Trains.com

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Question on roadbeds and ballast

2134 views
13 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    August 2008
  • 18 posts
Question on roadbeds and ballast
Posted by UK78ALUM on Thursday, October 30, 2008 5:30 AM

 Just finished watching part of a video sent to me by MR.  It has the table surface made from birch plywood topped with construction foam sheets.   That being the case, I have some questions:

1.  One of the stated purposes of the cork roadbed is "quiet operation".   But do you use it on top of the foam as well?  Is this overkill?

2.  Is there a covering (material, paint,etc.) of any kind put on top of the foam sheets first?

3.  If you do, in fact,  use the cork roadbed, I would assume that it is glued in place on the foam.  So, what type of glue is best?

4.  If I'm going to go as stated above, then how is the track itself attached?  More glue?  Nails or brads?  I am thinking that any type of nail or brad is now going only into cork and/or foam (as opposed to into the plywood).  Is that enough to hold it?

5.  Finally, I'd appreciate all suggestions on ballast.  Material to use, method of application, etc.   This is something I have never done.

Thanks everyone!

 

Dave Lexington KY
  • Member since
    January 2008
  • From: Central Georgia
  • 921 posts
Posted by Johnnny_reb on Thursday, October 30, 2008 6:15 AM

When I built my last layout I used “Latex caulk” to glue the foam board down to the plywood and craft matte medium to glue the cork roadbed and track down to the foam. I tried using white glue and found that it dried to hard and transmitted sound too good. It made the plywood and foam board act like a drumhead. As for ballasting I had to move and dismantled my layout before I got that far. But I will say that the matte medium did make taking up the track easier then the latex caulking did on the foam board. I used too much caulking. When I laid the cork and track I used "T" pins to hold it in place while the matte medium dried then removed the pins once dried.

Johnnny_reb Once a word is spoken it can not be unspoken!

My Train Page   My Photobucket Page   My YouTube Channel

  • Member since
    December 2004
  • From: Bedford, MA, USA
  • 21,424 posts
Posted by MisterBeasley on Thursday, October 30, 2008 6:34 AM

My layout uses 2-inch construction foam on a wood frame benchwork.  There is no plywood layer, nor do I think one is necessary.  The foam itself is very stiff.  Foam will not support people climbing on top of it, however, so if you must do that during construction, then plywood might be a good idea.  Once you have foam on top of the plywood, however, don't climb on that.  Your weight (well, my weight, anyway) would easily crush the foam.

I used latex caulk to attach the foam to the benchwork.  After 3 years, no problems.

I use Woodland Scenics foam roadbed, too.  This is a different material than cork roadbed.  Most of my roadbed is held on with latex caulk, although I've put some down with white glue.  I don't think I can tell the difference in sound level.  The foam roadbed is softer, though, and probably is better at reducing noise than cork.

The real purpose of roadbed is to elevate the track above grade level in a prototypical fashion.  It isn't there for cushioning or noise reduction.  It's a scenic thing.  Many modellers use no roadbed in yards or on industrial sidings, for example, and they instead just lay the track directly on their base foam or plywood.  (Yes, they do need a short "ramp" section to change elevation a bit.)  Again, that's the way the real railroads do it.

I glue my track down, too.  Once again, I've mostly used latex caulk for that, and sometimes I use white glue.  Both seem to work about the same.  Latex caulk, by the way, comes in a tube and is applied with a caulking gun.  The only problem I have with the stuff is shelf life.  Once I open a tube, it starts to harden, even in the tube, and after a couple of months the tube is ready for the trash.  When you're starting out and building benchwork, gluing on foam and laying lots of track, that's not much of a problem.  Lowe's has the stuff for $3 a tube, anyway.  (I use Liquid Nails for Projects.)  But, once your layout has progressed and you only lay a few feet of track, maybe for a new siding, every couple of months, then it's just more convenient to go with white glue.

I won't get into ballasting details, but it's usually applied with a thinned-down white glue.  This will harden up, and you may find it transmits sound better than unballasted track.  If that bothers you, well, get some sound engines, and put metal wheels on all your rolling stock.  Between the chuffing, bell-ringing and enhanced clickity-clack of the wheels, you'll never notice the small stuff.

It takes an iron man to play with a toy iron horse. 

  • Member since
    May 2002
  • From: Just outside Atlanta
  • 422 posts
Posted by jockellis on Thursday, October 30, 2008 9:15 AM
If you use cork, remember to round off the top outer edges of the cork before you lay your track. Very important! I don't know whether the foam is rounded off or whether you have to do that. I used Woodland Scenic's Hob-e-Tac cement to stick the gravel to the outer bank and the rounded off corner at the top of the cork. For the ballast between the rails and ties, I diluted white glue about 7 parts water to one part glue. I poured the gravel between the rails and used a long, soft bristled brush which had almost no spring to brush the ballast between the ties. This brush is just the opposite of what Dave Frary advises in his books but it was the only way I could get the individual "rocks" off the top of the ties. I then took my water and glue mixture and used an eye dropper to put a drop between ties. You could see the capillary action spread the glue to the extremities of the box created by rails and ties. This is again just the opposite of Frary's method. I tried his and sprayed the track. When the water mist hit the ballast, it caused it to bunch up rather than lie flat. I then poured my ballast onto the ties outside the rails and worked it with the brush until it reached the ballast previously tacked to the beveled edge of the cork. I used the eyedropper method to attach this ballast, too. My method, admittedly, takes a while and I haven't done the whole layout yet but it is a most relaxing part of the process because there is no guesswork to whether you are doing it right and it doesn't have to be done before something hardens. The ballast stays down unless I touch it with a finger. Any such pressure will break the glue bond. But we don't usually stick our fingers on the track so that has been of no concern. One other thing. I've noticed that nearly everyone tends to take methods and change them slightly to fit their needs. And it works! The nice thing about model railroads is that in most cases, the track, trains, buildings and scenery come together to perform magic and, like the velveteen rabbit, become real.

Jock Ellis Cumming, GA US of A Georgia Association of Railroad Passengers

  • Member since
    July 2004
  • From: Carmichael, CA
  • 8,055 posts
Posted by twhite on Thursday, October 30, 2008 11:12 AM

Like Mr. Beasely, my HO-scale Yuba River Sub garage layout is built with 2" extruded foam on a wood frame construction.  Everything he says about the foam is true, however I cross-braced under the foam about every 12" to ensure stability.  My roadbed is WS foam on WS risers for my grades, and I laid everything down with latex caulk and in some portions, Elmer's Carpenter Glue (only because I'd run out of caulk and I was in a hurry, LOL!).  Both have worked for me very well so far in the 7-plus life of the railroad. 

For the most part my trackage is laid down with latex caulk, and I used long WS scenery pins to hold the track to the proper radius while the caulk dried.  I do have one portion of the layout--Yuba Pass--where instead of using flex-track, I used EZ wide radius (34") track to ensure very even radii on curves on trackage that overlook a sheer six actual foot drop to the concrete garage floor.  The EZ track affixed to the WS roadbed very easily by using a bead of caulk along each side of the EZ track roadbed. 

For ballast, I've used a mixture of medium and fine WS ballast in various shades to represent both main and yard trackage, and I've used the old method of thinned white glue and 'wet' water (two drops of liquid detergent in a spray-bottle of tap water), and it's worked fine for me.  Remember to go over the inside of the rails lightly with a small screwdriver after the ballast dries to get any specks off that might hinder your running, and vacuum up the residue. 

I like the foam base, it's lightweight and very sturdy.  And it does tend to cut down the 'rumbling' noise of the trains running to a degree.  Of course, I don't mind the 'rumbling' very much, anyway.  Ever stand next to a real train running down a heavily ballasted mainline?  Now THERE'S some 'rumbling' for you.Tongue   

Tom Smile

  • Member since
    August 2005
  • From: S.E. Adirondacks, NY
  • 3,246 posts
Posted by modelmaker51 on Thursday, October 30, 2008 4:57 PM

jockellis
If you use cork, remember to round off the top outer edges of the cork before you lay your track. Very important! I don't know whether the foam is rounded off or whether you have to do that. I used Woodland Scenic's Hob-e-Tac cement to stick the gravel to the outer bank and the rounded off corner at the top of the cork. For the ballast between the rails and ties, I diluted white glue about 7 parts water to one part glue. I poured the gravel between the rails and used a long, soft bristled brush which had almost no spring to brush the ballast between the ties. This brush is just the opposite of what Dave Frary advises in his books but it was the only way I could get the individual "rocks" off the top of the ties. I then took my water and glue mixture and used an eye dropper to put a drop between ties. You could see the capillary action spread the glue to the extremities of the box created by rails and ties. This is again just the opposite of Frary's method. I tried his and sprayed the track. When the water mist hit the ballast, it caused it to bunch up rather than lie flat. I then poured my ballast onto the ties outside the rails and worked it with the brush until it reached the ballast previously tacked to the beveled edge of the cork. I used the eyedropper method to attach this ballast, too. My method, admittedly, takes a while and I haven't done the whole layout yet but it is a most relaxing part of the process because there is no guesswork to whether you are doing it right and it doesn't have to be done before something hardens. The ballast stays down unless I touch it with a finger. Any such pressure will break the glue bond. But we don't usually stick our fingers on the track so that has been of no concern. One other thing. I've noticed that nearly everyone tends to take methods and change them slightly to fit their needs. And it works! The nice thing about model railroads is that in most cases, the track, trains, buildings and scenery come together to perform magic and, like the velveteen rabbit, become real.

 

From your description, it's sounds like you're not using any kind of "wetting" agent. When  you drip on your glue without a wetting agent, the glue only partially penetrates the ballast, creating a "crust" and thus when touched with a finger can crumble. A wetting agent cuts the surface tension and allows the glue to be fully absorbed. You can pre-wet the ballast with a spray bottle of water and 4 or 5 drops of dish detergent (the preferred way) or add a few drops of detergent to your glue mix, which btw, is a bit on the thin side, also contributing to the crusting, 50/50 is better. Another way is to substitute 10% of the glue mix with isopropl alcohol.

Jay 

C-415 Build: https://imageshack.com/a/tShC/1 

Other builds: https://imageshack.com/my/albums 

  • Member since
    August 2004
  • From: Virginia Beach
  • 2,150 posts
Posted by tangerine-jack on Thursday, October 30, 2008 5:41 PM

I gave up trying to make roadbed quiet about 20 years ago.  It's all crap, the train will make noise no matter what you do so why knock yourself out by trying to square the circle?  As was stated before, real trains make noise, and lots of it, so get yourself an inexpensive sound system and listen to that, not your roadbed.  The closest thing I've ever experienced to a "quiet" train was on the AMTRAK electric lines up north- but even those make sound (and sound very similar to a model train running on noisy roadbed).

The Dixie D Short Line "Lux Lucet In Tenebris Nihil Igitur Mors Est Ad Nos 2001"

  • Member since
    November 2004
  • From: Chateau-Richer, QC (CANADA)
  • 833 posts
Posted by chateauricher on Friday, October 31, 2008 3:02 AM

UK78ALUM

 Just finished watching part of a video sent to me by MR.  It has the table surface made from birch plywood topped with construction foam sheets.   That being the case, I have some questions:

1.  One of the stated purposes of the cork roadbed is "quiet operation".   But do you use it on top of the foam as well?  Is this overkill?

Overkill ?  No; but you won't find a more cost-effective, easy-to-use, easy-to-find product to create the profile of a roadbed.

NOTE :  If you do use foam sheets, be sure it is the extruded foam (pink or blue) and not the expanded foam (white).  You'll find the extruded foam far easier and less messy to work with than expanded foam.

2.  Is there a covering (material, paint,etc.) of any kind put on top of the foam sheets first?

You can use latex paint.  In fact, most people paint the foam a brown-ish colour before laying any track.  This provides for a good base-colour for whatever ground cover you plan to use.

3.  If you do, in fact,  use the cork roadbed, I would assume that it is glued in place on the foam.  So, what type of glue is best?

Since foam won't hold nails, you have to use an adhesive.  An inexpensive easy-to-apply adhesive that many people have had success with is latex caulk.  Spread a very thin layer along the path your tracks will take, place the roadbed, then use long sewing pins and weights (eg:  canned vegetables) to hold the roadbed in place as the caulk sets (at least overnight).  Latex caulk comes in many colours.  I would suggest using clear (goes on white and dries clear).  Be sure to use a paintable caulk so that you can paint over any that might squish out from under the roadbed.

4.  If I'm going to go as stated above, then how is the track itself attached?  More glue?  Nails or brads?  I am thinking that any type of nail or brad is now going only into cork and/or foam (as opposed to into the plywood).  Is that enough to hold it?

Just use the same caulk you used to lay the roadbed down (see my anser to question 3).  In this case, you can use clear caulk, or caulk of a colour close to your ballast colour.  Again, use a thin layer, and long sewing pins and weights to hold the track in place (especially on curves).  Take care to avoid getting any caulk on your turnouts or you'll find they will get gummed up and no longer work properly.

5.  Finally, I'd appreciate all suggestions on ballast.  Material to use, method of application, etc.   This is something I have never done.

Woodland Scenics is just one company that offers ballast in a wide variety of colours and sizes.  You may find that you'll prefer a mix of colours to get the effect you desire.

As for ballasting techniques, you can find out more in the November 2008 copy of Model Railroader magazine.

Timothy The gods must love stupid people; they sure made a lot. The only insanity I suffer from is yours. Some people are so stupid, only surgery can get an idea in their heads.
IslandView Railroads On our trains, the service is surpassed only by the view !
  • Member since
    January 2004
  • From: Canada, eh?
  • 13,375 posts
Posted by doctorwayne on Friday, October 31, 2008 9:51 AM

I've used the Woodland Scenics foam roadbed, atop extruded foam sheets, on a friend's layout, and we used WS cement to fasten it in place.  We then used regular Atlas track nails to hold the flex track in place, which seems sufficient for now.  Ballasting should provide a more solid method, when we get around to it.  One of the drawbacks of the foam roadbed is that it's difficult to transition down to yard areas, or, as on his layout, to the turntable, which was already in place.  We ended up using a length of cork roadbed there, which was easy to sand down to make a gradual slope.

On my own layout, I didn't use foam, as mine is 3/4" plywood roadbed atop open grid benchwork.  The flex track is on cork roadbed in most places, or directly on the plywood, and held in place with Atlas track nails.  I ballasted the track using the following method, which is cheap, easy, and effective.  After ballasting, the track nails can be removed, although I didn't bother.

To ballast your track, I find that a small paper cup (such as those kitchen or bathroom Dixie cups) gives you great control over where the ballast goes. I usually move the cup along the centre of the track, tapping it as I go, to keep the ballast flowing. Less than you need is better than too much, although a soft 1/2" brush is useful for pushing around the excess or levelling what's in place. Then go back and do both roadbed shoulders in turn. Use the brush to level and re-arrange things as required, making sure to keep the ballast away from the throwbar area and the flangeways of the guardrails. To remove stray ballast from the tie tops, lightly grasp the metal ferrule of the brush between the thumb and forefingers of one hand, laying the handle across the rail tops, then, as you move the brush along the tracks, lightly and rapidly tap the brush handle with the fingers of your free hand. The stray ballast will "magically" bounce off the ties and into place between them.
If you're also ballasting turnouts, make sure to keep the level of the ballast below the tops of the ties, and don't place any ballast between the ties surrounding the throw bar. To avoid gluing the points to the ties, place two drops of plastic-compatible oil atop each tie over which the point rails move, one next to each point rail, then flip the points back-and-forth several times to spread the oil. Parking the points in mid-throw will also help to ensure that they don't get glued to the stock rails, either.
You can mist the contoured ballast using either water and alcohol, or water with a few drops of dish detergent added. Either should work. Use a sprayer that will allow you to spray a fine mist. To avoid having the force of the spray dislodge loose ballast all over the landscape, aim the first few spritzes upward, letting the droplets fall like rain. Once the surface has been wetted, you'll be able to spray it directly. Make sure to thoroughly wet the ballast right down to the base. Not doing so is probably the main reason that many people have trouble getting a decent-looking and durable ballasting job. To apply the glue/water mixture (white glue works just as well as matte medium and is way cheaper, especially if you buy it by the gallon. Those who claim that white glue dries shiny are not using sufficient wetting agent. The proportions should be about 50/50 water/glue, although a little heavier on the water will still work well).  To apply the glue mixture, don't ruin a perfectly good spray bottle (and while doing so cover your rails and anything else nearby in glue, too):  instead, use a dropper. An eyedropper will work, but a plastic squeeze bottle with a small nozzle will be much faster. Simply move along the track, as quickly as necessary, allowing the glue mixture to drip onto the ballast (or ties - you won't see it once it dries). You should be able to see it being drawn into the ballast, due to the wetting agent. I usually do the area between the rails first, then the sides in turn. The glue mixture will spread throughout the ballast and down to the roadbed, so make sure to apply enough to allow this to occur. The result will be ballast bonded solidly in place, yet with the appearance of loose, individual pieces.

Where I have scenic areas adjacent to, but below the level of the track, I also apply the basic ground cover, which also helps to soak up the excess glue that spreads out from the ballast line.  If you're applying ballast (or ground cover) to steeply sloped areas, use a suitable-width brush to apply undiluted white glue to the slope before applying the ballast or ground foam, which will help to hold everything in place while you apply the wetting agent and the dilute white glue (these steps help to bond the top layers of material to those in contact with the unthinned glue, and also help to draw that glue up into the top layers).  In the photos below, the ballast, sub-ballast, and rock fill, along with the trackside weeds, was all applied and secured in the same step.
I still have a second level of the layout to construct, and may use extruded foam atop open grid, framework, although my only reason for doing so would be to enable me to cut the roadbed and sub-roadbed profiles with a hot wire cutter, and at the same time include the trackside drainage ditches.  In my opinion, using foam over plywood before laying the tracks only adds another level of complication to what is otherwise a very simple task.  Using foam, without the plywood, can be an effective way to save weight for portable layouts or modules, and it also offers a viable way of adding scenic contours to a layout, but in most cases there's no need to put it under the track, unless, of course, you wish to add scenic contours below track level.

It's also possible to convey the impression of a raised roadbed by using different scenic materials, as in the scene below, which is all (except the "water" area) directly atop plywood, with no roadbed:

Some of the fill here is almost an inch deep, as the scenic landforms (plaster over screen) turned out to give not quite the results that I had envisioned - I simply kept adding material until the contours looked right to me:

The low area to the left of the track in the picture below was a "lake" of dilute white glue for a couple of days after ballasting here.  I sprinkled some ground foam over the area, which will eventually become an orchard, to soak up the excess:

In the photo below, the track with the lighter ballast is atop cork, while the rest is directly atop the plywood: 

Here's the same area as seen from the air.  Much of the area away from the tracks is unfinished, but the ground cover alongside the tracks was done at the same time as the ballasting:

Here's the same area, looking in the opposite direction, as seen from track level (those wooden "clouds" in the background are supports for the as-yet-to-be-built second level of the layout):

Wayne

  • Member since
    February 2005
  • From: Vancouver Island, BC
  • 23,330 posts
Posted by selector on Friday, October 31, 2008 11:55 AM

I used EZ-Track caulked directly to 1/5" extruded Dow foam on my first layout.  It was noisy after I ballasted the plastic ballast base that comes on the EZ-Track.  Currently, I use both cork and vinyl underlay as roadbed, and they are both very quiet.  Out on my mains, I usee spline roadbed, and merely used caulk to adhere the flex track sections to the splines.  They are dead quiet.

The secret to quiet tracks, in my opinion, is to use at least two different layers of material of different densities.  I learned this in my other hobby, Astronomy, when trying to dampen out vibrations in my telescope.  After touching the scope for any reason, it would vibrate, osscilate really, for several long seconds as viewed in the eyepiece...whatever I was viewing would wave back and forth for up to 6 or seven seconds.  Using specially designed foot pads to keep the tripod off the ground or a deck made a huge difference.  So, too, with a thin layer of caulk and cork or MDF or vinyl between your main bench and the ties.  Dual densities do the magic on my layout, and it is gratifyingly quiet.

  • Member since
    May 2002
  • From: Just outside Atlanta
  • 422 posts
Posted by jockellis on Wednesday, November 5, 2008 9:39 AM
Jay, Why would you stick your finger into the ballast after you've put it down. I asked because my ballast stayed perfectly for over three years until a couple of weeks ago when I stuck my finger between the ties and, by golly, you're right. It did come up. But the stupidity was my sticking my finger on the track. Reminds me of the days when Minolta sold the SRT 101. Everyone I knew that had one had to take it to the repair shop because they had stuck their fingers in the shutter while it was on bulb then let it close on their fingers. Of course it broke. But the problem was with the photographer, not the camera. My conclusion was that stupid people bought Minoltas. I must be stupid for having stuck my finger into the ballast, too!

Jock Ellis Cumming, GA US of A Georgia Association of Railroad Passengers

  • Member since
    April 2006
  • From: THE FAR, FAR REACHES OF THE WILD, WILD WEST!
  • 3,672 posts
Posted by R. T. POTEET on Wednesday, November 5, 2008 10:05 AM

I am a "hardshell" man so I can't address the issue of foam.

I "overkill" with a sandwich of 3/8" plywood, 1/2" Homasote®, and cork roadbed. On my last layout I tried laying some of my ballast using water based glue on the off chance that it might allow me to salvage my flex track when and if I decided to/had to discard it. I did the latter a year ago; I was able to recover my flex track but it was a chore. I had not tried it with my handlaid switches but now that I know it will work I should be able to recover my frogs on any future layouts.

From the far, far reaches of the wild, wild west I am: rtpoteet

  • Member since
    March 2008
  • From: Atlantic, IA 50022
  • 42 posts
Posted by durango on Wednesday, November 5, 2008 11:34 AM

You asked about what material to use for ballast--ground walnut shells.  Years ago , I stumbled onto the 'home' of a rather well known southern calif company who blends and markets the ballast.  I had always envisioned this large factory setting, but in fact, it was set up in a shack in their back yard.

They had 2 or 3 small (3 cubic foot) concrete mixers and would put the ground shells into the mixer and dribble latex house paint into the shells as it turned.  I believe that they just let it turn until the mix was dry.  I was able to acquire aboout a gallon of over spill from the floor and still have most of it, although its a pain to sift out the debris.

Where to get the shells?  One of the uses is for tumbling cartridge cases to clean them before reloading.  Most gunshops who have a decent reloading section should have it, but it may be a little course for your scale.  I got lucky at the last gunshow and got a gallon of ultra, ultra fine for about $4.00.  You could also try a sandblasting shop--if they still use it what with all the new technology.

If anybody is interested, I'm going to the show over Thanksgiving weekend and should be able to buy more or get the name of the source(somewhere in Iowa).  Next trick is what to use for a mixer??--Steve

  • Member since
    January 2004
  • From: Canada, eh?
  • 13,375 posts
Posted by doctorwayne on Wednesday, November 5, 2008 11:40 AM

jockellis
Jay, Why would you stick your finger into the ballast after you've put it down. I asked because my ballast stayed perfectly for over three years until a couple of weeks ago when I stuck my finger between the ties and, by golly, you're right. It did come up. But the stupidity was my sticking my finger on the track. Reminds me of the days when Minolta sold the SRT 101. Everyone I knew that had one had to take it to the repair shop because they had stuck their fingers in the shutter while it was on bulb then let it close on their fingers. Of course it broke. But the problem was with the photographer, not the camera. My conclusion was that stupid people bought Minoltas. I must be stupid for having stuck my finger into the ballast, too!

 

Using the methods which I described above, you should be able to use a shop vac to vacuum the track, and not be concerned about lifting the ballast.  Incidently, if you accidently spill too much ballast (or ground foam) while doing scenery work, you can easily recover it by using a shop vac or any vacuum with a hose attachment:  simply remove the nozzle or tool attachment on the end, cover the rear opening of it with a piece of old pantyhose or nylon stocking, the re-attach it to the hose and vacuum.  The nylon will prevent the material from being drawn into the cannister, and it can be dumped onto a sheet of newspaper, then returned to the original container, for re-use.

Wayne

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Users Online

There are no community member online

Search the Community

ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT
Model Railroader Newsletter See all
Sign up for our FREE e-newsletter and get model railroad news in your inbox!