How To Patch A Hinge Plate Mortise

Repairing the hinge mortise when removing a door

In this video, Gary Streigler, of Craftsman Builders, demonstrates a simple jobsite remodeling skill: filling the hinge mortise after removing a door. This is part of a door replacement for a laundry room: from outswing to bifold. 

EDITED TRANSCRIPT:

So, here’s the problem I’m dealing with.

We’ve got a tight space here — laundry room’s right behind this wall — and we need a wide enough door opening to get a washer and dryer in. That means a fairly big door. Originally, if the door swung in, it would hit everything. So they decided to swing it out. Well, when it swings out, it comes across and hits this jamb right here. It just doesn’t work.

Now, if I had plenty of wall space, I’d probably go with a barn-style door. In new construction, maybe even a pocket door. But pocket doors come with their own challenges — no electrical boxes, no plumbing in that cavity. That’s actually why barn-style doors got so popular. They solve some of those issues. But in this case, there’s no room for a barn door to slide in either direction.

So we’re installing a bifold barn-style setup. But before we do that, I’ve got to patch these old hinge mortises in the jamb. That’s what this is about.

Remove the door stop with a prybar

Sometimes on a project, you’ve got to start left to go right. For me, that meant removing this door stop first. There’s no way I’m going to patch this cleanly with that stop in place.

I’m using one of my favorite little tools — just a simple flat pry bar. These used to be called hive tools. It’s thin, sharp on the end, and they’re worth their weight in gold. You can get one just about anywhere tools are sold for 10 or 15 bucks. I use it for trim removal with the least amount of damage possible.

First thing I do is cut the caulk joint on both sides — because if your painter did his job, everything’s caulked tight. Then I slide that flat bar in and gently pry the door stop off. Works great for baseboard too. Minimal damage, which is the goal.

Cut a clean recess in the hinge mortise

We’d already patched the lower hinge spots. For these, I’m using a fairly thick patch piece — just under a quarter inch. I want something I can glue and nail without worrying about it splitting.

I made a simple plywood jig. I cut the pattern using a Whiteside ½-inch pattern bit. The bearing on that bit rides along the notch in my jig and removes material about a quarter inch deep.

I position the jig so the new mortise area is clearly bigger than the original hinge. That way I don’t have to be perfect lining it up. I tack the jig down with a couple of 21-gauge, inch-and-a-quarter brads — just enough so it won’t move.

The key when routing is keeping the base of the router flush to the template and starting without the bit touching wood. Then I move counterclockwise around the pattern.

Once I’m done, I pop the template off. Removing that door stop earlier? That made this about 100% easier.

I wiggle the brads back and forth until they snap below the surface. That’s just the cleanest way to deal with them.

Square the corners after routing

Because I used a ½-inch round bit, the corners of the routed area are rounded. So I take a chisel and square those up. It’s not much material, but if I skip that step, the patch won’t seat properly.

My chisel was dull — so I did what I call my “jobsite sharpening trick” and hit it with the belt sander. Not textbook sharpening, but it works when you’re on site.

Fit the patch

Now I test-fit the patch piece.

It’s tight — which is what I want — but maybe just a hair too tight. So I make a couple of passes with my block plane on the back side. I put a pretty aggressive angle on it, but I make sure not to go all the way to the face. I don’t want to mess up that front edge.

Once it fits just right — maybe just a buzz thick — I glue it in with Titebond and shoot a few 21-gauge brads. Those tiny brads have just enough head to give me some pulling power.

After the glue sets, I sand it down. We’ve been hitting it with 40-grit to knock it flush. Here’s my rule:

"If I can’t feel it, you’re not going to see it once it’s painted."

The painter may come back with 100 or 120 grit and finesse it a little more, but as carpenters, if we leave it so you can’t feel the patch, we’ve done our job.

This is a great way to patch hinge mortises if you’re removing a door or changing hardware and don’t want to replace the entire jamb. Once it’s painted, you’ll never know there was a hinge there. And in this case, it’s just one step in a bigger project — replacing this door with a bifold barn-style door system that actually works in this tight space.