Cumaru Key Hanger (February 1st 2018)

One of the hardest changes after getting married and moving to the city was remembering to lock the door to our apartment. I'm from a rural area where people leave their keys in their car and the door to their house unlocked. It's not unusual to see cars idling in the post office parking lot while the owner is inside. After a number of times where my wife would discover the door had been unlocked all night, I decided to do something about it.

Mechanical Iris Engagement Ring Box


I had a length of scrap Cumaru decking liberated from the dumpster of a job I was working on and decided to make a nice wooden hanger with a magnet that would stick to our metal door. This stuff is seriously hard and dense. It has interlocking grain and splinters easily. Not the nicest material to work, but it will look pretty when it's oiled.

For the magnet, I needed something strong to hold the weight of my keys. I didn't have any hard drive magnets handy, but I did have an old speaker magnet. I broke off a small chunk and cut two pieces of pallet strapping to concentrate the magnetic flux.

Mechanical Iris Engagement Ring Box


I sandwiched the magnet with the two pieces of strapping, stuck it in the mortised out hole, and covered it with some left over epoxy. I also epoxied the peg into the main piece.

Mechanical Iris Engagement Ring Box


After the epoxy had cured, I belt sanded the back flat. It's crazy how just two thin pieces of metal increase the power of the magnet. It's actually a bit too strong and it sticks to the door with a resounding clank!

Mechanical Iris Engagement Ring Box


Here you can see the metal plates a bit better.

Mechanical Iris Engagement Ring Box


And the front side with the peg I whittled out.

Mechanical Iris Engagement Ring Box


I oiled it up with mineral oil and stuck it right beside the deadbolt. Yes... The sign was pretty much ineffective. I haven't forgotten to lock the door once after a month of use!