For the plywood base, I chose to use 1/4 thick luan plywood. This has a smooth surface and is light weight. This plywood is also too flexible, so to make it rigid, I added a frame around the underside using 1" by 2" poplar strips. Another poplar strip was added across the middle. Both wood glue and small nails were used to attach the plywood to the frame and the edges were sanded flush. I didn't want the kids to get any splinters from the edge of the plywood, so a strip of masking tape was run along the edges. This is only temporary since I plan to add molding after the model is finished. The base we used can be seen (somewhat) in Getting Started.

The kit includes three pieces of wood that form the base for the Tabernacle walls to fit in. A groove is already cut in the base to accommodate the walls. According to Exodus 26:19, each board of the wall rests in two silver bases or sockets. To give the model a more accurate appearance, it was a fairly simple matter to cut grooves across the base. I didn't cut completely through the wood. By cutting only part of the way through, (the same depth as the lengthwise groove) you still only have three pieces of wood to glue to the plywood. Later when the walls go up and we are ready to landscape with sand, we can build the sand up to the bottom of the grooves and it will have the appearance of two sockets under each board. Be sure to see: Things we would have done differently.

Here the cross grooves are cut in the side pieces of the base.
Notice that the saw blade is set to cut only part of the way through.
I clamped both side pieces together and cut both at once.
Note: the saw blade guard is removed for this photo.
In this photo, half of the grooves have been cut. (Every other one)
The other half are marked ready to be cut.
In this photo, all the grooves have been cut in the end base. As you
can see there are 2 sockets or supports under each board as
described in the Bible. Once the landscaping sand is applied on
the model, the solid lower half of the base will not be seen.

Painting the Wall Boards and the Base