How to Pave a Road in N-scale

Posted on June 8th, 2010, by Mike

For my N-trak module, I intended to have a small road sit at the back edge and help make the transition from 3-D model to 2-D backdrop. Having never been satisfied with techniques I’ve used in the past to make a road, I decided to innovate.

I knew that I would have a bridge that broke the road up into two shorter segments, so I decided that I could model each segment as one piece, avoiding any discontinuity in the road surface except right at the edge of the bridge, where it changes from asphalt to concrete anyways. I decided to use 3/32″ chipboard as my substrate, because I knew I could work with it well, having been a student of architecture in the 90’s. I drew out my road plan in CAD and then transferred it to the chipboard by simply slicing through the paper that I had printed on. The benefit of chipboard is that it is a concrete gray color naturally, so damage to the finished product wouldn’t look too out of place.

I also cut about halfway down through the chipboard at the centerline of the road, enough to allow me to bend it here and form a slight crown to the road. Of course, this leaves a scar in the road, but no matter: the next step would fill that crack. I painted my road with acrylic paints, thinned slightly with water, to which I added a small amount of joint compound. Told you I was innovating!

I’d never painted with joint compound (drywall mud in other words), but I loved the results so much I do it all the time now. The surface came out with a definite grit to it, which took on weathering chalks very well. Once the basic coloration was to my liking, I sprayed it all with a clear acrylic gloss.

What? Yup, I needed the gloss so that I could add decals, for the striping. I had on hand a bunch of dulux yellow and white stripes from custom decal sets I had made ordered previously. I had the crown in the road to guide my yellow stripes, setting one first to one side and then, after it was dry, nudging the second one of next to it, tediously getting them aligned. If I had a double stripe on common film (i.e. some clear film between them), it might have been preferable to put down a double stripe just once, rather than a single stripe twice. But the single stripes were more flexible, and I had lots of curvature to deal with.

After all the decals were applied, I used Micro-Sol to dissolve away the carrier film, using several passes. But once this was done, I still had perfect yellow stripes, not the weather-eroded fading markings we are all used to. And I had a glossy surface. So, I sanded it down! I didn’t sand too much, just enough to bring the shine down and start to eat away the stripes in places. I left just a touch of sheen to the road, since asphalt can shimmer at times.

Module construction closeup

Here is an in-progress shot that shows the road completed, and how much sheen it still has. I placed gravel shoulders later, right up to the white edge stripe.

Boyce Junction N-trak - Old Chapel Avenue

(click to view the full size image)

And above, you can see the final road. Well, it isn’t complete yet – I still need to erect guardrails to protect that big embankment, and I need to deal with some wear and tear. Turns out the chipboard isn’t all that rugged, so if I were to do it over again I might choose a nice thick styrene instead. But you can see how the stripes are worn away in places, and the texture that results from the combination of joint compound in the paint mix plus a light sanding is very effective at representing asphalt.


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