Can anyone list the advantages and disadvantages of using styrofoam insulation as a base as compared to just using a plain plywood base? What's the best way to attach track to the styrofoam? I'm trying to decide whether or not to go with the foam before laying the track and getting started on the scenery. Any advice/suggestions/ideas would be appreciated. Thanks, Dave.
It's very noisy. We have one NTrak module made with styrofoam (well, extruded poly something blue stuff) and you can tell when a train goes over this module. Railroading on the back of a guitar. Now, if you were to make the sub-roadbed out of plywood and make everything else out of foam, that'd be ideal! :sun:
Tony I agree, especially with Unitrack seems to resonant even more. What thickness of plywood base would you recommend below the extruded foam.
Like most folks, I'd just use the plywood directly under the tracks and foam elsewhere. The new Tehachapi loop at the HO La Mesa layout is being built this way, since a lot of it is cantilevered out over the lower deck. mg: They have switched to box beam construction instead of L Girders, which is good because L Girders are really annoying to get under for wiring with the forest of beams and risers. The thickness of the plywood sub-roadbed will depend on the span you want between risers to support. Our latest modules are only have 1/4" thick tops because they only have to span a foot side to side (oNeTrak), but others use 1/2" thick for 2' or more of span. Some parts of the new La Mesa Yards use a steel box-beam welded table, which spans a clear 8'! Perfect for wiring goobs of switch machines...
My current layout was my first time using foam. I have a 1/2" plywood sub-base over L-girders (leftover from previous layouts and recut) with 2" blue insulating foam as a base over that. I've also used Woodland Scenics foam track bed, glued to the foam--also a first time not to use cork and nails. I've been delighted with how quick and easy this new stuff is to use and have found it MUCH quieter than the old cork nailed to the plywood system.
Here are a few of my thoughts on foam construction: You do NOT want to use STYROFOAM! Styrofoam is the white beaded material you find in coffee cups, cheap coolers and as packing material for appliances, electronic equipment and other items. It is difficult to cut smoothly or sand, it is messy and produces lots of statically charged plastic "sawdust". It can be cut with a hot wire tool but produces potentially hazardous fumes AND it SUPPORTS COMBUSTION!! Once set on fire, it will continue to burn on it's own! The material you want to use is extruded polystyrene. Dow and Corning are the principle manufacturers; one is pink, the other is blue. EPS can be cut with a sharp knife or hot wire tool. It can be cut with a saw but the "sawdust" will be statically charged and hard to deal with. When cut with a hot wire tool, it produces little or no fumes and the fumes are not known to be hazardous. (An aside: ANY fumes produced by heat are probably best avoided, regardless of the material.) EPS does NOT support combustion! It will melt when heat is applied. An open flame will cause it to burn but it will self-extinguish when the flame is removed! Noise reduction is almost a matter of personal preference. I have found plywood to be much noiser than foam. Choice of adhesive may be as important as choice of substrate. Glues that dry hard transmit sound easily; glues that remain pliable after curing transmit less sound. Cork roadbed is more dense than the foam roadbeds such as the Woodland Scenics product. More dense equals more sound transmission. This doesn't mean you shouldn't use cork. Once again, it comes down to the method used to secure it. Hard drying glues will transmit sound. Cork itself is sound deadening, but will transmit sound when glued to a dense surface such as wood. The subsurface is the key to quiet operations. Hard, dense substrates, like plywood, can amplify the sounds passing through it. Wood resonates the sound, which is why musical instruments are made of wood instead of plastic foam. Whether you decide to use wood or foam as a substrate, how you attach the roadbed and track will determine how much sound will resonate through the structure. Use a very thin layer of non-hardening adhesive like latex caulk to attach the roadbed to the substrate and the track to the roadbed. Many modelers use a sandwich of thin plywood with foam laminated on top. If laminated with a non-hardening adhesive, this sandwich construction may help reduce noise transmission because of the different densities of the materials. Having a solid material under the foam provides a good surface for mounting accessories under the layout. Foam is a great product to use for model railroading. Like other products, it has certain performance characteristics that have to be taken into account when using the material. It's light weight and ease of use are it's principle advantages over other materials. These are just a few of my thoughts. I've found foam to be a boon to model railroading and I don't hesitate to use it. Darrell, quiet...for now
Well you better tell Dow, apparently they don't know the name of their own product http://www.dow.com/styrofoam/what.htm
dgwinup, Welcome to Trainboard, and thanks for a very nice discussion on foam board. I used it extensively, many times just like plywood. Parts of my layout use foam board as vertical supports. I think the white bead board is marginally OK in a few situations--and only if you can control the beads. I used some for mountains far away from tracks. I shaped the mountains outdoors. I also covered them with a heavy coat of joint compound because of the fire danger. But I wouldn't recommend it. It's also OK in a monocoque structure--as a filler between two 1/8-inch sheets of plywood, for example. I've made these panels when I had odd shapes, and didn't want to cut up a hollow core door. You essentially end up with a 1-1/4 inch thick panel that can be quite rigid. Nelson, Dow often uses "popular" terms to describe products. Many of their glasses are actually plastics.
On that page, Dow says, "But there isn’t a coffee cup, cooler or packaging material in the world made from STYROFOAM. "These common disposable items are typically white in color and are made of expanded polystyrene beads. They do not provide the insulating value, compressive strength or moisture resistance properties of STYROFOAM products. In order to protect the Dow trademarked name “STYROFOAM”, such other material should be referred to by the generic term “foam.” . . ." So Dow is protecting the use of STYROFOAM. I guess we should start using STYROFOAM in the correct manner--it's their capitalization by the way, part of the branding. Henceforth, I pledge to Dow to use STYROFOAM only for the blue stuff. The pink stuff will be "extruded polystyrene," and the white stuff "expanded polystyrene beads." And I will not use Bandaids, unless they are made by J&J. I will use "flexible adhesive coverings." I missed Nelson's original point--that styrofoam has become as generic as bandaid, xerox, aspirin, google. I learn something every day!
Why use foam....will not drive significiant other to do unwanted things....such as scream and yell, intrroduce us to new words normaly reserved for the Army drill sargent, etc.
Do you have ballast yet? My Dad's HO layout was wonderfully quiet with a foam board with cork on top. Then, we added ballast. When it dried, rolling thunder! mg: Seems that the ballast created a vibration path between the rails and the foam, bypassing the cork's dampening qualities...
I've approached my layout using two different methods on the upper and lower decks. The upper deck is made from 3/4" plywood with a 1/2" homasote sub roadbed glued down. On top of that will either be HO scale cork (1/2 strip) for mainline ballast profile, N scale cork for sidings, or glued directly to the homosote in the main yard. On the lower level I've decided to change things up and start as before with 3/4" plywood, then 1/2" extruded polystyrene (it's pink, which may or may not be STYROFOAM ) then HO scale or N scale cork as before. I'm just about to start laying track on top of the foam board, so we'll see how that performs here shortly.
Guess I'm in for a Noisy Layout: The consesus seems to be that I should put something between either the track and the foam or the foam and the 1x4s.
Hmmmm. No Tony I haven't ballasted yet. Could be in for a surprise huh? Ah well, I should say SO FAR, I'm a happy camper
I've built the 1st floor of my new layout using a combination of 1" pink foam on top of 5/8s plywood in some areas and in other areas just flat plywood. Reasons for using both methods are I wanted some variation in topography in my mountainous areas. With foam you can cut out these variations easily vs. blasting though plywood. The areas dedicated to intermodal, grain ports, and freight yards would normaly be flat so no foam used there. I haven't layed track yet so can't testify as to the difference in sound. I know on my old layout I used cork roadbed glued to plywood and it was noisier than all get out. Switched to plastic wheelsets and that helped somewhat. I've read (here and on other web boards) that you need to use varing densities of roadbed and sub-straight in order to deaden the resonance. (ie. foam roadbed on plywood.) I've used latex caulk to fasten my foam roadbed to the foam surfaces and will use latex caulk to do fasten the track to the roadbed as well. I'm hoping that that will provide the change in density to kill the noise. Will let you know when I get that far.
Since I am just starting my benchwork, I am going to go with the foam over wood slats spaced about 16 inches apart. I checked it out today, there is a difference with the foam only which is ever so slightly noisier.
I think foam board construction is noisy, but I have no idea about whether it's noiser than plywood. By the time I have a scene finished, I have lots of layers. The layers may be hollow core doors, wire racks with foam board, plywood with foam board, or any combination of the above. I do notice that my trains are very quiet when crossing my bridges. That may be the biggest clue to this resonance question.
Wow, it seems as if I've started a controversy about foam. In my original post, I used styrofoam as a generic term. I meant that pink or blue stuff that's used for insulation. Actually I have the track (Bachmann EZ track), nailed to a hollow-core door (36" by 78"). (Don't yell at me, I'm a rookie:angel: .) I don't find it all that noisy. What I was wondering was about using the foam on a second door when I find the room after re-arranging my small apartment, mainly to vary elevations, and was thinking about tearing up the track on the first door and re-laying it on a foam base. I have 33 feet of mainline so far and am about to start doing the scenery. As I find it fairly quiet so far, I think I'll keep the bare door for the first one and try foam on the extension for the elevation changes. On another rookie question, I plan to run only one train at a time on the layout. Can I run it all, about 60 feet of mainline, from one powersource, or will I have to block-wire it? Thanks to everyone for the varied responses; Dave.
I used two inch foam over 3/4 inch plywood. I then placed one inch foam strips under the Unitrack roadbed. The layout is completely ballasted and is very quiet except for the sound That I have on the JJJ&E using sound decoders and four inch speakers under the benchwork. Oh yes, you do hear the metal wheel sets of the rolling stock roll over the track. But you expect that. The foam absorbs most of the extraneous sound, that cork and other sub road beds fail to do. Stay cool and run steam......
Darrell, I think you might haven gotten your facts mixed up. Just trying to clarify since one gives off toxic fumes when using a hot wire cutter and the other does not. This is a safety issue for readers. The pink/blue foam is the one that DOES give off toxic fumes when using a hot wire and is also flammable. The white stuff does NOT give off toxic fumes. I'm not sure about the flammability of the white stuff. Please do not use a hot wire cutter or a hot knife indoors with pink/blue foam.
