- Circular saw
- Miter saw
- Nail gun
- Table saw
- 1/4” plywood
- 3/4” plywood
- Wood glue
When you’ve chosen the size, determine how many 2x4s you’ll need to cover the plywood backer. You’ll get 25 triangles from an 8-ft. 2x4, which covers about 1-3/4 sq. ft. Our 4 x 12-ft. project required 28 8-ft. 2x4s. We wanted all the triangle edges to be square, so I bought 2x6s and ripped them to 3-1/2 in. wide.
Once you start gluing down triangles, your pattern will be locked in, so do a dry run first, without glue. Starting with a pinwheel shape at the center, keep adding triangles until the plywood backer is full, with each triangle offset from its neighbor.
Project step-by-step (8)
Paint the boards
After choosing your colors, paint both faces of each 2x4. We used dark blue on one face and light blue on the other.
Build a zero-clearance miter saw fence
Fasten a 1x4 to a piece of 1/4-in. plywood with glue and 1-in. screws. This not only gives you a zero-clearance fence but a throat plate as well. Attach the assembly to the miter saw fence with 3/4-in. screws. Set your miter saw to 45 degrees and make a cut.
Cut the triangles
Cut a 45-degree angle at one end of each 2x4. For the next cut, flip the board and align what will be the triangle’s top point with the kerf in the 1/4-in. plywood. Mark where the long point of the triangle’s base lands on the fence and cut the triangle. Repeat this flip-and-cut process until you’ve cut all the triangles you need. Sand all the corners just enough to break the sharp edges.
Glue on the triangles
Snap a chalk line from opposite corners to find the center of the plywood. Mark a vertical and a horizontal layout line at the center point as a reference to start the pinwheel. Glue the triangles’ bases–one at a time–and start setting them in place.
Applying glue is the most time-consuming part of this project. The Rockler Silicone Glue Brush made the task much more efficient and bearable.
Trim the edges
Flip the project over and trim off any overhanging triangles using a circular saw with a cutting guide. It won’t cut deep enough to cut all the triangles; you’ll need to finish with a handsaw.
Attach the French cleats
Because this thing is really heavy, we used two French cleats: one at the top edge and a second about 36 in. from the top. Leave the cleats short of the ends so they don’t show. To make the cleats, rip four 4-in.-wide strips of 3/4-in. plywood, and then cut a 45-degree bevel on one edge of each strip. Glue and clamp two cleats to the plywood with the beveled edge pointing down and facing the plywood. Secure the cleats using countersunk 1-1/4-in. construction screws.
Hang the project
Anchor the other two French cleats to studs in the wall using 3-in. screws, with the beveled faces pointing up and facing the wall. Measure carefully to ensure the cleats interlock properly. Hang the project on the cleats.
Attach the frame
Cut the 1x4 frame parts to length, and then nail them to the edges of the project with 2-in. brad nails.