Laying Cork Roadbed


beiland

Well-Known Member
Laying Cork Roadbed

I am just about ready to start laying track and cork roadbed on sections of my main deck. Basically I will be using the standard 3/16” thick cork under all my mainlines surrounding the perimeter of the room.

I will have quite a number of turnouts on those mainlines leading off to secondary tracks feeding those mainlines. I want to use a lesser thickness cork on those feeder tracks,....in fact a sheet cork (available from Hobby Lobby) that is almost exactly half the thickness of the mainline cork.

I'm looking for advice about how to best handle these 'transition areas' where the cork roadbed makes a change in thickness. I've been worried about getting this correct for a long time. There was even a time when I considered not using any roadbed at all just to avoid this 'uneven' track base.
 
Example


On this side of my main deck I have a long track down along the wall (comes up from staging tracks via the helix) (track not shown in this photo, just its centerline penciled in) . The next 2 lines are the 2 mainlines (with crossovers). The inner one of those mainlines have turnouts that feed 2 ladders of turnouts for either end of the freight yard
image-20201105214950-1.jpeg

image-20201105215141-2.jpeg


Lets take a closer look at that turnout combination I circled above,...its a dbl-curved turnout on the mainline that is feeding a 3-way that serves the freight yard ladder and the diesel fueling area. The paper template laid over the cork roadbed would look like this
image-20201105215318-3.jpeg

image-20201105215355-4.jpeg

image-20201105215442-5.jpeg

That unevenness under the two would be very upsetting to me. I have always believed that any single turnout needs to be mounted on a firm level base.!

My solution for this would be to mount both of those turnouts on the thicker cork roadbed,...then attempt to grade down to the thinner roadbed off the 'square ends' of 3-way?....like this ??
image-20201105215536-6.jpeg


And what is the best way to make that transition in height?
 
Don't over think it. You fill the transition in with strips cut or sanded thinner than the mainline, sort of steps. The track will support itself at 2-3 inch intervals. So, mainline 2" gap, slightly thinner cork 2" gap slightly thinner cork, 2" gap, yard thickness cork.

Ballast covers your 'sin'.
 
I do not transition under any switches themselves, but rather start the transition about 2" past the joint. I insert strips of cardboard beneath the thinner cork to support the height reduction, but I don't worry too much because as Dennis posted, the track will support itself to a small extent and ballast will cover all sins.
In your case with multiple complex switchwork after the initial circled switch, I would consider dipping the main line down prior to that switch and then raising it back up after that. That would eliminate many transitions.
 
I would keep the thicker cork until you get past the turnout, then taper the thicker cork down to the height of the thinner cork by sanding. You could also do it the way santafewillie suggests...using thin strips of cardboard in successively thinner areas until the thinner cork comes up to the height of the thicker.
 
Usually the descent into a siding, which typically is at least 7" lower than the adjacent main rails, takes place after the frog and into the diverging route. You can actually bend the rails to dip a bit if you feel brave enough, but we're talking about 1-2 degrees at most, so use an easy and controlled hand. The best way is to use some milled flatwood, say a length of 1X4, clamped over the frog and point end, and leaving the frog rails also clamped. You'll then attempt to force the diverging rails downward in a series of progressive presses until they keep a slight bend downward. Once in place, you'll have to shape the roadbed under the diverging route to accommodate the descending rails, slight though it will be. From there, continue down to the siding or ladder track, whatever it is.

When I need to transition under a turnout, I use the different thicknesses of roadbed, and simply fashion a grade with spackle or drywall patching mud under the turnout.
 
I do not transition under any switches themselves, but rather start the transition about 2" past the joint. I insert strips of cardboard beneath the thinner cork to support the height reduction, but I don't worry too much because as Dennis posted, the track will support itself to a small extent and ballast will cover all sins.
I agree I do NOT want any transition occurring under the turnout, so it needs to occur after the turnout.

Someone suggested the use of 'door shims'. I had some combo wood-plastic ones I experimented with a bit today, but I have found their grade a little too steep thus creating a vertical kink at the exit from the 3-way regardless of how close/far it was placed from that join with the exit of the 3-way.
 
Brian ... I would use shims as Willie described maybe made from sign plastic cut about 1/2 inch wide and the width of the ties. You could vary the thickness by stacking/glueing several pieces together.
You are only looking at 3/32 of an inch difference of the two roadbeds? Hardly worth fighting about ... you are building a masterpiece - don't get bogged down trying to make a mountain from an ant hill!
Just be sure and leave about a car length from the frog before making the transition.
 
Brian ... I would use shims as Willie described maybe made from sign plastic cut about 1/2 inch wide and the width of the ties. You could vary the thickness by stacking/glueing several pieces together.
You are only looking at 3/32 of an inch difference of the two roadbeds? Hardly worth fighting about .
My concern over ANY vertical kinks in the trackwork was gained from numerous experiences with my old central midland layout. I was continuously surprised with the need for smooth, level trackwork. Longer cars and very slight variations in coupler heights, and really small flanged wheels can all exasperate the situation.

I've also spent considerable times 'reconditioning' used turnouts, and one big lesson I got there is NEVER to place a turnout on a variable grade,.....only a pure flat one. I'm speaking of the grade directly under the turnout itself,...not the fact that the turnout as a whole can exist on a grade.
 
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With so many tracks in such a tight space and so short yard tracks I'd not bother with differnet track elevations, I'd just grade the whole yard to match the mainline cork thickness. Some variation in terrain could be created with drainage swales between the tracks in spots. Either leave the cork out between the tracks or carve the swales in the cork before laying the tracks......DaveB

I'm giving some serious considerations to what you posted DaveB,...at least for the freight yard tracks themselves. Then only dropping down to the half thickness cork in tracks feeding the rolling plant and engine service building,....then maybe all the way down to plywood level for the blast furnace and electric furnace.


While experimenting around with this idea of having more cork roadbed than I originally planned, I've hit upon another idea for routing some of my turnout manual control rods,....across the surface of the plywood rather than underneath it.


Several days ago I took these two photos of the general orientation plan of those control rods as they would be mounted under the plywood deck,..but what if they to be routed on the top of the deck, in their own tube, and thru slots in the cork roadbed??
image%2842%29.png






image%2843%29.png

(I took those photos so I would remember approx where to drill holes for those rods in an aux steel beam angle-iron have under that edge of the plywood)


turnout control rods thru slots in cork roadbed
......just to give it a rough idea,
(Note: The slots between the cork pieces are just representative, bigger than need be. And the dark cork with the representative turnout on it is the thicker mainline cork, while the lighter shade cork is the thinner cork that might be found on the secondary tracks)

1/8" plastic tube with steel rod
image-20201107151608-1.jpeg


....3/32" plastic tube with piano wire activator
image-20201107151716-2.jpeg


....white coated steel rod within a brass tube,..
image%2844%29.png
 
I'm looking for advice about how to best handle these 'transition areas' where the cork roadbed makes a change in thickness. I've been worried about getting this correct for a long time. There was even a time when I considered not using any roadbed at all just to avoid this 'uneven' track base.
On my small N-scale layout, I solved this problem by cheating.

First I laid all track on cork roadbed at the same elevation. Then I built up the terrain in and around my yard so that the tracks there appear to be at "ground level." I found it easier to create sloping terrain than to make transitions in the track level. The illusion works well enough for me.

- Jeff
 
TBH, I'm a bit curious as to why even bother with cork when there's better materials available. I've personally been using foam trackbed from Woodland Scenics, but I suspect there are other options. It's easily bent into the right radius, glues down easily and damps the sound from the tracks a bit.
 
I experimented with a variety of foam roadbeds that existed about 8 yrs ago. I was not impressed as that seem to lack the firmness that cork offers.

More recently I had read of a number of folks that utilized a relatively cheap caulk to lay down both their cork and track. I did that a few days ago, and results look very promising.
 
There was a time when I thought I would not even bother with any roadbed cork. etc,...and just lay the track right on the plywood. Then I ran across a great deal of cork at a local train show,...so why not.

I'm actually still thinking about the gravel ballast,...such a mess. But it certainly looks much better. I do recall painting my code 100 rail (with a toothbrush) on my previous layout, ( https://model-railroad-hobbyist.com/node/31007 ) and it made the track appear smaller in height.
 
More recently I had read of a number of folks that utilized a relatively cheap caulk to lay down both their cork and track. I did that a few days ago, and results look very promising.
On my layout, I laid cork and track using the cheapest latex caulk I could find at my local super store. It worked just fine. My only regret is that I used white caulk. A better color choice would have been brown or gray so that small mistakes when ballasting would not be so noticeable, requiring a bit of touch-up.

For ballast, I used Arizona Rock and Mineral products, which I found to be excellent. In my experience, it was easier and faster to purchase ARM products from a reseller rather than directly from ARM. However, this was a few years ago, so maybe ARM has improved its customer service since then.

- Jeff
 
I wonder a couple of things:
1) If its that 'dense' how is it bent so easily if its not split?
2) I have found thus far that the split helps with locating over my paper drawing, then extracting the paper drawing in order to glue it down.
3) not too excited about that 1/4 inch height after working with high 3/16" of cork.

BTW: Disclosure, I already have lots of cork on hand, both HO size and O scale size.
 
Eva foam is available in sheets with varying densities and thicknesses , 2 mm up to 10mm , I use 2, 4, 6 , 6mm is a little over a 1/32 thick than the cork.


Either will work, if you have HO or N scale cork I would use it. If you need a taper you cut frozen pizza boxes into strips stack and glue them together , if you need something thicker Hobby Lobby or Dollar General and get poster board and cut into strips and stack to make the taper. You can make the tapers up to almost 3ft. for thick you can even go to mat board.

Foam : I use 6mm on mainline , 4mm on sidings/industrial/ hidden tracks , 2mm on industries

Cork : HO for mainline ,N for sidings , gasket cork or just poster board on industries .
 



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