammable and and gives off highly toxic gas when burning. Building codes require foam to be hidden behind a gypsum drywall fire barrier. Just food for thought.

David
  • Member since
    October 2006
  • 520 posts
Posted by Loco on Monday, September 29, 2008 5:54 PM
I'm still in the process of moving - sort of.  Have to hire a moving company to get the rest of my stuff out of Glendale.  So, yah, from LA.  I'm out side of Columbia Mo. right now.  I've been by Foam Sales, and when I talked with one of the guys there they will sometimes have odds and such, but keep in mind they have a buch of speciality foam items.... got a price list from him, somewhere in a box.  Been unpacking and will keep a lookout for it.
LAte Loco
  • Member since
    July 2006
  • From: west coast
  • 7,632 posts
Posted by rrebell on Monday, September 29, 2008 5:57 PM
 MECman wrote:
Hi,

Does it bother any foam users that the product is flammable and and gives off highly toxic gas when burning. Building codes require foam to be hidden behind a gypsum drywall fire barrier. Just food for thought.

David
Foam tends to  melt and requires a constant flame to burn well, this has been researched well. Looked for the article I read by a fire department on foam and its safety but could not find but it said they had no problem with using it for model railroad construction.
  • Member since
    July 2006
  • 32 posts
Posted by MECman on Tuesday, September 30, 2008 5:02 AM
rrebell,

Thanks, that is reassuring!

David
  • Member since
    September 2008
  • From: Midwest U.S.
  • 4 posts
Posted by middwest rookie on Tuesday, September 30, 2008 8:53 AM

 MECman wrote:
Hi,

Does it bother any foam users that the product is flammable and and gives off highly toxic gas when burning. Building codes require foam to be hidden behind a gypsum drywall fire barrier. Just food for thought.

David

 Nope. I don't plan on burning it. Wink [;)] Besides, as a 911 police and fire dispatcher, I'm sure I could get them to my place in about 90 seconds if need be...

Yes, I am aware that it is "midwest", not "middwest". Thank you for typos during forum registration.
  • Member since
    October 2006
  • From: Prescott, AZ
  • 1,736 posts
Posted by Midnight Railroader on Tuesday, September 30, 2008 9:03 AM
 MECman wrote:
Hi,

Does it bother any foam users that the product is flammable and and gives off highly toxic gas when burning. Building codes require foam to be hidden behind a gypsum drywall fire barrier. Just food for thought.

David
No, I have lots of flammable stuff in my home, including products that would give off toxic fumes if burned. I'm not going to worry about this.

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Users Online

There are no community member online

Search the Community

ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT
Model Railroader Newsletter See all
Sign up for our FREE e-newsletter and get model railroad news in your inbox!