Building the Straight Coving
The straight coving is a bit less complicated then the corner coving.
I started by gluing two layers of MDF for the bottom, and cutting 45 degree dadoes in the bottom and top. The shape of the top dado allows the smaller strips to lock in place (somewhat) while gluing. Note that with the small strips oriented this way, their grain is in the strongest configuration, and they do not break off as easily as if I had glued several blocks parallel to the base.
The small bottom dado will allow me to clamp the smaller strips.
I also used these clamps as well. I made three 4-foot coves so I would have some extra to allow for waste.
Now the glue up is finished. Later I sliced off the extra stock on the outside of the small strips on the tablesaw with the blade at 45 degrees.
Next I rand the stock through the planer to flatten the surface indicated with the arrow. This was done so all three pieces would have the same depth, which is important in the next step.
The next step was to install two rails across the table saw on either side of the blade. I used T-Nuts that had their prongs clipped off to ride in the miter gauge slots.
This is the first setup I used to cut the coves. I pushed the cove stock from right to left over the blade. You can see my dust collector over the blade… this did not work well, as the blade spews tons of dust straight to the left. Dust Storm! I needed a better dust control method.
A far better way turned out to push the stock from the left, with an L shaped baffle being pushed ahead of it. The measuring tape is there to give it some weight. This worked very well (with the insert removed). Very little dust escaped.
This is the result after the first cut. You do not want to cut more than about 1/8 of an inch at a time.
After a few more cuts:
Time to move the rails back a bit and take a few more bites:
After moving the fence again, almost done:
The final product after I trimmed off the extra stock (table saw blade at 45 degrees) and filled some tiny voids with glue. I had not always had the clamping pressure perfectly aligned.