Terrain Dilemma

[doctorwayne]

I used Durabond-90 directly over screen (cheaper than the plaster cloth, although perhaps not as easy to use). I used both aluminum and fibreglass screen - both worked well, although the fibreglass requires more support during application. For that reason, I prefer the aluminum variety. Once fully hardened, it's like reinforced concrete and there are several hard-to-reach areas on my layout where I've leaned on it for support to reach the backdrop. After the Durabond hardens, the support can generally be removed if you have access to the underside (open grid or L-girder benchwork). I used scrap and not-so-scrap lumber, held in place with C-clamps. for these Alp-like creations:




Eventually, a thick forest will tone down these steep contours to more closely resemble the Niagara Escarpment. (Incidentally, the bridge piers and abutments were also created using Durabond.)
To create slight undulations atop areas where the benchwork was covered by plywood, I simply placed some scrap wood blocks before stapling the screen in place. You could also use wadded newspaper, cardboard, or foam sheets. For very slight hills, just apply the Durabond in a thick coat directly on the plywood, with or without screen (it won't crack, no matter how thickly or thinly it's applied, and it still hardens at the same time, as it contains a catalyst).




If you're placing Durabond in direct contact with wood, spray the area with a little "wet" water before applying the plaster - this prevents the wood from drawing moisture out of the mix before the Durabond has set. It's also a good idea if you're applying the Durabond atop or adjacent to previously-applied and hardened Durabond.
All of my "water" scenes are Durabond directly atop plywood (no screen) and the applications are generally about 1/8" thick.








For both landforms and water scenes, I use various putty knives, scrapers, and drywall knives to apply the Durabond and create the final contours - mix it thick enough so that it doesn't drip through the screen, but "work" it enough to press some of it so that it oozes through the openings a bit. If your screen is well-supported, it's not too difficult. To smooth the knife marks before the Durabond sets, I use a cheap 2" brush to liberally apply plain water to the surface, then use the bristles to smooth out any gross irregularities. Scenic foam, etc. will hide any minor flaws. To colour the raw Durabond, I used the cheapest flat interior latex house paint that I could find, then thinned it 30-50% with water. This is much easier to apply than the full-strength paint (use that el-cheapo brush), soaks into the Durabond somewhat, and gives you much more coverage. Most areas receive multiple applications of ground foam and/or ballast, but you can re-stain or paint any areas that require special consideration. The main thing is to get rid of the white glare.

Wayne