Let's build reversible backdrops

With the layout frame and book-end sections now complete, I now need to think about adding a backdrop for my model railway. The easy way to do this with such a small layout is to screw a panel of plywood along what will become the rear section of the layout and hey presto, you're done. If you remembered however, I allowed enough space between the layout surface and the edge of the timber frame to install a removable clear perspex panel. Not only will it slide out easily for when you want to work on the layout or run trains, but it will also keep the layout completely enclosed, dust-free and safe from inquisitive fingers who can't help touching stuff. So why not make the perspex interchangeable with the back drop so that the layout can be viewed from both sides?

After pre-drilling the nail holes as shown at the top, I glued a 6 mm strip of timber into place to hold both the clear perspex front panel and the rear backdrop, both of which will be interchangeable.

To hold the clear perspex panel and backdrop in place, I bought some 6 mm x 6 mm strips of Tasmanian Oak from my local Bunnings store. With the 11 mm gap I allowed for when putting the layout frame together, it will leave me with 5 mm of play for both the perspex (that's plexiglass for our US friends) and backdrop to slide in and out of position. I then pre-drilled the nail holes for the same 15 mm long nails I used to hold the plywood to the layout frame, and glued the 6 mm Oak strip flush to the edge of the layout frame using fast setting PVA tacky wood glue, and allowed a gap of 3 mm at each book end for the end backdrops to be fixed into place.

The mouse hole. Important to remember if you want trains leaving the layout to head into a staging yard of some sorts, but more on that later.

Next up comes the most important part of the layout, that is if you want to run trains off the board and into some removable staging which I will add later. Using my life-size plans, I measured where the two rails I wanted to run off the layout would end, and sat a locomotive on a piece of track to measure the clearances required. I then added 15 mm in height, 9 mm to allow for the thickness of the plywood and an extra 6 mm just to be on the safe side. I then placed a piece of MDF board on the inside of the book-end frame, traced around it and cut it to fit. The same tacky PVA wood glue held it in place until I could measure and cut the 6 mm Tasmanian Oak strip that would also have to run up each side of both book-end sections.

The 6 mm Tasmanian Oak strip when glued and nailed into place provides a channel for the backdrop to slide into.

Once the other end section was lined with MDF board, I could then cut a 1.83 metre long section of timber using some 42 x 19 mm pine, ensuring it was the exact distance between each book-end section by taking the measurement from the bottom of the panels. Setting this at a distance of 3 mm below the top of the book-end panel, I then drilled and countersunk a hole at each end of the layout, glued it into place with the same tacky PVA glue and drilled home some 70 mm wood screws. This will later support both the clear perspex lid, and a strip of LED lights that will be affixed to the underside of the timber. I repeated the process again for the 6 mm Tasmanian Oak strips when fixing the inside backdrop supports into place, and setting them at a gap of 5 mm back from the front strips, glued and nailed these into place. When complete, they form a channel for the backdrop and perspex to slide down and nest into place. The 9 mm thick plywood I used for the layout base then acts as the inside wall of the backdrop channel.

The layout with removable backdrop now in place, ready to be painted sky blue.

As you can see above, the MDF panel is sitting correctly between the channels I have just made and is ready to be painted sky blue. But think of the possibilities here. With the backdrop now fully interchangeable with the clear perspex panel that will later slot into the front, providing me with a lot more variety when viewing and operating a small 6 foot x 1 foot layout. But I'm not quite ready to lay track yet. First I have to lacquer the timber, and that means one thing; sanding, and lots of it. 

See also; Painted, stained and varnished