Many people appreciate the beauty of French doors. They are generally considered more attractive than sliding doors for exterior use and can create grand entrances into interior spaces. While purchasing a complete set of French doors is an option, building your own can help you keep the associated costs lower while allowing you to customize the finished product.
However, this project involves multiple high-dollar tools as well as substantial planning upfront, making it suitable for only well-prepared DIYers. Additionally, you’ll want to invest in high-quality wood, especially for the face veneers and any door that will be exposed to the elements. To help you get started, here’s what you’ll need to build French doors successfully.
Choose the Wood
If you’re going to install the doors with one side on the exterior of the home, you want to select a rot-resistant wood. This allows you to avoid chemically treated options while still supporting longevity.
Options like teak, redwood, cedar, Cyprus, mahogany, and white oak can all be suitable and are typically widely available at local retailers. Once you have all of the wood, you want to select the best-looking pieces to make face veneers. Look for boards that feature tight, straight grain and that are a minimum of one inch longer than the completed stiles and rails will be as well as several inches wider.
Use a bandsaw to create veneers that are just slightly thicker than 3/16 inches. You’ll need two pieces of veneer, each 6 inches wide, for every face of the rails. Once the veneer is cut, you can use a drum sander to create an ideal finished surface.
Create the Core Staves
Now that you have the veneers, you can create the core staves. Taking fresh boards, cut the staves to 1 7/8 inch widths. The number you need for each stave will vary depending on the desired finished width as well as the size of the finished door. As a rule of thumb, make sure each is oversized by a minimum of a ½ inch when complete.
Additionally, your side and top rails will likely be the same width, but your bottom rail should be significantly more robust to provide support and decrease the likelihood that lower portions of the door glass will be kicked on accident.
Take the required number of the cut pieces to reach the desired size and turn them on their edge. Using wood glue, adhere the faces of the boards together. Take short pieces of angle iron to keep the pieces flush and clamp the pieces together.
In total, you’ll need four core staves for each door (two for the side, one top rail, and one bottom rail). For a pair of French doors, that comes to a total of eight core staves. Leave the core staves clamped while they dry overnight.
Scrape Excess Glue and Prep for Veneer
After the staves have dried, you’ll need to remove any excess glue that leaked from between the boards. Use the jointer on one side to achieve a flat surface. Then, take a planer to scrap the other side, working until the final product is 1 ½ inches thick.
Once both sides are flat and the desired thickness has been reached, joint one edge. Next, rip to a minimum of a ¼ inch wider than the finished core. Repeat the process for each core stave.
Now that the surfaces are flat, you can apply the veneer. Use wood glue to stick the veneer to the stave and apply clamps to keep everything together. For an especially flat surface, you can use I-beams to even out the pressure. After the veneer has dried, trim any excess material and adjust the stiles and rails to reach the needed finalized widths.
Prepare for Routing
To make sure everything is square, you need to set up the router properly. Begin by making sure the tool is square to the table and install the ½ inch drill stock into the collet of the router, rechecking to make sure everything is square from side-to-side and front-to-back.Then, create a setup board using spare stock. It needs to be the same thickness as the finished rails and stiles, typically 1 ¾ inches thick.
Add the stick cutter and install it with the bottom slot cutter set to 9/16 inch above the table. Then, position the fence flush with the bearing of the bit and clamp ¼ inch spacers to the fence, ensuring the first pass only makes a partial cut. After the first pass on each piece, you’ll remove the spacers to perform the next pass, finishing the cut.
Identify which side of each rail board will be the front and mark them. Then, use a straight edge and utility knife to mark the tenons. Make sure the shoulder of the front side is a ½ inch deeper than the shoulder on the back.
Set up the coping cutter, using the spare setup board to reach the proper height. Then, use spacers on the fence to make a partial cut during the first pass. Remove the spacers and complete the rout for each of the rails.
Building The Panels
Before you remove the coping cutter, you want to create a coped sled to provide support to the muntins during the routing process. Take a 5-inch wide and 30-inch long board that is precisely the same thickness as the rails and rout the edge. Using a mortising bit, square only the back sides of the tenon shoulders on each rail. Then repeat the process to successfully rout the ends of each vertical muntin.
Vertical muntins have short tenons, typically only a ¼ inch, since the majority mount to the horizontal muntins. Going back to the stick cutter, you’ll rout the desired profiles on the inside edge of each rail and stile as well as the muntins. On the muntins, you’ll rout one of the edges of each wide blank and then cut a 1 ½ inch wide muntin. Repeat the process for each muntin you require.
After that is complete, you’ll add the shaped edge in the coped sled you created earlier to help rout the rest of the profile. As with other processes, you’ll want to use spacers and make two passes before reaching the desired depth.
French Door Final Assembly
Now that the routing is complete, you can use the bandsaw to cut the rail tenons down to the final width. On the edge rails, focus on the outside edges when making your cuts. For the bottom rails, divide the wide tenon into the two narrower tenons. You’ll want to leave 1 ½ inches between them. On the rails, stiles, and muntins, you want to lay out the mortises. Use a pencil and straight edge to measure out the area for each mortise, marking them accordingly.
Use a drill press with a ½ inch Forstner to clear out the majority of the mortise. Then use a ½ inch hollow mortise chisel to complete the rest. For the rails, the mortises will be 3/8 inches deep. For the muntins, you’ll want to use the coped sled for support. Begin by measuring the glass recess. Then, subtract the thickness of the glass along with the glazing tape. Finally, subtract an additional 1/8 inch.
Mill a board to reach the needed thickness. Next, rout both edges and cut the number of strips required to secure the glass panels. Begin the assembly by gluing the top and bottom rails along with the muntins. Use a water-resistant clear glue for the best result, applying it to each piece with a brush for increased precision.
Add the side stiles, without glue, and clamp everything together. The stiles provide additional support and help keep everything square while it dries. Once the first section dries, you can glue on the stiles, clamp them in place, and let them dry. After the entire assembly has dried, you can add the glass. Apply glazing tape into the recesses, add the glass, and secure the retaining strips using small finishing nails and a hammer.
Now that all of the pieces are together, you have two completed French doors that are ready for installation. You can choose to finish the door in a variety of ways, including with stain, sealant, or paint, but that may not be necessary depending on the wood selected and whether the installation is indoors or outdoors.