Sound Absorbing Layout Materials

[Billybob Reuben]

I am building my first layout and started laying flex track on Woodland Scenics foam roadbed which was placed directly on the 3/4" plywood benchwork. The combination seemed to be very quiet until I glued it all together. Once the glue dried, the sound of a running train increased significantly. I am wondering if I simply used too much glue, but there are no instructions with the foam so the modeler is left to do it on his own. Some literature suggests that a sound absorbing material like Homosote should be installed between the roadbed and the benchwork, but I found that Homosote, celotex and other like materials are all too soft to use for layouts. They don't take spikes and are difficult to cut or shape without falling apart. Does anyone know of any new materials out there that can be installed between the roadbed and the benchwork to reduce the sound of running trains, or is this extra layer of material even necessary. Is there any literature out there that addresses this specific problem? I would appreciate a response from any modeler that has an operating layout and hear how he solved this problem.

BillyBob Reuben

 

[roryglasgow]

BillyBob,

I used the Woodland Scenics Roadbed product, too, but I placed it over an inch of blue foam insulation board, which in turn is on a hollow core door. The roadbed is glued to the foam, and most of the track is simply pinned in place with track nails. I put a dab of glue on the end of each nail to give it an anchor. Everything is very tightly in place.

This foam insulation board comes in blue and pink (and maybe green), and it is sold in various thicknesses. I think I got a 4'x8'x.5" thick sheet of it for around $7 or $8. I've also used the bead styrofoam stuff, but it just seemed to amplify the sound. Plus, it's really messy to cut. The insulation board stuff is more solid, so you don't get a snowstorm whenever you hack a piece off.

About the only noise I hear on my layout is the sound of the axles turning on the rolling stock and the noise of the locomotives. Oh, and I sometimes hear a mysterious groan from a car or two as they go round one bend...strange...

-Rory

 

[Matthyro]

We don't want them to be too quiet do we? Just stand near a prototype crossing when a freight goes by and you can't hear yourself think. If it just sounds hollow BillyBob, then you may want to stiffen the plywood underbase by putting some cross beams underneath it. Spikes going through the track bed can be removed after the track is ballasted and that will also make a difference as the spikes will transmit sound down to the plywood.
Like Rory, I use foam between plywood and the cork track bed I use. I use 1/2 inch foam.

 

[Bob Collins]

I too am using blueboard and Woodland Scenics foam. I don't see where you make any mention of cork or any other kind of roadbed. Did you lay the track directly on the foam?

I don't feel like I have any excess noise, but understand that when I begin to put down ballast there may be an incease in the noise level??

Bob

 

[Billybob Reuben]

Yes, I laid Shinhara flex track directly on the Woodland Scenics foam roadbed on top of 3/4" ply, and when the glue dried, running a train on it was very noisy. Since I use only metal wheels, no plastic, the noise seems excessive.

Before I decided to use the foam roadbed, I went to our local Home Depot and bought a sheet of commerical 3/16" cork which is roughly the same thickness as the Woodland Scenics foam and laid a section on track on that, but to my ears the foam was much quieter than the cork which created a high-pitched whining sound I did not like. I also tried 1/4 inch Atlas pre-formed cork roadbed which did not seem to improve the sound any over the 3/16" cork from Home depot.

I know a lot of modelers use homosote and celotex type materials between the roadbed and the benchwork, but I find these materials extremely messy to work with, they flake and break when being cut or shaped and the little pieces get into everything, including your nose and eyes, and although I know of no health hazards associated with the materials, I personally don't see where they could be worth the unpleasant side-effects.
A friend then mentioned an artile that appeared in Model Railroader a few years ago about a product called Micore 300 which apparently is much like Homosote and celotex, but when I checked with my local lumber yard I was told that they do not carry Micore because it is made of slag, is listed as a hazardous health material and is suspected of being carcinogenic. So much for advice from Model Railroader!

The blue insulation board sounds like a good idea to me so I think I will try it next.

Thank you, guys, for all the advice. Being a novice, I need all I can get.

BillyBob

 

[Billybob Reuben]

Before I forget to mention it again, yes, I did put 1x4 inch pine stiffeners under the 3/4 inch ply and spaced them about every 16 inches, so that should at least help eliminate the "drum" effect that unsupported plywood can create.

 

[Catt]

I think you may find that your stiffeners while strengthening the plywood has infact seperated your layout in to seperate sound boxes.What you could try is installing angled pieces of the 1x4 between the stiffeners but not attached to them.Something like this l/ l.This will in effect break up the sound boxes and help baffle the sound.

 

[Gary Pfeil]

I can't comment on using foam for roadbed, but since so many others have that's ok I guess. I must be getting old enough to start resisting new ideas! Anyway, the cost of the woodland scenics riser system is enough to keep me away from it. The reason for this post is actually to contest the statement that homasote is too soft to hold spikes. This is simply not true. I handlay my track on homasote precisely because of its spike holding abilities. It not only holds them firm, but allows spiking without bending spikes or requiring predrilled holes. Cutting the 4x8 sheets to shape is messy however. About a year ago I started using a product called Homa-bed. This is similar to cork roadbed, but made from homasote. I glue this to plywood subroadbed supported by risers from L girder benchwork. I consider the operation rather quiet.

Gary