01 of 07
Laying Cork Roadbed - Reasons and Materials
Why Lay Cork Roadbed?
Adding roadbed material between the tracks and benchwork serves several important functions. Several varieties are available, but the most common are cork and foam products. Roadbed provides:
- Scenic base. The roadbed will be to provide a realistic shoulder for the ballast later, offering a realistic appearance for the track.
- Sound deadening. Roadbed, especially cork, helps quiet the rumble of the trains against the plywood.
- Track laying. Because you won't have to drive... spikes as hard into the cork, it is much easier to lay track on roadbed. And easier track laying leads to better track laying.
- Transition to Integrated Roadbed Track. If you've used track with a plastic roadbed attached, you can use roadbed to transition to conventional track.
The small cost and easy installation of cork make it a great value for the benefits provided.
Materials and Tools
The Rio Grande Narrow Gauge project layout is just the right size to show how to lay cork. The materials necessary for this project are shown here:
- Cork roadbed - the Rio Grande layout as designed will require 7 strips.
- Glue - white or wood glue will work.
- Nails - use track spikes.
- Simple hand tools - hammer, hobby/utility knife, rasp, straight edge.
All together, the materials for this layout will cost about $15. The project takes about 90 minutes to complete.Continue to 2 of 7 below.
02 of 07
Preparing Cork Roadbed
Most cork roadbed products come in 3-foot strips. The strips are slit down the middle at a 45-degree angle.
To begin, separate the two halves. The beveled edges will go to the outside and will help provide a prototypical slope profile for the ballast later. Note that one of the edges usually ends up very rough along the top. You'll want to clean this up after the cork is in place.
The 90-degree edges will line up against each other along the centerline of the track. Laying the cork in thin... parallel strips makes following curves much easier. It will also maintain a helpful centerline while laying track.
The cork strips are designed for standard gauge track. You can leave this width as is for narrow gauge layouts if you like, or you can proceed to the next step.Continue to 3 of 7 below.
03 of 07
Narrowing Cork Roadbed
If you choose to do so, you can narrow the commercial cork roadbed strips slightly to better match the 3-foot gauge of the tracks of this model railroad.
Lay a long straight edge along the cork on the inside (non-beveled) edge. Cut the cork with a sharp hobby or utility knife. Remove about 3/16" from one strip. Leave the other strip intact.
Precision is not terribly important here. In fact, you can skip the straight edge all together and just freehand the cuts, trying to stay parallel to the... edge.
You can vary the amount of cork removed as well. I settled on 3/16" as a happy medium, but you could go more or less depending on the equipment and railroad you're modeling. Keep two things in mind:
- Narrow gauge equipment generally tends to overhang the track a little more than conventional equipment, so be clearance conscious.
- Narrow gauge railroads were never known for meticulous rights-of-way. Even the largest systems like the DRG&W showed many variations in track quality.
Keep in mind that now that you have removed a portion on only one-half of the cork, by following the center line of the track on the subroadbed, your roadbed will be slightly off-center. This can be easily compensated for when laying track.
If you made any big mistakes and have gaps along the center line when you lay the cork, these can be easily filled with spackle later.Continue to 4 of 7 below.
04 of 07
Laying Cork Roadbed
Laying cork roadbed is an easy task if you've laid out the subroadbed with track center lines. Prior to laying cork, brush or vacuum away any sawdust or other dirt along the right-of-way to ensure an even track bed.
Start on one side of the center line. Lay a bead of white or wood glue to the left or right of the center line, about three feet in length. If you are building a temporary display, or if you expect to make changes, you do not have to glue. Compensate with more nails.
Where you... start on the platform really doesn't matter. For the Rio Grande layout, I chose to start at one end of the high bridge where I knew the track and roadbed will eventually be removed for the bridge itself.
Lay the cork along the center line and tack it in place with track nails. The nails are really only necessary to hold the cork into position until the glue dries. If you are gluing the roadbed, about five or six nails per strip should be more than enough, even on tight curves. Drive the nails completely into the cork so as not to interfere with the track later.
What do you do if you don't have a center line to follow? For easy easements or free hand curves, simply bend the cork strip into place at the ends. It will naturally assume the path of least resistance. The "S" curve seen here was laid in this fashion. Starting on the center lines of the curves at either end, the transition between came naturally.Continue to 5 of 7 below.
05 of 07
Laying Cork Roadbed
With the first strip in place, lay the second strip of cork in the same manner. Use the first strip as a guide. Stagger the ends to avoid kinks in curves.Continue to 6 of 7 below.
06 of 07
Cork Roadbed for Switches
Laying cork roadbed for switches is not much more difficult than any other track. Commercial cork products are available to match many common switch sections, but these are more expensive. If you have a hobby knife, you can make your own in minutes.
Continue to 7 of 7 below.
- Begin by placing the switch (turnout/points) on the layout. Trace the outline to provide a guide. If you've laid center lines, these will be a big help as well.
- Lay the cork along the stock (outside) rails first, starting from the point end of the... switch and working toward the frog. This is just like laying cork everywhere else except that the strips will be diverging.
- Double check the outer lines of the cork by placing the switch back into position.
- Next, fill in the center of the switch, working from the frog end toward the points. Use a hobby or utility knife to cut the cork pieces to fit.
- Cork doesn't always cut quite as crisply as you'd like. An exact fit is not necessary to support the track, but you may want to fill any larger holes with joint compound or a similar putty to save ballast later.
- Place a square of cork at the end of the throw bar for the switch stand or ground throw.
- If using a switch machine, you can drill easily through the cork along with the subroadbed. A template or jig makes locating these holes easier.
07 of 07
Finishing Cork Roadbed
To provide the best ballast profiles possible, some quick finishing work on the cork roadbed is necessary.
Cleaning the Edges
From the separation of the two strips, the edges of the cork roadbed may have rough edges. These will create a problem when trying to lay the ballast shoulder later. Use a rasp or a sure-form tool to clean up the edges and smooth the profile.
The cork will shape very easily and clean up to a nice smooth edge in seconds.
Any gaps between strips in the center or at... joints can be filled with drywall joint compound or a similar plaster or putty. Simply fill the gaps with a small putty knife and scrape smooth. This will prevent odd angles or pockets when pouring ballast later.
That's it! Your roadbed is ready for the track.