The next step, with all the splines for the roadbed in place, was to file the roadbed top flat. I don't know - perhaps you are "supposed" to lay down and glue the splines so carefully that the top would turn out perfectly flat all by itself. Well, I can tell you that mine did not. But that was at least partly due to the fact that I ripped the splines myself, using a hand saw. Anyway, I used a rasp to file the roadbed top. I did not do file it level - on the contrary - I tried to make it super elevated.
I then secured the roadbed to the risers using counter-sunk screws, as shown below.
Then I used a clear finish to seal the the top (and the sides) of the roadbed. Here is a picture of the complete layout, after that step. To the left you can see how the mainline and the siding winds it way down along the front of the layout. To the right is the staging area, that will eventually be hidden behind the Tehachapi hill sides.
I was not sure how to proceed after that. Should I lay track directly on the splines? I know people do, but I was unsure. The roadbed did not look wide enough. Would I manage to attach the scenery to the sides of the roadbed and still create a descent ballast profile?
I finally decided to lay cork roadbed on top of the spline roadbed, which now turned out to be a sub-roadbed.
That would give me three advantages, I figured
- I would get the required ground work for a nice ballast profile
- I would get a protruding lip that would help when attaching the scenery base to the roadbed. Joe Fugate, of Siskiyou Line fame, does a similar thing with an extra spline ripped at a 45 degree angle.
- Sound silencing would increase. I am a little concerned that the fact that this layout has a closed bottom, would turn it into a giant violin or load speaker enclosure. Well, if it turns out that way I have to run it "with flaps down". But the cork would help.
Here are a couple of pictures of the cork installation process. Which is still ongoing.