WRR Retaining Walls and Skid Aprons – 2013

In the last installment we rewired the track and set the final pieces of the new banking in place. We can actually take a lap or two now, and work out any of the high or low spots in the track or any misaligned track joints. Most of these will be minor since that was attended to during the build. However, things can shift during the final stages of assembly, so it’s best to double check. So a few laps are turned in on each lane and it’s time to go to work on the skid aprons and retaining walls. The skid aprons will allow us to hang the tail end of the car around those new turns and keep the wheels level with the track surface. The retaining walls will hopefully keep the occasional airborne car on the track or at the very least, the table surface, and not rocket across the race room. The concrete floor in my basement is very unforgiving. First let’s get those skid aprons in place…

We will use Midwest H.O. scale cork roadbed for our skid aprons. This can be found in most hobby or model train shops. The cork pulls apart to form 2, 36 inch sections. We will actually be using the bottom side of the cork for the outside radius of the turns. That will give you a full inch of skid pad to slide on. You will also need some spacer material, 1/16th of an inch thick, to bring the cork level with the top of the track surface. We will be using Midwest balsa in a 1” X 36” X 1/16” strip.

Here you can see the cork up against the Tomy AFX track section. There is a 1/16th inch height difference between the two. You want the skid apron to be flush and even with the track’s racing surface. The skid apron is an extension of that surface and should be level.

In this picture you can see where the balsa spacer makes up the 1/16th inch difference. We will cut spacers and place them under the cork to keep the skid aprons level with the track surface.

Here you can see the cork is now level with the track surface. The balsa spacer is sandwiched between the cork and the banked curve support.

Measure your balsa spacer to match the length of the exposed support bracket and then cut it with a hobby knife to the measured size.

A little white glue will hold the spacer in place on the wooden banked curve supports.

Here are a couple of different angles showing the spacer glued in place.

A small bead of CA (super) glue will hold the cork against the side of the track. Make sure to keep the upper surface of the cork level with the track surface until the glue has a chance to set. After the glue has set (about 10-15 seconds) nail the cork to the banked curve support, using a small flat head nail as seen on the left.

Once the glue has set and your cork is nailed down you should have something that looks like the picture above. The cork also paints easily. We will be painting both the track and the cork skid aprons, a dark gray later on in the course of this project. We recommend that if you are going to paint your track or skid apron, that you do so before installing your retaining walls.

We are using a new material (to us anyway) to build the retaining walls. We will be using vinyl baseboard that is used in kitchen and bathrooms. The baseboards come in a large variety of colors. I saw blue, gray, bright white, off white, tan, light green and pink. We chose an off-white color that doesn’t look as stark as the bright white. We are hoping that it has a more realistic appearance with the rest of our scenery. As you can see in the photo above, the baseboard has a lip at the bottom edge. We will be removing that and will explain the reasons in the next steps.

The backside of the baseboard, the side that is normally glued to a wall, has multiple ridges across the surface. This is the side opposite of the lip at the bottom of the baseboard. We wanted the smooth side of the baseboard to face the track, so that would place the lip against the pieces we would attach the retaining wall to, leaving a gap at the bottom. To resolve this, we took a drywall “T” square and used it as a guide to cut the lip off of the baseboard. The material is made of a soft, pliable vinyl, so a utility knife cuts through it very easily.

Once we removed the lip, we dry fitted the retaining wall around the banked curve supports that it will be attached to. Start in the middle of the turn, centering the first piece and work your way down each side. This will give you an even number of “gaps” or “seams” around the area your are placing the walls. Getting the symmetrical, finished wall will keep your eyes from getting distracted once you start racing on your track. Next we will go over attaching the retaining wall pieces to the banked curve supports and getting a finished look at the transition points between the front and back stretch and the banked turns themselves.

In the drawings above, we illustrate how we started the retaining wall by centering it on one side of the entire curve area of the oval. This will keep the wall lengths and shapes even throughout the turn and make it symmetrical and more pleasing to the eye. Once the first section is centered, cut to length and attached start the next section as shown on the right. Follow this procedure until you have the retaining wall end where you have planned. Make sure to leave enough space on the baked curve support to attach both pieces of retaining wall where the joints meet.

We will be using white aluminum screws to secure the retaining walls. These were leftovers from a vinyl fencing project from last summer. They match the retaining wall color pretty well and we have a few dozen available to use. A word of caution about aluminum screws, they do not take a great amount of torque, before snapping. Make sure to drill your pilot holes a tiny bit smaller than the diameter of threads of the aluminum screw. And turn them slowly until they are snug.

Here’s a finished wall section. Once the first “centered” piece is in place, work your way around the rest of turn and transition sections.

Here are a couple of pictures of the track from each end of the table. Notice the retaining walls from the turns and how they transition into walls running along the front and back stretch of the oval.