Build the face frame first (Step 3) and use it as a guide for assembling the doors and cutting the curve on the back panel.
A full sheet of 3/4-in.MDF or particleboard set on sawhorses makes a good workbench for this project. Set up for marking the arcs (for the curved pieces) by drawing a center line parallel to the long edge of the sheet. Center a 4-ft. length of 1×12 on the line. Line up the top edge with the edge of the workbench and clamp it. Screw the point of the homemade compass in the center line 21-5/8 in. below the bottom edge of the 1×12. Draw three arcs for the face frame top and door top pieces (Figure B). Then replace the 1×12 with another 48-in. 1×12 and relocate the screw point (Figure B). Draw two arcs to outline the 1-1/2 in. wide curved roof trim molding.Cut out the curves (Step 2).
Even with careful jigsaw work, you’ll have to sand the curves for a smooth arch. Use 80-grit sandpaper on a sanding block to even out the curve and remove saw marks. Then sand again with 100- and 120-grit paper. For the best-looking finish, sand all the boards before assembly.Use a random orbital sander or hand-sand with the grain of the wood.