How to Build a Cabinet With Fiberglass

Measure the length, depth and width of the space you intend to fill with your fiberglass cabinet using a measuring tape. These measurements are the dimensions of your cabinet.

Cut two sheets of flat sheet fiberglass to the length and depth measurement of your cabinet using a circular saw or rotary tool with a diamond-cutting blade. These two sheets are the top and bottom panels for your cabinet. To prevent splintering along the cut line, apply a strip of masking tape to the surface of the fiberglass along the cut line.

Follow the same procedure to cut two sheets of fiberglass to the depth and height measurements of the cabinet. These sheets are the side panels for your cabinet. Cut a final sheet to the length and height of the cabinet for the back panel.

Lay the back panel flat in front of you. Slip one half a metal corner brace under the back panel. Use two metal braces along each of the panel's four sides. The horizontal portion of each brace should be under the back panel and the vertical portion of the L-bracket should be sticking straight up.

Adjust the position of the braces so they are evenly spaced around the four sides of the back panel. Pre-drill holes through the fiberglass panels where you have positioned the braces. Attach the braces to the outside of the panel by driving 1/2-inch screws through each brace from the outside of the panel, using the appropriate screwdriver.

Stand the top, bottom and side panels upright on their longest narrow edges in a rectangular shape on top of the back panel -- still flat on your work surface. Align the narrow edges of these panels with the top, bottom and two sides of the back panel. The outside edge of all four panels should be flush with the vertical portion of the corner braces.

Attach the top, bottom and side panels to the corner braces using 1/2-inch screws and the appropriate screwdriver. Use two additional corner braces to secure the frame at each joint where the top and bottom panels meet the side panels. Attach the braces using 1/2-inch screws.

Measure and mark the position for the shelves of your fiberglass cabinet, if you intend to use any, along the side panels using a felt-tip pen. Cut the shelves to the depth and length of the cabinet. Measure the distance between the inside edges of the side panels to determine the exact length for the shelves.

Install two metal corner braces along the underside of each shelf on both ends. You may predrill holes for the braces if you prefer then use 1/2-inch screws to attach the horizontal side of each brace to the underside of the shelves.

Dry fit the shelves inside the the fiberglass cabinet frame, holding them so they align with the marks you made earlier. Pre-drill the holes for the vertical side of each metal corner brace along the side panels. Hold the shelves in place and drive 1/2-inch screws through the corner braces into the inside edge of the side panels to attach the shelves.

Cut another piece of sheet fiberglass to the same dimensions as the back panel. This sheet is the door for your cabinet.

Screw two metal hinges into the top surface of the cabinet door along the left side. Position the hinges about 2 inches from the top and bottom corner. Lay the door flat against the open side of the cabinet and screw the other half of each hinge to the outside edge of the left side panel.

Place your completed fiberglass cabinet in the desired location. If you want to mount your cabinet on the wall, use a stud finder to locate the wall studs first. Mount the cabinet by installing additional corner braces in each of the four corners. Screw one side of each brace into the cabinet and the other into the wall studs.