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-   -   retrofit modern doorknobs to old keyhole doors? (

BostonBarbara 07-01-2007 09:44 AM

retrofit modern doorknobs to old keyhole doors?
We purchased modern doorknobs for our 1880 colonial not realizing that ALL of the doors in the house have keyholes, and the knobs do not fit. All of the old knobs are worn out (the square shafts are not long square) and we would prefer using the more modern knobs.

Is there anyway to retrofit these? Also, we can't return the knobs, we bought them a year ago online.


BLZBUB 02-06-2008 11:21 AM

You've got a complicated problem. I can only imagine that by "keyhole", you've got what's called a mortise lock. That is to say, there is a large, rectangular assembly that incorporates both the latch mechanism, and the lock mechanism. The "square shafts" you refer to are called spindles, and it sounds like they need to be replaced. A good locksmith should be able to help. You'll probably need to shop this around, so be patient. Try to remove the entire mortise assembly by unscrewing it from the door's edge. You'll also need to remove the knobs and spindle and any screws through the faces of the door to free the mortise lock and slide it out. Take this whole assembly, along with your new knobs, to a locksmith and see if he has spindles of the appropriate length that will fit both the mortise lock and the knobs. There are adapter sleeves if the proper spindle for the mortise lock is smaller than what the knobs require. If it's larger, well, hope it's not larger. Try this on ONE DOOR ONLY to see if it's possible. Good Luck.

Hack 02-06-2008 12:44 PM

Repairing them is the best way to go. Keep the old lock sets with the old house. I have rebuilt several of mine by looking in antique stores. Sometimes they'll have a box full of old mortise lock parts and complete sets.

If you're really determined to swap for new, you'd be best off staying with a mortise lock. Otherwise you're rebuilding the whole mortise area to fill in the gaps, etc.

You can get brand new mortise locks that look old or new, depending on what you're looking for...

Check these:

guyod 02-07-2008 07:28 AM

Yours door are just too narrow to use a modern door knob. Try to selling them on ebay or replace your doors...

If the spindles are just bad you can just take them out and replace them. they are sold at big box stores you can get new knobs while your at it all pretty cheap.

glennjanie 02-10-2008 09:44 PM

Welcome Barbara:
I'm picturing a square lockset that is screwed to the inner surface of the door and a spindle that runs through the door to operate the lock.
Check to make sure your door is at least 1 3/8" thick. If it is you can remove the old lockset, Tightly clamp a piece of 3/4" board to each side of the door, drill through the block according to the setback specified for the new lock (the new lockset should include a template of cardboard) remove the blocks and drill for the latch, drill the door frame to match and follow the instructions with the new lockset.

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