Make my hole bigger!

January 26, 2007 6:20 PM

How do I make a deadbolt hole in a door wider?

I bought a brand new fancy expensive deadbolt lock for my new apartment, a Medeco Maxum to be exact. The problem is, the old hole for an old deadbolt which I never had the key for is 1/2" too small for the new mechanism. I have a semi-powerful cordless drill, and the appropriate hole bits to drill out the lock, but I cant get any sort of leverage or pull to be able to drill through the wood sandwiched on either side with metal. The drill bit is for metal/wood and is similar to this, where there is a large hole bit, and a smaller bit inside to initially drill and pull the rest of the bit through the wall straight.

Now I ask you, metafilter, what's the best way to widen this hole? My ideas thus far have been:
- Fill the hole with bondo or similar and see if I can drill it out like that.
- Screw a bit of wood in a T shape with the bottom of the T going through the hole, and then nail/screwing the top of the T to the outside of the door and drilling into that.

Thats all I got. Is there a better/proven way to do this? Should I fill and forget about this old hole? There's already a second lock, and a doorknob, and the old deadbolt is in a good place, anywhere else and it would be awkward.

posted by Mach5 to home & garden (7 comments total)

IANAC but I've used your Bondo technique.
My filler of choice was Fixall, it's cheaper.
I predrilled with a bit smaller than the saw's pilot bit.
Got that pilot hole as square as possible.
Worked in from both sides and didn't overheat the saw.
Cake.
posted by Fins at 6:59 PM on January 26, 2007

Get a piece of wood about 1/4-1/2" thick.
Use your bit and make a hole in it.
Clamp it onto the door centering it on your existing hole.
Drill your new, bigger hole.
posted by lee at 6:59 PM on January 26, 2007

Easiest would be to take the door off its hinges and use a drill press. Either borrow a smallish portable one or cart the door to a large heavy floor model.
posted by MonkeySaltedNuts at 7:14 PM on January 26, 2007

lee is basically right, but you will want two boards. The problem is that the center bit of your hole saw is what guides it so you will need something for it to bite into on the other side once you have sawn through the board on the drill side of the door. Here are pictures.
posted by caddis at 7:45 PM on January 26, 2007

Getting a door up onto and level with a drill press would be a colossal pain in the butt. lee has the trick. caddis, once the hole saw cuts through the clamped-on scrap on the near site, the hole it's made will guide it through just fine. It'll splinter hell out of the exit side, though, that's why you clamp a scrap on that side too. Also, to keep the clamp from marking up the door :)
posted by nicwolff at 10:54 PM on January 26, 2007

I agree
posted by caddis at 11:28 PM on January 26, 2007

I had this problem a few months ago and ended up using a chisel and a package of Dremel sanding bits to widen the hole.

For most hardware the hole doesn't actually have to be circular, it just needs to have arcs at the top and bottom and enough room for the lock mechanism to move.
posted by tkolar at 10:22 AM on January 27, 2007