Sill Foam for Noise Reduction

Chuck, good thought.  I often wondered if that would work OK.  Please keep us posted.

It will be interesting to see how this works out for you. Please keep us posted.

Worth a shot, it seems like sill foam would be too thin for real sound deadening.

 

Having said that, the majority of layout " noise" is transferred from the track to the plywood top. I don't see a real issue with noise transfer to the framework, especially if the noise is "deadened"at the top where it originates.

 

Layout noise isn't wood on wood, rather track on wood.

 

The cork roadbed is doing far more to reduce the noise, and obviously, the homasote between the cork and plywood top should eliminate whatever noise (if any) is there with the cork alone.

 

 

 

It's worth a shot.

I don't know if is still available but there is a product called Homabed that is homosote shaped roadbed. I used some on a straight section on the layout and it really lowers the noise there, but due to the poor availability of the product I settled on using Midwest (Rubberized) Cork. MWC does reduce noise but not like the box of Homabed that I had. As for your idea with the sill foam; it should work some (never tried it) but the musical instrument called the plywood table top is where the noise comes from. On my layout I run four trains simultaneously and just accept the noise as being inherent with the product.

every little bit helps Chuck. I think the best thing you can do is make the whole room more sound absorbent. the acoustics of the room itself will determine your overall noise level. I was never a fan of homosote unless you are going to put it on the walls of the room to absorb sound.

I used sill gasket under my track in my tunnels and it works as well as expensive foam roadbed.  I only used it where it can't be seen as it does not have a beveled profile for ballast.  It will definitely reduce sound levels very well.

 

Art

I do not have any experience in trying to reduce noise from trains. I do however think a lot about how I can transfer some of my experience with sound control in recording studio construction into effective choices for my future layout. It seems to me that the noise of trains on a plywood table can be exacerbated in two possible ways:

1 Reflection- meaning the sound is bouncing off off the smooth tabletop, as opposed to being absorbed by it. As this situation is usually controlled by acoustical insulation, I have no idea how it can be helped with a train layout.

2 Transference - The plywood table top, is really similar to the construction of an acoustic guitar top. It's a thin piece of wood set over bracing. I don't doubt that in some instances you can transfer enough energy into the table top to get it vibrating, whereby it acts like a diaphragm and amplifies the noise. This problem of course can be solved in two ways. Decoupling of the track and table with effective roadbed, or by making a firmer top which is more vibration resistant.  

Chuck,

   Having been down the sill foam route one time, IMO you will be much better off

purchasing some acoustical ceiling tile, it is easy to work with and really does deaded the layout running noise.  If you can get some used stuff it becomes a cheap way to construct your layout bed.  We actually stained it green one time leaving different areas on the layout white for a snow patch effect.  I do believe you will be disappointed with the sill foam idea, once you hear how little it deadens the noise level while running.

PCRR/Dave 

I think the sill foam will be too thin to reduce track noise unless you do several layers of it. I managed to acquire quite a bit of 1/2" thick black foam rectangle sheets ( like air conditioning filter foam but thicker & more firmer but still has some softness to it) and I cut it 1/2" wider than the Fastrack on both sides, keeps the track from flexing too much, just a soft dip as the train runs over it.  I glue the bottom of the foam down with foam glue, run my track feeder wires to the track,  then again using the foam glue I glue the bottom of the Fastrack or Realtrax to the top of the foam centered on the foam so there's a 1/2" overhang of foam on both sides of the track.  Only places I screw track to plywood is track siding end bumpers. All my curves are either Realtrax O-31 or Fastrack O-36 and have had no problems with track or foam coming apart or derailment but it greatly reduces track noise. The secret is not screwing track to plywood as that is what transfers the noise, if I didn't have the sheets of foam to use I had thought about using silicone to glue the track down but it still would have been a sound barrier by not using screws,  I just use  the Realtrax for O-31 curves inside the O-36 Fastrack Curves with the Realtrax Adapter Track to Fastrack Transition Track ( I do use silicone to glue those together because they don't fit tight together ) otherwise my layout when finished with be all Fastrack.

 

An often overlooked hindrance to sound control are the screws that are used to hold the track down and the stone ballast. The screws are conductor paths while the stone ballast acts as a resonator.  When multiple trains are running the sounds control part becomes ever more challenging. I damper the sound as much as I can by using rubberized cork roadbed and just live with the sounds of model railroading.

"2 Transference - The plywood table top, is really similar to the construction of an acoustic guitar top. It's a thin piece of wood set over bracing. I don't doubt that in some instances you can transfer enough energy into the table top to get it vibrating, whereby it acts like a diaphragm and amplifies the noise. This problem of course can be solved in two ways. Decoupling of the track and table with effective roadbed, or by making a firmer top which is more vibration resistant."

 

Total agree. The foam to me would insulate the wood to the frame, but the noise will probably still be there if the track is screwed down. Call me crazy, but I used Homosote on top and under the plywood of my layout. It is only 4x8 but works very good for using FT.

Sound input guys. (oy!) I have no illusions about eliminating sound issues, but am hoping that the sill foam between table top, frame and cleats will help a bit. Also, using the foam squares as 'foam washers' might make a marginal improvement.  The layout will be on a Pergo floor so I have put a layer of felt on the bottom of the legs. Again, hoping every little bit helps. 

I am just trying to avoid cutting my 4 sheets of Homosote, thus eliminating the mess. I might just put them on the Buy-sell board for local guys in the near future.

sounds like a new approach to me……..   GO FOR IT….. if it don't work rip it out…..