In the wooden display case that you can watch how I made in the previous posts, the door does not need anything to keep it closed, since it is horizontal and so it works as the lid of a trunk. But in a display case we usually put things that are valuable, at least for us, so installing a small full mortise lock, like those used in wooden trunks, is not superfluous.
How to install a full mortise cabinet lock
We can install a mortise lock using a drill with a wood drill bit, along with a little chisel work, but it is a somewhat cumbersome method. And using a plunge router, a small lock with key and other hardware for cabinets, desks, drawers or a display case can be installed in a way that seems much simpler to me. So I bought a small full mortise lock at my favorite hardware store. And now, taking advantage of the fact that I have a straight router bit with a diameter equal to the width of the lock plates, and I also have another straight router bit with a diameter only slightly larger than the thickness of the metal case of the lock mechanism, we are going to see how to install the full mortise lock with the help of the plunge router.
With the straight cutter of diameter equal to the width of the plate installed in the router, I push the router until the cutter touches the table and lock it. aqui I adjust the depth stop to the thickness of the sheet metal, and later I will adjust the side guide to mill the box exactly in the area where I want to install the lock.
But first I must mark the area with the help of the ruler, the square and the lock itself. I measure and mark the center of the strip, center the lock making sure I won’t mill over the glass of the display case, and mark the width and length of the plate.
Now all I have to do is adjust the side guide of the milling machine so that the milling cutter coincides exactly between the marks of the width of the lock plate. With the milling machine unlocked, I can mill between the marks that give me the length of the sheet metal with the peace of mind that the depth stop allows me to mill a box to the perfect depth for the sheet metal. I won’t touch the side guide adjustment until I mill on the window, which is slightly wider than the display case.
With this first milling already done, it is easy to mark the width of the metal box that houses the lock mechanism. Although I actually mark a little more on each side, as my straight cutter is not long enough to mill the full depth needed without the cutter shaft, which is wider than the cutter itself, reaching the wood.
So that this does not hinder the milling process, I first use an 8mm milling cutter, equal to the milling cutter axis, to mill a box a few mm deep. In this way the shaft of the thinner cutter will no longer bump into the wood and I can make the box to the desired depth, previously set with the depth stop of the milling machine. Since I want this box perfectly centered in the milling I did for the sheet metal, the side guide adjustment is the same, so I didn’t touch it.
Once I check that the lock fits perfectly, I measure the position where the key hole is, mark the position on the display case and with a drill bit drill a couple of holes and join them together. I place the lock and make sure that the lead goes in and operates the lock mechanism smoothly.
Now I place the plate that will go in the window face down in the box I milled. And with the screws facing upwards. I put the window in place and press it against the screws, so that the screws dig into the window a little bit. And I screw them all the way in, because that way, with the window in place, I can check to see if the lock will work.
I remove the window again, mark the perimeter of the sheet metal with a pencil and unscrew it. And with the same milling cutter that I used for the plate that is attached to the lock mechanism and the same procedure, I am going to mill a rebate. This rabbet serves as a box for the plywood with the hitch pin that goes on the window. But this time I do have to readjust the position of the side guide before milling. In addition, with the box already milled, I drill a light hole to accommodate the riveting that has the hitch pin on the back of the sheet metal.
I can now screw the lock to the showcase frame, and the plate with the hitch pin to the window. I put the window back in place and put the trim for the key hole. As you will see in the video, this trim gave me a couple of problems, as the screws do not fit as well as I would like. And if I were to put some more decorative screws I have to take into account that if they are too long they would bump into the metal box of the mechanism and would not fit at all.
Anyway, apart from some small problems, you can see that with the help of a milling machine it is very easy to install a mortise lock.
So, after installing the mortise hinges and the lock for this display case, all that was left was to install a retaining bar to prevent the door from opening too far.