Before you read on, go to your kitchen and open a cabinet door. Take a good look at the hinge of the door, both the hinge fixture and how it sits on the door. Notice how the hinge fixture lies flush with the surface of the door. It does so because a notch was cut in the door in which the fixture sits.
It’s the creation of the notch we want to discuss in this article.
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Do Door Hinges Need To Be Recessed?
Look again at your kitchen cabinet door, and notice how it closes fully and without a gap between the door and the jamb (cabinet frame). That’s because the fixture is recessed in what is called a hinge mortise, just deep enough for the fixture to sit at the same height as the surface of the door.
Absent the mortise, with the fixture sitting on the surface of the door and jamb; it would not close fully and without a gap between the door and the outer surface of the cabinet.
So, yes, door hinges need to be recessed.
Before the advent of power tools, that mortice would be cut with a chisel and hammer. The hinge’s shape would be traced on the door and the jamb, measured as to depth, and a notch would be chiseled out.
Today, routers can do this with precision and uniformity of depth for hinges to sit perfectly and flush. The cut is quick and easy on both the door surface and the jamb, and doors can be hung in short order. The question, then, becomes what router bit to use?
Use a Hinge Template
Hinge templates are available to measure and map out your mortise cuts for your door hinges. They help you set the spot where the cuts will be made and provide the correct dimensions for those cuts.
Set the template on the edge of your door where the hinge is to be placed. You will already have measured the same distance down from the top and up from the bottom for hinge placement to create the right balance for the door hanging. You can adjust the template to the size of the hinge you are using and tack it into place.
This step will give you a proper measurement that will match the hinge perfectly in both spots (we’re still talking about a cabinet door for the purpose of this article). Two of the three crucial measurements are now set – width and length of the hinge mortise.
One more word on the mortise layout: if the hinge you are using has square corners, you’ll need a chisel in addition to a router. Most mortise templates are for hinges with rounded corners. As we will get to, the router creates round corners, and the chisel will finish the square corner job once the rest of the mortise has been routed out.
How Do I Know What Size Router Bit To Get?
Router bits come in various sizes, but according to Home Depot recommendations, you’ll want to have a ½ inch router bit. Experienced woodworkers find that size to be more stable and offer better performance than smaller bits. There are some jobs for which a smaller bit might be preferable, but for our purposes in creating a hinge mortise, the ½ inch router bit is recommended.
Many router bits use bearing guides to route a pattern with precision. The guides do exactly what the name implies – guides the bit along the pattern, in this case, the hinge template. For our purposes, then, we’re referring to the template pattern for the hinge mortise.
The bearing bit then simply needs to be set to the proper depth. Your hinge dimension will tell you what that depth is, and remember that we want the hinge to lay flush with the door’s surface and the jamb.
You’ll be using a plunge router for this task, too. As the name implies, a plunge router is one that “plunges” into the wood being routed. The depth of the plunge can be set, and in our case, we want that depth to be set to the dimension of the hinge we’re using to ensure the hinge lies flush with the door’s wood surface jamb.
Here’s a helpful video to offer some tips on notching a hinge mortise with a router.
Can You Use a Trim Router For Door Hinges?
If you watched that video, you heard the woodworker say he prefers to use a trim router for hinge mortises. He likes its light weight and ease of control and finds it does the job well.
Many routers can be purchased with both fixed and plunge bases. A trim router with a plunge base obviates the necessity of having to tip the router into the wood, and the guide gives smooth and evenly aligned sides to the mortise. This would be especially convenient for a piece of inlay
But, the short of it is a trim router for door hinges is a good choice.
Final Thoughts on Routers, Bits, and Hinge Mortises
Perfect fit, proper depth and flush alignment with door and jamb surface all lead to a door that hangs well and properly closes with no gap. This is the desired outcome.
In addition to the tools mentioned in this article, you’ll want, as always, to have your safety glasses handy, as pieces of wood and dust will fly up and about. A mask covering the nose and mouth is highly recommended as well.
It’s not a big job. The video mentioned in this article presents helpful tips on the process of creating a proper mortise. Routers are not especially expensive, and most avid woodworkers and hobbyists consider them to be essential tools.
There are many brands to choose from, and knowledgeable salespeople can help you choose the best model for your task and skill level. There’s great satisfaction from routing a mortise, installing the hinges, and hanging your own cabinet doors.