Changing the hands of a watch can have a significant impact on its overall appearance, affecting both the styling and legibility. However, the process of replacing watch hands can be tricky, as there are several factors to consider to ensure a successful modification. In this comprehensive guide, we’ll explore the ins and outs of replacing watch hands, from understanding the sizing requirements to the tools needed and the proper techniques to avoid damaging your timepiece.
Understanding Watch Hand Sizing
The first and most crucial step in replacing watch hands is ensuring that the new set will fit your watch’s movement. Watch hands are not standardized, and their size is determined by two measurements: the diameter of the hole at the hub of the hand and the length of the hand. These measurements are typically given in millimeters, with the diameter of the center hole measured to the nearest tenth of a millimeter (or hundredth of a millimeter for seconds hands) and the length measured to the nearest whole or half millimeter.
To determine the correct size of hands for your watch, you can use a hand sizing gauge or calipers to measure the posts sticking up from the movement. It’s important to note that the length of the hand is measured from the tip or end of the hand to the center of the hole at the hub, not to the end opposite the tip. This means that the specified length of the hand ordered will be shorter than the full physical dimensions of the hand.
Choosing the Right Hand Lengths
Once you have determined the correct size of hands for your watch, you’ll need to carefully select the lengths of the hour, minute, and seconds hands. A good general rule of thumb is:
- The tip of the hour hand should just reach or touch the inner edges of the hour markers.
- The tip of the minute hand should reach either the outside of the hour markers or the inside of the minute markers.
- The tip of the seconds hand should reach at least the same as the minute hand or to the outside of any seconds markers.
These guidelines will help ensure that your watch is easily legible at a glance and visually appealing. If the hour and minute hands are too similar in length, it may be difficult to read the time quickly, especially in low light conditions. If the minute hand is too short, you may not be able to gauge the time as precisely as desired. For the same reason, a seconds hand should reach as far outward as possible to clearly differentiate the seconds as they elapse.
Precautions should be taken if the dial of your watch has raised or applied index markers, as hands that are too long can touch or catch on the markers, causing the watch to stop or scratch the markers as they pass by.
Removing the Old Hands
Before installing the new hands, you’ll need to remove the old ones. There are several methods for removing watch hands, each with its own pros and cons. The most common methods are using Presto-type tools and hand levers. Regardless of the method used, it’s good practice to protect the dial while removing the hands, either with a specific dial protector or a small section of plastic film.
When using a Presto tool, place one finger (usually the index finger) on top of the tool to steady it, and position the center guide on top of the hands to be removed. Gently squeeze the bowed arms of the tool inward and guide the blades to the underside of the lowest hand, taking care not to touch the dial. As you continue to squeeze, the tool will close under the hands, and the white posts will lower onto the dial (the reason for using the dial protector) and gently lift the hands off the movement.
Hand levers are simpler to use. Place the tips under the hands and up to the center posts, then gently lower the opposite ends to lift the hands up.
Installing the New Hands
When it comes time to install the new hands, the exact process and order can vary based on the complications of the movement, but the technique remains more or less the same. The tools used to install the hands come in a variety of types, but the most common are the watch installation tool and the hand-pressed tool.
To install the new hands, place the movement under the tool and position the hands at the midnight position. Press down on the watch installation tool to secure the hour hand, followed by the minute and second hands. Be extra careful with the second hand, as there is a small pin that must align correctly with the middle of the movement. If this isn’t aligned properly and you press down, you could potentially damage your watch.
After installing the hands, carefully bend them to ensure they aren’t touching each other or the crystal.
Replacing watch hands can be a rewarding and cost-effective way to give your timepiece a fresh new look. However, it’s important to approach the task with care and attention to detail to avoid damaging your watch. If you’re unsure about your ability to replace the hands yourself, it’s always best to consult with a professional watchmaker to ensure the job is done correctly.