Introductory note to the reader: As I made these two donut walls, I learned lots of ways how NOT to do things. I usually mention these lessons learned within the steps, and importantly my images might show the wrong way to accomplish something. If you're interested in learning the best way to build these donut walls, please read all the steps carefully so you can understand the pitfalls as they are called out.

Step 1: Assemble the Frame - Part 1

The first step involves making the wall. That is, reinforcing the plywood so that it will stand up and stand firm against a wall. I used 1x3 strapping strips to line the outside of the plywood panel with an additional two strips on the top and bottom of the wall for extra strength.

First, sand the veneered plywood with 180 grit sandpaper to make it smooth and ready for staining. Remember to wipe away all the sawdust.
Cut two lengths of the 1x3 strapping the width of the top and the bottom edge of the plywood. it’s probably best to use the plywood as a marker to cut the 1x3 exactly the correct length. In my example I marked them off at 36".
Flip the board over with the 1x3 aligned to the top and bottom edge, then drive five evenly spaced construction screws through the plywood into the 1x3 using your electric driver. Drive the construction screws a little bit below the surface of the plywood, i.e. countersink them.

Step 2: Assemble the Frame - Part 2

In this step you will cut the two vertically-oriented 1x3 strips. You can either measure the length between the two horizontal strips you made in the previous step, or place your strapping against one horizontal strip, and mark the other side.

In the picture, I measured 87 5/8th inches and cut the length.

After you have your two vertical strips, flip over the board, set them in the correct place.

As you did in the previous step, countersink construction screws from the front side of the board into the strapping at regular intervals. I spaced them about 10" apart. Make sure that there is a screw near the ends of all 4 strips, at around 1" from the end for rigidity.

Step 3: Layout the Dowel Grid

Spacing the dowels requires care. This step can be performed many different ways, but here's what I did.

I started with the decision that the grid should be:

7 columns of dowels, 1 centered and 3 to the left and 3 to the right at 4 1/2" spacing
9 rows of dowels, starting at 24" from the top, and spaced at 5"

Figuring this out was a matter of density vs what fits.

How to mark where to place the dowels:

Mark a yard stick with ink on tape at the the 7 spots (that is: 4.5, 9, 13.5, 18, 22.5, 27, 31.5).
Measure 24" from the top, tape a tab of tape on the outer edge of the board, and mark that 24" spot. Place one marked piece of tape on the right side of the donut wall, and a second piece of marked tape on the left side of the donut wall.
Repeat placing 2 tabs of tape every additional 5" down the outer edge of the donut wall.
Place your yard stick at the top marking of 24" from the top and secure (I used two small clamps to hold the yard stick in place).
Mark the 7 locations of the dowels, across the yardstick. I used an awl and an mallet to make an indentation each each spot.
Remove your clamps, and drop the yardstick to the next marking, 5" below where you were in the previous step. Repeat steps 4-6 until you've marked all rows.
Drill a pilot hole at each dowel marking. I used a small 3/16" bit.

Additional work

This is time consuming but

Sand down the filler you added in the previous step. I was a little sloppy with filling in my holes, but since I'm using a dark stain and I'm not a perfectionist, I can get a way with it
Vacuum up your sanding and wood bits from drilling the pilot holes. Do a good job here as we'll be staining in the next step.

Step 4: Stain the Board

Staining the board represents a do-what-I-learned, not-what-I-did step. I thought it would be better to mask the points where the dowels attach to the board, stain the full board, attach the dowels, and restain the square under the dowel. This is a waste of time, and it looks bad. Double fail. Just stain the whole board over your pilot holes with 2-3 coats of stain as necessary. I used a foam brush.

Picture of the WRONG way is included here for posterity

Step 5: Stain and Prepare the Dowels

Stain the long dowels first. I set them in a tabletop vice and stained them that way for a continuous coat for color. I used two pieces of material to clamp the dowels within the clamp for stability and so as not to ruin the dowels. Then just apply stain.

After the stain dried, I used a fine jig-saw blade to cut the dowels to 5" in length. I marked off every 5 inches with a pencil - you could see the pencil mark on the stain, but you have to look closely. (this yields 9 x 5" dowels)

Then I cut each full length 48" dowel into 9 pieces for the board. A band saw would have been ideal, but a hacksaw or jig saw was fine. Just use a finer blade because the dowels are made of hardwood and otherwise will splinter.

After I cut all 63 pieces (9 x 7), I had to drill a pilot hole in each to make the next step works. You can see how once again I set the sized dowels in the vice and used the drill press to assure a completely vertical pilot hole. I think with only a hand drill this would have been impossible.

Step 6: Fix the Dowels to the Board

The board should now have 63 pilot holes and you should have a box of 63 stained 5" dowels with a pilot hole drilled into one end.

Place a washer on each screw.
Position the screw pointed from the underside of the board toward the top. (I put the screw on the end of the driver bit)
Place a dab of wood glue on the pilot hole end of the dowel.
Hold the dowel, with pilot hole facing toward the board ready to accept the screw.
Use a drill to drive the screw through the board and into the dowels pilot hole.
Wipe off any excess glue.
Repeat steps 1-6, 62 more times.

NOTE: The board material is soft, so get ready to back off when screwing the dowels to the board.

Also, you will have to stain the tops of each dowel after you complete #7 above.

Step 7: Prepare and Fix the Message Board and Enjoy

( no procedural pictures)

We commissioned 2 signs to appear at the top of the donut walls, appropriate for the event. They were made by covering fiberboard with chalkboard paint , then handed off to an artist.

After we received them completed, I drilled 2 holes just larger than the dowels at the top of each sign. Using similar technics, I stained and secured 2 dowels to the top of the donut wall, then hung the signs.

On the big day we draped the signs with LED string light and had the caterer pop all the donuts on wall. It was a great success - and I was able to resell both walls a few months later for nearly what I paid for them in parts.