I have a piece of plywood framed out with HO Kato unitrack sitting on top not attached. Anyone have any pointers for the best way to attach this so trains run quietly? I have experience screwing Z scale unitrack directly to plywood and I felt it made the trains reverberate a lot more than when the track was not attached. How much would glueing some blue board foam insulation to the top of the plywood help?
Thanks. I've done cork in Z scale, but if I screw in the track through the cork, it seemed to make the same noise because it would reverberate through the screws. I'm guessing for quietness, I need to glue the track to the cork or foam, using some Elmer's?
You might try using Liquid nails for projects. It’s water based and will not attack foam. Like Regular Liquid Nails does.
I like using silicone caulking because it remains flexible when dry. I'm not sure how it would work with Unitrack. I spread it in a very thin layer and place my track on top. I try not to press it in to the caulking, I just place it on top. Its tacky enough to hold track until it drys. Also if i use it on foam I can just rub it with my fingers to remove the silicone caulking once its dry. This works for wood too if the wood is nice and smooth. If the wood has more imperfections you might have to use an eraser or piece of rubber to remove the caulk. Glue and paint wont stick to silicone, so if ballasting over it you need to build up a shell that is adhered to itself and anything else that isnt covered by the silicon. Remember to spread it thin, .0625, 1/16". Also glue it piece by piece, when it is spread so thin it dries pretty fast.
DAP Alex Plus with Silicone. Cheap like borscht, and it works. However, I have experience in the past six years with two kinds of the product, the stuff that dries clear and the stuff that dries white. Both go on looking like bathtub caulk, but the 'clear' stuff eventually gets close...somewhat yellow, but mostly clear. You want that. NOT THE WHITE. The white drying stuff had half the stickiness and rubbery qualities which is what you want to keep everything quiet. So, the same product to place the cork into position, then the same to adhere the track elements. The idea, both times, is to just make a thin film. Don't bead it, don't goop it...use a spatula to spread it skinny. Weight or use track nails to keep the cork in place, then place the tracks and use soda and soup tins on their sides atop the rails to keep them weighed and in place. Takes about two hours to dry enough that you can remove fasteners/weight and run trains.
Thanks for the tips, everyone. Has anyone used Elmer's to glue down unitrack? Are there any advantages or disadvantages?
I did a module with cork and glued the track to it with wood glue. It has a noticably different sound. I think the hard part with Unitrak is that there is very little surface contact area. It is just the ballast easement on the sides that touches the ground. I did a T-Trak module with unitrack and glued the track down with foam glue. It stuck pretty solid, but I am still a little skeptical of long-term strength.
Latex caulk is easily removed if you decide to change things later. I found liquid nails was too good for the task. Still can't get the old cork up off my old door panel.
Just to be clear here. It's not the plywood that's making the noise. In fact the quietest way to lay track would be track directly on plywood. The track noise is caused by the air gap underneath the plastic roadbed. It is effectively a chamber that amplifies the sound. The denser the material, the less noise it will make. Blue/Pink Foam will actually lead to noisier layouts, because it is not dense, so it again, amplifies the noise. Direct on the plywood or on cork are the best options. As for unitrack. It would not be cheap and you pretty much wouldn't be able to pull it up, but your best bet for noise reduction is to probably lay it using some form of caulk and just fill the entire cavity with the stuff so there's no open space.
Good point about insulation foam being a fairly good amplifier. I'm building my layout on insulation foam, but I'm using corked, glued- down traditional track to cut down on the noise. I'd differ slightly on two points. 1-Even without an air chamber, a soundboard (a piece of plywood in this case) can still cause the air to vibrate quite a lot. Consider the musical saw as an example. Thicker plywood will vibrate less, but plywood (especially thinner plywood) will vibrate like the top of a guitar and cause the air around it to vibrate. As a practical test, tap the plywood with a hammer and take a listen. 2) Filling the space under the unitrack with caulk would cut down on the vibrations a bit (plastic track roadbed also vibrates easily) but I wouldn't recommend it as it would be darn near impossible to reuse the track later which is the primary beneift of unitrack. One other factor worth considering, what surface is the table being built on? If the benchwork is resting on a wood floor, consider rubber feet and/or a rug to keep the entire floor from becoming a sounding board.
I run this track and find it bullet-proof and quiet. Silicone is the absolute best way I have found, the key being it remains flexible. PVA / white glue was terrible after it hardened. My track is on cork (either roadbed or sheet depending on location, yards and street line on sheet, mainline on roadbed), below that is blue extruded foam board and finally 1/4" Baltic birch. I do not get the "foam drum" that others have experienced, which I attribute to the varying material densities and the flexible adhesive used. You will run into situations, particularly in HO scale, where Unitrack simply does not have the geometry you need - fitting in code 83 flex and / or switches is easily done when you get to that point. Enjoy your railroad! Bill
Silicone is probably your best bet. To go back to the musical instrument analogy, if a tiny little piece of rubber ( a "mute") stuck on the bridge of a violin can notably mute the tone, then adhering the edges of your track with silicone rubber should pretty well deaden the sound.
I agree. Direct contact between the plastic fake ballast and any surface will transmit vibrations, including those that are audible, to the surface supporting the plastic ballast, and will be noisy. That is why a thin barrier of spread caulking does a good job of quieting the track noise. In fact, dual densities that are different, say cork on plywood, or plywood strips for roadbed that are soft-glued or merely set upon drywall as a base for a layout, would be very quiet indeed. Our problem is that we harden our poured ballast grains, or we use hardening glues like yellow or white glues, to adhere the track elements directly to something...anything...cork, foam, drywall, plywood....and that makes it noisy once again because the grains of glued sand touch the plywood base, spilling down the sides of the cork or other types of roadbed. My most quiet track sections, on every layout, without exception, and glaringly so compared to the tracks on either side, are....wait for it....suspended. Over bridges, in fact. It's amazing. No ballast. Only a thin caulk layer to adhere the tracks securely to the stringers there on the bridge structure to support the tracks.
Ah! The ballast and glue is not something I had considered. It does make a lot of sense then to use an acrylic product instead of a more brittle glue. I wonder also if that's a doubly good reason to lay down a thick layer (or more) of latex paint on top of the foam before doing any scenery work?
Many swear by latex over foam, I have not used the technique as I am in the infant stages of scenery. What I have right now is sheet cork over the foam, then a Baltic birch sheet below that. I plan to continue along that line as I move out to more open spaces and may very well latex over foam at that point using cork only under the attached roadbed. There are a couple of long discussions over on https://model-railroad-hobbyist.com/node/15325 and https://model-railroad-hobbyist.com/node/15420 , the author I believe retired as a sound engineer, so he rigged numerous tests up and measured decibels at various points / conditions. But, there are several that have now decided their RR is too quiet, and have taken to cutting gaps at scale distances to bring the clickety-clack back! Of course the most important part of all this is no derailments and smooth trouble-free ops, and having fun! Bill
