CP Executive train in Albany

CP Executive train in Albany

Wednesday, November 8, 2017

Cork and Vinyl roadbed

In preparation for installation of the roadbed, I painted the plywood with brown paint. When I was younger, I had followed articles in Model Railroader and had selected tan or reddish-brown paint for my previous layouts. And, no matter what I did they didn't look realistic to me so I used copious amounts of ground foam to hide any bare patches. Then it dawned on me... the dirt in New York isn't very tan or red. It is brown! So, I followed Lou Sassi's advice and looked for a dark brown. He used something called "Tobacco brown" and I have no idea what that is, but I found a "Turkish Coffee" color that was very dark. Perhaps too dark. Depending on the lighting (compare the other pictures in this blog entry) it varies a lot. I used up a quar, but when I need more I will change to something lighter.

I painted over the top with a pretty heavy coat to get into all the cracks of the plywood. I was careful to try and avoid painting over the track center lines, as they were carefully laid out. However, any building lines were completely painted over as I may rearrange them slightly. For the "Mohawk Paper" section, I also tried to preserve the  street markings because it took so long to draw them. They too are subject to change in the future, but right now it gives a simple visual idea as to what I will be modeling there. I also need to calculate the grade and make sure that what I had planned will work.

Unlike tan paint or bare plywood, it is hard to see markings through or on the dark brown paint. The sidings by Keis required some rethinking, and it came down to whether I wanted to use a righthand or lefthand switch once the track separated from the mainline. I tried drawing lines on the brown paint using blue sharpie, regular pencil, and silver pencil but it was no good. So, I grabbed some tan paint I had leftover on the shelf and painted the small section a lighter color so that I could see what I was doing. In the end, I reverted back to the original track plan. The yellow boxcar is used to show the length of a 50' boxcar, useful for planning siding lengths.

I had a couple of choices for roadbed. On my N scale layout I had used Vinylbed by Hobby Innovations and really liked it. It went down in one piece, was a nice gray color that looked like ballast, didn't dry out, and was firm and supportive. I planned to use Vinylbed (now called Flexxbed) for this layout but they reformulated it. It is not as squishy as foam roadbed, but much softer than cork. So, I bought a box of Midwest HO cork roadbed. Cork works well too though it requires sanding the edges to remove the rough spots. I still have some of the N scale Vinylbed (old stuff) left over, so I will be using that for secondary tracks and sidings.

For joints between layout sections, I wanted something stronger than cork. The track may flex in these areas or need adjustment, and cork just doesn't hold up to repeated changes. So, I went with wood. I tried to find sections of straight wooden roadbed that I could cut into pieces for each joint, but all I saw on Ebay were curved. Perhaps that is a good thing, as they were likely 1/4" thick and I need 3/16" to match the cork (roadbed has gotten thinner over the years apparently). So, I bought some 3/16" plywood on Ebay and cut it to make pieces 1.5" wide. This isn't as wide as normal cork because I will add slopes on each side. In certain areas shimming was necessary with some cardboard.

I used clear caulk to attach the roadbed to the plywood. I avoided any caulk that had the word Silicone on the bottle. So, I bought a bottle of Loctite "all purpose adhesive caulk" that doesn't have silicone. I quickly discovered though that once you squeeze out a line of it and spread it out, it is very tough to see track centerlines for laying the roadbed! So, I did one half of the roadbed at a time. For the Vinylbed, I split it down the middle and widened it to better replicate HO scale width roadbed. I used a spare piece of HO track (painted yellow so I wouldn't lose it) to verify the width I wanted. I also used the caulk to fill in the gap in the middle of the Vinylbed roadbed, which will save me some ballast later on.

I don't have a lot of experience with modeling grades in track, so this will be a bit of an experiment for me. There will be three different track heights (HO cork, N scale roadbed, and on the bare plywood) and I hope it pays of visually. I used cardboard to build ramps between the different thicknesses of roadbed. The ramps aren't perfect but I made sure to not have any abrupt drops, and I also didn't put any cross-elevation in areas where the grade drops because that is just asking for trouble. I think once track is laid and ballasted, it will look pretty good. If necessary, I can always use more cardboard shims under the track.

For the turnouts I used HO cork and split it at the start of the switch, and then filled in pieces. It worked okay, but for the N scale roadbed I instead used some cork sheet that I had and traced the turnouts onto it. I know they sell turnout cork pads but they are pricey. At the areas where the throw bars will be, I cut a 3/8" wide slot and dug up the cork and caulk in the area. Then, I inserted small pieces of cork into the slot on the ends to hide the gap. I will eventually put a thin piece of styrene over the top with a hole drilled in it for the switch machine motor, and that will keep any stray ballast out. I also put a small sliver from the edges of the cork along the wood block joint areas.

I had to sand the edges of the cork to get a nice smooth slope for the eventual ballast. Yuck! What a boring and dirty job. Plus, because the layout was so high it was hard to get in and sand it so I ended up standing on a step stool. My layout doesn't even use that much cork but by the end I was done with it. Now I remember another reason why I loved the Vinylbed so much! The rubber grit got everywhere but my trust shop vac made quick work of the removal. In the end, I am glad I put the work into doing it as it will make ballasting so much easier.

As the last step, I painted the top of the roadbed with gray latex paint. This not only will make it look better, but it also seals the cork and hides any brown spots when it comes time to ballast.

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