Re-attach the caseback on a water-resistant watch

I had to replace the battery on my watch last week. I ran into a snag and figured out a good solution, which I thought I’d share here.

  1. Pry the back off – easy.
  2. Get the battery out – easy.
  3. Read the tiny number on the battery – harder.  I couldn’t find a magnifying glass, but I managed to read it with my phone camera’s zoom.
  4. Order a new battery online – easy.

The battery came in the mail a few days later. I thought it would take two minutes to install and I’d be done. But I couldn’t get the caseback on. It’s a water-resistant watch, and the rubber gasket made it too tight to press closed with my hands.

I worked at the watch & jewelry repair counter JC Penney as a teenager. I know a watch press is the right tool for the job, but I don’t spend money on professional tools for occasional personal use. I looked to youtube for advice but didn’t find anything too useful. I found one video saying that all you need is some newspaper underneath (to protect the crystal) and a big tool (like a wrench) for some leverage when pressing down on the back. Tried that, but I still couldn’t get enough force to close it.

I decided to try a clamp. I grabbed some scrap wood—big enough to cover the crystal and the back, small enough to avoid pressing on the strap lugs—and a C clamp, and started tightening the clamp. But it kept slipping off center as I tightened it. I could’ve cut out a wooden circle to hold it (like the die for a watch press), but I didn’t feel like spending that much time on it, so I tried a few more times to carefully center the clamp and slowly tighten it.

On one of those attempts, just as it was starting to slip a tiny bit, I realized that a second clamp would help me put pressure on the other side and re-center it. After a little more progress tightening both clamps, I needed a third one. A couple more turns on each clamp got me the satisfying click of the watch back snapping into place. With a bit of nervous anticipation, I took the clamps off and checked my work. I was relieved to see the crystal was still intact and the watch was still ticking.

Disclaimer: If you have a valuable watch, you probably should buy the right tools or pay a professional.