Casio BP-100 (2) – Restoration

The Casio BP-100 came out in the early 1990s and was one of Casio’s boldest health-focused watches. It used small metal sensors on the front and caseback to let the wearer check blood pressure and pulse. For its time, it was a very ambitious design and quickly became a talking piece among collectors.

The watch I found was in poor condition. The strap was missing, the battery was dead, and the case had a lot of grime, especially around the sensor pads. The acrylic crystal was badly scratched and had lost its clarity.

One detail gave me motivation to start the project. The yellow text “BLOOD PRESSURE MONITOR” on the case front was still visible. Many BP-100s lose this text completely with age, so I wanted to preserve it and make the watch look as close to original as possible.

What was the condition of the watch at the start?

When the Casio BP-100 arrived, it was in rough shape:

• No strap – the watch could not be worn.
• Dead battery – the module showed no signs of life.
• Heavy grime – especially on the sensor pads and caseback.
• Acrylic crystal scratched – surface was cloudy and full of marks.
• Yellow “BLOOD PRESSURE MONITOR” text still visible – a rare detail that made this watch worth saving.

Overall, the watch looked tired and unused for years. But the case was not cracked, the buttons were still in place, and the original lettering was intact. That gave me a good reason to start the restoration.

How did the restoration process go?

Step 1: Disassembly

I started by taking the watch apart. The module was removed from the case, and I separated all parts for cleaning. Keeping parts in order is important, especially with older Casios, so nothing gets lost.

Step 2: Cleaning the case and sensors

The resin case was washed with warm water, mild soap, and a soft brush. This removed years of dirt. The metal front sensor plate and the caseback had lots of grime and light scratches. I used a fine abrasive pad to clean them. This made the metal look fresh again and also removed small marks.

Step 3: Crystal sanding and polishing

The acrylic crystal was in the worst shape. I sanded it in stages: starting with 1000-grit sandpaper, then moving up step by step until 7000-grit. After sanding, I polished it with paste using a hand polisher. This brought the crystal back to clarity and made the display easy to read again.

Step 4: Battery and strap

I installed a new battery, and the watch powered up without any problems. Finding an original BP-100 strap today is almost impossible. When you see one, the price is usually very high. To solve this, I matched the watch with a strap from the Casio SDB-500W, which fits perfectly and keeps the watch comfortable and wearable.

The result of the restoration

After all the work, the Casio BP-100 looked and worked like a proper collector’s piece again. The crystal was clear, the case and sensor pads were clean, and the new strap fit perfectly. Seeing the display shine through a polished crystal made the watch feel alive again.

The best part for me was that the yellow text “BLOOD PRESSURE MONITOR” was still visible. On most BP-100s this detail fades away completely, so saving it made the project extra satisfying.

This was not the hardest restoration I’ve done, but it was very rewarding. The BP-100 is a piece of Casio history from the time when they were experimenting with medical technology on the wrist. Now this watch is ready to be worn and enjoyed again.

👉 What do you think? Would you like to own one of Casio’s “medical” watches like the BP-100? Or do you prefer to collect the more classic databanks and gadget models?