Vacuuming

The only issue I would see is that occasionally I like to run a small vacuum over the railroad especially down the tracks to pick up any loose dirt, dust, stuff, etc that might accumulate. Can't do that if the ballast isn't glued.

" NOT glued it down? "

I never glued the ballast down on my O scale layouts. The first one I used gray mortar mix for ballast and it sorta surface  hardened from moisture in the air, the last one used fine gravel and dirt mixture and I just brushed it out dry and left it there. O scale  is big enough that loose ballast is not a problem but HO ballast might be too fine to stay put during things like sneezing , blowing dust off models, etc?  With O scale ballast  it was easy to just push it back in place if it got disturbed but in smaller scales it might not be so easy? I plan to glue the ballast on my N layout since the amount of gluing required will be tiny compared to the O scale layout ......DaveBranum

Rick, on a previous layout

Rick,

on a previous layout (edit : HO scale) I came to the same idea. Tested it on a segment : Sound level - less noisy than the rest.

My setup was track on cork with plywood base cut to the width of the roadbed.

But when it comes to clean this section of track - horrible.

Ever tried to weather unglued ballast ?

To sum it up, finally I glued this section as the rest of the layout.

depends

in N scale inside, I glue it down, Fn3 outside, well, it needs to drain

Although I have never tried

Although I have never tried unglued ballast, I can see a few possible problems.

Cleaning track, dusting and vacuuming would be difficult (as mentioned)  Derailments, although infrequent, can and do happen. A mess would be made of the shoulders of the roadbed contour and cause unwanted ballast in the grass and on other scenic elements.  Vibration from the trains rolling along may cause ballast to shift reducing the carefully manicured contour on the shoulders of the roadbed.

Of course, I have not tested any of this, and it may be perfectly OK to have unglued ballast. But one accidental mishap, could ruin a carefully detailed scene. 

Just my 2 cents.

Randy

Really Bad Idea

I've seen a few layouts with loose ballast, and recently visited one (the builder didn't want to change the color of his ballast materials with glue).  Invariably, loose ballast becomes a mess over time.   If you want your layout to be a mess too, go ahead.

It's not the trains running that cause the mess to happen.  You can't really clean the layout.  You must exercise extreme care at all times not to touch the ballast, so uncoupling, rerailing, and track maintenance will be a nuisance since with all those you end up potentially touching the ballast.  What happens when you accidentally bump the benchwork too hard?  What if you sneeze the wrong direction?  Use a ground throw? Run a car off the track? The ballast moves.  You will always be rearranging it.

Furthermore, loose ballast migrates into turnouts and plays havoc with their operation (it fouls points and gets into flangeways and around throwbars).  It creeps into other things affecting layout performance, such as attaching to locomotive lubrication and getting into the gears.

I frankly don't notice much difference in sound transmission on my layout from areas with ballast to those without.  Even if you are concerned about sound, is the slight reduction worth the tradeoffs for aesthetics, operation, and maintenance?  Would you rather have a marginally quieter layout that looks ratty and gives you neverending heartburn?

Nope, don't do it!

I think it's a really bad

I think it's a really bad idea.

... but then, I'm doing most of my modeling on modules right now...

From left field...

I think that if you used something like camper tape

under the roadbed, then glue down your ballast to the tape and bring your ground foam scenery up to the ballast, that you could probably isolate the noise transfer from the tracks to the bench work without needing to leave your ballast loose.

Noise?

I imagine if everyone waits a bit they will be be able to buy noise canceling equipment and just plug it in? I see it offered in some new cars now. My wife recently got a new honda Accord sport and it's very quiet, I don't know if it's the noise canceling feature or if it's just quiet to begin with. On a recent trip I was also also impressed to find it's 2.4L four can cruise at 80 MPH at about 2000 RPM still getting over 30 MPG.  We were laughing about how much cars have improved since our old Camaro days when we used over twice the cubic inches and almost three times the gas to cruise along at the same speed surrounded with more noise :> ) .....DaveBranum

There must be something...

I think loose ballast would wind up being quite a mess.  But you'd think there must be some kind of adhesive out there that's liquid enough to soak through the ballast but "rubbery" enough when cured to absorb sound.

Putty tape has been suggested as an alternative to Instant Roadbed if you want to go the smoosh-the-grains-into-the-roadbed route.   I've never tried either myself.

Spraying a thin cover of glue

Spraying a thin cover of glue over ballast just to hold the outside layer used to be the norm because of fiber ties used with flex track.   This was the accepted method well after plastic ties became available.  Shell glued ballast over cork is relatively quiet.  These days we need to have every ballast rock glued solid.  It is much louder.

Glue it and be done! All

Glue it and be done!

All this over engineering to overcome this noise issue...ha!!

"shell glued"

I once had the mix of glue wrong for ballasting and ended up with the shell effect. I soon discovered that the fragile shell simply chipped away when bumped. Not so good.

Yup

I've seen that too. It's almost as fragile and prone to a mess as unglued.

"almost as fragile and prone to a mess "

I think it's even worse than loose ballast as it breaks up into chunks which can't be re-arranged. The loose stuff just lays there and can be re-spread if it gets too messed up. Here's a yard track on my old O layout. I put down sculptamold between the tracks then tossed a bit of loose rock around the ties.It stayed that way with no problems till I decided to tear the layout down and build something else..DaveBranum  

Gluing Ballast

I have a buddy who doesnt glue his ballast down and he has trouble with the ballast getting into the web of the rails and causing derailments. Then also the loose ballast will work its way into the switches and we will have problems with thowing the switches and they wont lock into the diverging route. So with running H.O.,I would say Glue it down. You wont notice that much noise coming off the track. And if you have a problem with the noise that resinates off of the glued roadbed. Then you need a different hobby. Then with you glueing the ballast it wont magintize and get into your gears or motor of your engines.   Kevin

Glue it is - thanks all.

Poly it

We visited a layout up in VT and the owner puts on clinics on how he uses water base polyurethane diluted 50/50 with water. The ploy goes all the way throw the ballast and does not create the shell affect. Also is very durable, but one draw back it you can not re-wet it and remove the ballast like you can with white glue.

I am testing this with my modular for durability. 

loose ballast

Have you ever stood by the track and watched a train go by. Did you hear all the noise they make. Did you smell the smell. Did you look at the rail & ballast. Did you ask yourself What type of GLUE they use??? I can live with what little noise my model railroad give me and I still  love to run trains.