With the helix (technically) finished, it’s time to build a mountain and a tunnel. The tunnel will be the lower entrance to the helix.
First I put baking-paper on the sides of the helix and the wall of the layout room in order to be able to remove the mountain after the foam is set. After that I uses two cans of liquid insulation foam. After the foam is set it’s time to carve the rocks in to the foam and make the way in to the tunnel free of foam.
I removed the mountain for easy access. Now it is time to ballast the track in the tunnel. But before that I painted the fascia and the helix black.