24 hour wall clock

This mod turns a helpless 12h analog clock into a dashing 12-at-the-top 24h analog clock.


Part Price
Wall Clock (30cm/~12” diameter) $20 from Target
printed copy of the clock face 24h_clock_v2.1_face.ps or 24h_clock_v2.2.pdf 75¢ from Kinkos
24h clock movement $13 for movement, hands and shipping from Klockit.com
Spraymount (had some on hand)

Total cost: ~$33.75

white Target clock For the wall clock, I picked up one that matched our kitchen’s decor. This is a white, generic 12” clock from Target, (SKU 490651513545). This particular clock’s face diameter is 28.3cm, so I adjusted the clock face printout for it.


Examining the host clock

clock with the frame off

The clock with the metal border removed.

clock with the hands off

The clock with the hands and movement removed.

12h clock movement

The removed 12h clock movement. It turns out that these quartz movements are remarkably standardized in their dimensions. The 24h movement I got is not very different in size from this one.

white mask

A white paper mask cut to cover up the old 12h numbers. This will prevent them from showing through, even if the new face is printed on thin paper.

white mask

Yup. You can’t really see the numbers.

face printout

I had the face printed at Kinkos on their oversized printer, as it was just a bit larger than 11x17” with the dotted line around it. It wasn’t the best print job and the paper was thinner than I wanted, but it seems to get the job done. Next time: design it so it will definitely fit on 11x17”, as everyone can print onto that size.

face installed

Both hands and face installed.

I decided to use spraymount (a type of weak glue that comes in a spray can, usually used for movable fixtures) to join the clock face printout to the white mask. This reinforced the face so it was rigid, while masking out the old numbers. Due to this rigidity, I didn’t need to affix it to the clock body permanently. As is, the screw that holds in the movement also holds on the face.

The hand installation was straightforward. I had to use two of the rubber gaskets that sit between the clock movement and the clock body, as the 24h movement’s post was longer than the original movement’s post (it was touching the glass).

completed clock


clock hanging on the wall

I think it looks pretty nice hanging in our kitchen.

I may attempt to make the numbers a little larger, as there was more room in the face than I originally anticipated. I left the face loosely installed in case I ever decide to do this.

full photo gallery