Place the 19 1/4-inch pieces (top and bottom) on a worktable. Apply glue to the 1 1/2-inch side of the 20-inch lumber (braces). Put them on the top and bottom pieces 2 inches from the 19-inch edges (front and back) and even with the 24-inch edges. Secure them with the finish nails.
Apply glue to the 24-inch edges of the top and bottom and on the edge of the braces. Align them with the top and bottom of the 30-inch pieces (sides). Secure them through the sides into the braces with the drywall screws. Clean up excess glue immediately with a damp cloth.
Set the rack rails inside the rack cabinet even with the ends of the braces. Mark the holes in the rails used for mounting them. Remove the rails and drill the holes with the appropriate drill bit. Do not mount the rails yet. Paint the entire cabinet (inside and out) with flat black water based paint (spray, roll or brush).
Position the cabinet on the worktable so the bottom is facing up. Measure from one of the sides and make a mark at 10 3/8-inches. Put the framing square on the mark and draw a line across the bottom of the cabinet. This is the starting point for the carpet.
Spray the adhesive on half the bottom and down one side. Read the label for the waiting period before applying the carpet. When the adhesive is ready, align the end of the carpet with the line drawn on the bottom of the cabinet and lay it on the wood. Turn the cabinet over as you lay the carpet on the side with the adhesive on it. Continue this until you make it back to the starting point. Cut the excess with scissors.
Cut the carpet from the edge of the carpet to the cabinet corners with scissors. Apply adhesive to the inside of the cabinet and stick the carpet as before. Allow the adhesive to dry thoroughly.
Locate the holes drilled for the rack rails and cut them out with a utility knife. Install the rails with the T-nuts and bolts. Next, place the handles on the sides of the rack cabinet slightly to the front of the center of the cabinet (most of the weight is on the front of the cabinet). Mark and drill the holes for the handles and install them with the T-nuts and bolts.