clock menu more-arrow no yes mobile
This Old House homepage

How to Repair Cracks in a Built-In China Cabinet

Carpenter Nathan Gilbert and paint expert Mauro Henrique help a homeowner solve a common problem with built-in cabinets in older homes.

By Nathan Gilbert and Mauro Henrique

Nathan Gilbert fixes a crack in a homeowner’s china cabinet. Nathan shows the homeowner how to skin the interior of the cabinet with MDF, hiding the crack while replacing it with a modern material that blends in with the original charm. After Nathan wraps up, he gives paint expert Mauro Henrique a call to help the homeowner finish the job. Mauro helps the homeowner fill holes, caulk prime, and paint the interior of the cabinet for a fresh new look.

Many older homes use built-in cabinets or shelves to create mechanical chases in the corners of rooms. When those chases contain heating pipes, they can cause the wood used to construct these shelves to shrink or expand over time, leading to cracks and splits. It’s a common issue, and the fix is relatively simple.

How To Repair Cracks in a Built-in China Cabinet

  1. Start by labeling the shelves with a piece of painter’s tape and marker. Either number them or label them as top, middle, and bottom. Also, take measurements of the shelves’ heights and write them down before setting the scribes to the thickness of the MDF panel and marking them along the edges of the shelves. Then, use the utility knife to cut through the paint and caulk along the edges of the shelves before carefully removing them.
  2. Cut a 45-degree miter at the end of a scrap piece of MDF. Use this block to check the angles at which the back and sides of the panel meet, and place a mark at the edge where the scrap touches the side panel. If there is significant build-up in the corners, it may be necessary to go with a 47- or 48-degree scrap. Repeat the process on each side, top, and bottom, and take measurements from side to side. Also, measure the overall height of the cabinet.
  3. Setting the track or table saw to the same angle as step 2, cut a sheet of MDF to width. Place the panel in the cabinet and check for fitment. Measure and cut the side panels using the same method before test fitting them, as well. Once satisfied with the fit, remove the panels.
  4. Lay side panels on a flat work surface. Referencing the heights measured in step one, lay out the new shelf locations. Align the shelf pin jig and drill a hole at this height. Slip a shelf pin through the jig and into the hole to hold the jig in place before continuing to drill shelf holes. Repeat on the front edge of the panel before moving onto the other side panel and repeating.
  5. Squeeze a bead of construction adhesive onto the back of the panels. Place the back panel in first, screwing it into the shelf-back behind it with trim-head screws. Next, place the side panels in and secure them with trim head screws.
  6. Using the scribed marks on the shelves for alignment, place the track saw on top of the shelf and cut ½-inch (the thickness of the MDF) off the back and sides of the shelves. Slide shelf pins into the holes and test fit the shelves. Trim as needed and then remove them from the cabinet.

Mauro begins by following these steps:

  1. Take out the shelves and pins and set aside.
  2. Cover the counter of the cabinet in flooring paper and tape off the sides with painter’s tape to ensure that no paint splashes or drips onto it.
  3. Next, check for any nail holes and fill with wood filler.
  4. Then, lightly sand the surface of the MDF panels with 220 grit sandpaper.
  5. After that, vacuum the area and wipe down the panels of any residual dust. Mauro finishes wiping the panels and uses a 2.5 cutting brush to cut into the edges and a mini-roller brush to paint and apply a coat of oil-based primer. It is important to use an oil-based primer for this project because MDF is very porous and absorbent. It needs to be sealed to allow the paint good adhesion and better coverage. A water-based primer will sink into the material so it’s not ideal for this project. Let the primer dry for 30-45 minutes till its dry to the touch.
  6. Apply the first coat of paint using a 2.5 cutting brush. Carefully cut into the edges and then, using a mini-roller brush, paint the overall surfaces of the panels. Roll at a slight angle using light but consistent pressure. After you finish painting, wait 1 hour for the paint to dry until it feels dry to the touch. Apply the second coat of paint. Allow 1 hour for the second coat to dry until it feels dry to the touch. Once dry, reinstall the shelves.

Materials

Tools

Next Up In Cabinets