There's nothing worse than square corners on a simulated sky backdrop. I know that there are several schools of thought on how to round out the corners of the layout room, but I was looking for a simple yet effective means of doing so that didn't involve curving drywall. I saw an article in
Model Railroad Hobbyist Magazine that used PVC flashing secured with cove base mastic, and I thought that I would give it a try. The PVC material comes in a roll and is 15-mils thick (0.015") and can be readily found at most home improvement stores. The rolls come in varying lengths up to 24-in. and as long as 50-ft. I purchased a product called Dura-Flash from Home Depot and was able to find it in a 20-in. long roll. Here's a photo of one of the corner roundings installed:
In this view the 20" width is in the horizontal and the length of the sheet was cut to extend to the ceiling (or at least where the drop ceiling will be located). The cove base mastic had been applied on the wall where the edge of the PVC was to go and afterward the sheet was placed on the wall. The mastic grabbed instantly but there was still time to tweak the panel if needed. Any excess mastic can be removed with a wet sponge or damp cloth.
After the panel dried a day or so, I applied drywall compound to the edges and sanded it smooth to make the edge of the panel disappear. When that was complete the rounded corner could then be painted the same color as the rest of the sky backdrop.
The
Model Railroad Hobbyist article can be found on their website at:
http://model-railroad-hobbyist.com The download is free. Just search for the December 2013 issue.
Here's a photo of one of my finished corners:
