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branchandrootThis was a sufficient pain in the butt I figured someone else might benefit from the invective overview.
A mortise lockset is one of those old style locks that's got a rectangular case that fits into a hollowed out pocket inside the door. They generally open with a bit key (see also, skeleton key) and tend to be quite old and cranky.
The first advice you will see, if you look up how to replace or convert a mortise lockset is "get a newer mortise lockset". This is because it's a royal pain to convert a door for a cylinder doorknob lock. As long as you know what you need ahead of time, though, it's mostly just time consuming.
Needed:
two pieces of wood the same width/length/depth as the mortise case minus the height of your new doorknob latch
wood putty
wood glue
spare cardboard
2-1/8 in hole saw
a strong drill
two 1/4 inch pieces of plywood, though 1/2 will do in a pinch, about three or four inches square
at least two clamps
construction paper
masking tape
pencil (and a spare)
a small chisel
mallet
screwdriver(s)
measuring tape
straight edge, rather a long one
Take out the mortise lockset and all its attendant hardware, doing as little damage to the door as possible; this may involve some ingenuity if it was tightly fitted.
Slather the two pieces of wood the same size as the lockset with wood glue and insert them into the pocket, leaving a channel free for the new latch (line up your new latch with the existing doorknob hole to make this as simple as possible). This will likely involve a lot of mess, and I find it helps to support the upper piece with rolled up cardboard to hold everything in place while it dries. And drips. You may wish to stuff the bottom piece with kleenex or similar to stop the drips and keep in as much glue as possible. The whole point is to restore as much structural integrity to the door as possible.
Sleep on it while that dries. Do not try to saw it before 24 hours are up, honestly.
Cut construction paper in four and tape all around the existing doorknob hole, though not over the space you will have to cut. Insert the new latch barrel into the free channel. Put the spare pencil or the rolled cardboard into the space the new doorknob shaft will go. Draw crosshairs on the paper that center on the pencil. (You may wish to do this on both sides, but I found one side to be sufficient.) Take out the latch.
Take the two 4x4 pieces of plywood and put them over the hole on either side of the door and clamp them. Tight. This is to guide the hole saw and prevent splintering. Draw the crosshairs on these, too, and mark the center clearly.
Now the fun part. See, you won't be able to cut the new hole in one go, not with the plywood in the way, but you need the plywood to guide the hole saw because of the existing hole. So center your pilot bit on the crosshairs and start drilling. When the saw goes through the plywood and a bit into the door, go ahead and clear the plywood disk from the saw. Now that you have a cut started, your saw should cut straight in; go back and drill some more. You will most likely have to clear the saw again, once you cut through the interior bits you stuffed the pocket with. Once you're all the way through the door, go ahead and stop, no need to go through the second piece of plywood. Rejoice, and sweep up all the sawdust. You're almost there.
Install the doorknob lock!
Now look at the doorjamb. You will almost certainly need to chisel out new space for the new latchplate, so go ahead and do that (marking carefully where the latch is when the door is closed). Put in the latch plate.
Now you have a working doorknob lock, but you also have big, ugly pieces of raw wood ends and chewed-up door jamb, and quite likely a hole further down the door where the keyhole used to be. This is what the wood putty is for. Stuff all open space thoroughly with wood putty.
Sleep on it again.
Sand down your wood putty plugs and paint them to match the rest of the door.
Done!
I hope this helps someone, because figuring out all of this on the fly was not a recipe for a relaxing and peaceable weekend.
A mortise lockset is one of those old style locks that's got a rectangular case that fits into a hollowed out pocket inside the door. They generally open with a bit key (see also, skeleton key) and tend to be quite old and cranky.
The first advice you will see, if you look up how to replace or convert a mortise lockset is "get a newer mortise lockset". This is because it's a royal pain to convert a door for a cylinder doorknob lock. As long as you know what you need ahead of time, though, it's mostly just time consuming.
Needed:
two pieces of wood the same width/length/depth as the mortise case minus the height of your new doorknob latch
wood putty
wood glue
spare cardboard
2-1/8 in hole saw
a strong drill
two 1/4 inch pieces of plywood, though 1/2 will do in a pinch, about three or four inches square
at least two clamps
construction paper
masking tape
pencil (and a spare)
a small chisel
mallet
screwdriver(s)
measuring tape
straight edge, rather a long one
Take out the mortise lockset and all its attendant hardware, doing as little damage to the door as possible; this may involve some ingenuity if it was tightly fitted.
Slather the two pieces of wood the same size as the lockset with wood glue and insert them into the pocket, leaving a channel free for the new latch (line up your new latch with the existing doorknob hole to make this as simple as possible). This will likely involve a lot of mess, and I find it helps to support the upper piece with rolled up cardboard to hold everything in place while it dries. And drips. You may wish to stuff the bottom piece with kleenex or similar to stop the drips and keep in as much glue as possible. The whole point is to restore as much structural integrity to the door as possible.
Sleep on it while that dries. Do not try to saw it before 24 hours are up, honestly.
Cut construction paper in four and tape all around the existing doorknob hole, though not over the space you will have to cut. Insert the new latch barrel into the free channel. Put the spare pencil or the rolled cardboard into the space the new doorknob shaft will go. Draw crosshairs on the paper that center on the pencil. (You may wish to do this on both sides, but I found one side to be sufficient.) Take out the latch.
Take the two 4x4 pieces of plywood and put them over the hole on either side of the door and clamp them. Tight. This is to guide the hole saw and prevent splintering. Draw the crosshairs on these, too, and mark the center clearly.
Now the fun part. See, you won't be able to cut the new hole in one go, not with the plywood in the way, but you need the plywood to guide the hole saw because of the existing hole. So center your pilot bit on the crosshairs and start drilling. When the saw goes through the plywood and a bit into the door, go ahead and clear the plywood disk from the saw. Now that you have a cut started, your saw should cut straight in; go back and drill some more. You will most likely have to clear the saw again, once you cut through the interior bits you stuffed the pocket with. Once you're all the way through the door, go ahead and stop, no need to go through the second piece of plywood. Rejoice, and sweep up all the sawdust. You're almost there.
Install the doorknob lock!
Now look at the doorjamb. You will almost certainly need to chisel out new space for the new latchplate, so go ahead and do that (marking carefully where the latch is when the door is closed). Put in the latch plate.
Now you have a working doorknob lock, but you also have big, ugly pieces of raw wood ends and chewed-up door jamb, and quite likely a hole further down the door where the keyhole used to be. This is what the wood putty is for. Stuff all open space thoroughly with wood putty.
Sleep on it again.
Sand down your wood putty plugs and paint them to match the rest of the door.
Done!
I hope this helps someone, because figuring out all of this on the fly was not a recipe for a relaxing and peaceable weekend.
Thanks
Date: 2011-12-21 09:50 pm (UTC)thanks
Re: Thanks
Date: 2011-12-21 09:56 pm (UTC)