I CURRENTLY MODEL THE LV AND UP ON MY DEDICATED SHORT LINE, N SCALE LAYOUT. THE LAYOUTS NO BIGGER THEN 4 X 3 1/2. I AM USING THE POPULAR BLUE FOAM ISULATION BOARD, AND FLEX TRACK FOR THE MAIN LINE AND INDUSTRIAL SPURS. I DIDN’T CHOOSE TO GO WITH ANY TYPE OF ROAD BED, MAINLY BECAUSE ITS A PRESEN’T DAY RAILROAD, AND IN THE EASTON REIGON OF PA, BALLASTING IS AT A MINIMAL , MAINLY OVERGROWN WITH WEEDS GRASS, ETC, SO I WAS REALLY LOOKING FOR A RUN DOWN LOOK. I DECIDED TO START THE JOY OF BALLASTING USING THE VERY FINE BLACK CINDERS, THAT MOSTLY REPRESENTED THE DARK BALLAST FROM AROUND HERE. I STARTED OFF DOING THE HARDEST SECTION FIRST. AFTER ALL WAS DRIED, AND I MADE SURE THAT NONE OF THE TIENY WEENY PIECES WERE CLEARED OF THE SIDES AND RAIL HEADS I DECIDED TO ATTEMPT THE DREADED FRIST RUN. EVERYTHING WENT PRETTY FINE, A LITTLE STUTTER FROM SOME LEFT OVER GLUE, HOWEVER I NOTICED THAT THE LITTLE N SCALE ENGINE SOUNDED LIKE AN O SCALE THREE RAIL TRAIN. THE ENGINES SEEM TO MAKE A VERY LOUD NOISE AS THEY GO OVER THE BALLASTED SECTION, BUT RUN FAILY QUIET OVER THE REGUALR PAINTED, UNBALLASTED TRACK. iS THIS A NORMAL THING, SHOULD I EXPECT THIS, OR HAVE I SCREWED UP YET AGAIN???
I would guess that you used diluted white glue to attach your ballast to the layout, this dries hard and amplifies the noise of the rolling stock passing over it, no getting out of it I am afraid, using matte medium (diluted) can lessen this effect as it dries with a more rubbery finsh, the only problem with this is that it is not water soluble and thus harder to remove if you decide to change the track plan in the future. Hope this helps, or atleast puts your mind at rest that you are in the same boat as the rest of us.
Have fun & be safe,
Karl.
PS: friendly note… typing all in caps is considered as yelling to most folks
I think cork (or Woodland Scenics’s black foam) roadbed might have helped a bit to minimize this problem, which as Karl says is pretty much a natural phenomenon of using hard glue. Even railroads with minimal ballast usually have a slightly built up right of way for drainage purposes – that is what roadbed is supposed to mimic, not ballast per se.
I suspect, but do not know, that the blue foam itself might act a bit like a sounding board. Time for some troubleshooting. I suggest an experiment or two. Run the train so that it makes the noise. What can you do to lessen it? Does placing the flat of your hand on the underside of the layout and pushing up a little lessen the noise? If so that suggests that it is insufficiently supported and that the blue foam is acting, more or less, like a guitar body, actually amplifying the sound.
Does reaching over and pulling the edges together lessen the sound? That would suggest that there might be an overall looseness to the construction – tighten it up
Does pushing down lightly on the layout help at all? Maybe rubber gaskets or washers where the frame meets the legs might help.
These are all wild guesses on my part. But sound is vibration and moving air and there may be nothing you can do about the glued ballast but if the foam can be made to vibrate less it might help.
Dave Nelson
This is one thing I never understand. What is the thing with quiet ballast? Real trains are loud noisy things. I love it when the trains go on to the hard ballasted section and make train noises as they move through the scene. But then that is just me.
I have found that the foam amplifies the sound significantly. I have a section where the blue foam is glued to plywood and a section where is it accross wooden cross members with open sections. The noise is vastly greater in the section without plywood.
Foam would only dampen the sound, if anything. I noticed the same noise difference between ballasted and unballasted track. I used plain wood glue (on Woodland scenics cork on plywood). Karl’s tip for a more rubbery glue is very valuable, because I don’t think my downstairs neighbours like the sound as much as I do!
In response to ukguy’s comment that matte medium is hard to remove for changes I found that good old alcohol works very well. I had to remove 6 Shinohara turnouts in a yard to make them DCC friendly. Use eye dropper to soak the area and pallet knife to slip under the ties.
Also I found that duluted white glue tends to darken the ballest - light gray turned to dark gray.
rkswp
Actually, quite the opposite. Foam acts as a resonance surface, much like the taught animal skins on a drum. Add a piece of plywood in lieu of the skin, and you’ve got one quiet drum!
One of the major (and only) disadvantages of building a foam-based layout IS the additional noise created by the resonance of the foam, but there are several things you can do to reduce that effect.
Possibly the best thing you can do is to use “rubbery” adhesives, or anything with a little flex. I use latex caulk to attach my track to the foam (or cork), but I’ve found that 100% silicone caulk actually works better as a sound deadener. So if it’s not track or the scenery base, I use silicone caulk to glue stuff down. Whatever you do DON’T use wood glue at all; it’s VERY rigid, and only acts as a noise amplifier. Elmer’s makes a “rubbery” white glue that I suspect is part matte medium. I haven’t been able to find it in a while, so I use white glue for most of my scenery needs, as I find the hold of matte medium to be unsatisfactory.
Backing the foam with even 1/8" thick plywood does wonders for deadening the sound amplification. My last layout used both 1/4" Lauan plywood and 1/4" pine plywood as a base. The sections using pine were dead quiet.
Finally, look to your trains themselves. You can do three things to reduce the roadbed noise: use modern, can-motored engines, use sound decoders in engines, and run trains slower.