Worried about installing a mortise lock

[Tom Jones III]

I'm building a new entry door and in researching door knobs it appears that the mortise style locksets are superior. I would like to install one in my new door, but everyone seems to comment about how hard they are to install. The reputation seems to be that an amateur could never do it and a professional will have a hard time.

I'm new to the whole thing but it seems like people are having trouble making a 4" deep mortise. Is that the entire problem or is there something else? The style is 5.25" wide so I should have enough room. I have not glued up the door yet so that may make it even easier to set the lock, would you set the lock before or after the door is glued up? Also, should I attempt to reuse the existing bolt hole in the door frame?

[george wilson]

We made 4" deep mortises in Williamsburg often. I recommend you drill a string of 4" deep holes across the mortise-to-be,and chisel out the waste. If a pro would have a hard time doing it,how did all those doors ever get installed on site? There is a special bent chisel called a swan neck,that is bent at the end to help lever chips out,though I never used one.

[Craig McCormick]

I have been watching another tradesman on our current jobsite mortise 9 doors yesterday with a spade bit and a chisel. He used his trim router for the recess that the face plate sits in. He made it look pretty easy. No jigs or guides.

Craig McCormick

[David Keller NC]

"The reputation seems to be that an amateur could never do it and a professional will have a hard time."

Horsehockey. Full mortise door locks are pretty easy, as locks go. One of the reasons is that you can just set the lock in the door in your shop, then hang it, and use the door lock bolt to indent the door frame where the strike plate will go.

And yeah, no question that it's easier to cut a stopped dado for your door lock if your door stile is to be a laminated, two piece design. But simply cutting the mortise isn't that big of a deal, though if it were mine, I would definitely do it with drill bit and a chisel instead of a router and a jig. A drill bit and a chisel do things slowly, so a mistake is not usually disastrous.

With a router, one slip and you've ruined a lot of work. So if you're going this route, highly advisable to mortise the lock in one stile and the hinge mortises in the other stile before you glue the door up. That way, if you make a slip, you're only out the one piece of wood. Otherwise, you're replacing the entire door - that'd be a severe drag. :(

[Doug Miller 303]

Tom,

I just did this about a year ago on a 1 1/4" screen door that I had built.

I put the door in some dogs to hold it upright, and that made my life much easier. You could do this on the bench prior to glue up if you know the exact location, or haven't cut the hole in the jamb yet. Key word here is exact, that thing has to line up, or you have just wasted lots of time and effort.

I jointed a couple scraps of 2x4 and clamped them to the door, flush with the edge. This made a nice large flat surface for the drill guide I was using.

Then I used my cordless drill, with a forstner bit and went to town. Just be very careful, take your time, and don't screw up. There are no second chances here.

After that, I used a chisel. And I chiseled, and chiseled, and chiseled, etc., etc. This part took FOREVER. Test fit the lock often to make sure things are working out.

You can do this, you'll just have to be very patient. (I think more patience than Job would be in order here.) I had to walk away from the job, and go do something else quite often.

I never did figure out how many hours I had in that one, and don't really want to know. If you are doing this for a customer, make sure you charge at least $50,000........yer gonna need it for the therapy bills. Just kidding.

If you need more help, I'm here for ya.

Edit: I would recommend using a Baldwin lockset with a Medeco cylinder. Your locksmith can help you with compatibility.

Doug

[Kent Parker]

Tom,

Great looking door!

Another method would involve the use of a plunge router to cut the beginnings of the mortice. This would allow for precisley cut sides to provide a bearing surface for your chisels. I did a similar cut when making pieces for a mortice and tenon fence.

The first photo shows the stop blocks clamped to limit the travel of the router which defines to mortice length.

The next shot shows the router placement with an altered Bosch router guide. The extra blocks accomodate the thickness of the stock but more importantly provide greater bearing on the stock and stabilize the router

The third photo shows an additional block clamped in place to help guide the chisel for it final cut. With your mortice cut you use a variety of drill bits (forstner, spade, ect) to get rid of the central "meat" and then gradually cut outwards with your ultra sharp chisels towards the sharp and accurate router cut.

Cheers,
Kent