One aspect of the modern trend towards increasingly larger wristwatches is that the availability of spare parts has yet to catch up. Particularly for brands that do not have the capacity in place or simply choose not to furnish these parts.

Recently, I had a client who needed a new 44mm crystal for his watch. None of the suppliers I contacted had one available – in either mineral or sapphire crystal. The largest was 42mm. It is possible to get a mineral crystal cut to size for a somewhat reasonable price, but the cost of cutting a sapphire crystal to that size quickly runs up into the hundreds of dollars.

The cost of obtaining a sapphire crystal at that scale – even before cutting – ruled it out as a replacement. Mineral crystal, on the other hand, wasn’t ideal as it scratches relatively easily compared to sapphire. Straight glass is even less scratch resistant and is more prone to breakage. Plastic would better be able to stand up to a hard knock, but it is very easy to scratch. This unusual circumstance called for an unusual solution and, thanks to a breakthrough material resurrected by the smartphone industry, we were able to deliver.

The solution came in a material known as Gorilla Glass. Developed by Corning in the 1960s, the new material failed to find its way into any viable product at the time and production was soon sidelined by the company. Fast forward 50 years and a viable market has since appeared in the form of the iPhone and, later, the iPad along with nearly every other touch tablet and smartphone that has debuted since. Steve Jobs’ biographer, Walter Isaacson, details much of the previously untold backstory around the rebirth of Gorilla Glass in the official biography of Jobs that was released a few months ago. Having just finished reading the biography myself the same week that the need for this oversize crystal arose, the unique properties and relative affordability of Gorilla Glass were still fresh on my mind and, with a few phone calls, we were able to make it happen. Gorilla Glass is comparable in strength and scratch resistance to sapphire, but boasts the ductility and impact resistance of plastic. It’s a truly remarkable material and, in this case, proved to be a truly remarkable solution.

To learn more about Gorilla Glass, check out this video on YouTube or hop on over to the official Gorilla Glass website for a full listing of characteristics.

One of the stranger items on last year’s list of stocking stuffers for watchmakers was a mouldable, silicone rubber known as Sugru. I mentioned then that I’ve used it to improve the ergonomics of some the tools I use. One of those tools is a hand tool designed for installing and removing pushers in Tissot’s T Touch line of watches. For years I found the standard levered handle uncomfortable to use repetitively or on pushers that are a particularly tightly fit. So, when I first heard of Sugru, improving the ergonomics of this handle was one of the first applications I thought of applying it to.

Before & After

The red handle on the following tool, from a different watch brand, is nearly identical in construction to the original handle on the tool from Tissot. In fact, the two tools are so similar in construction, I am convinced that both were likely manufactured by the same Swiss tooling company. This tool is one I haven’t improved the ergonomics of yet, so it offers an idea of what the “before” picture of the Tissot tool would have been had I taken one.

I applied two packages of orange Sugru over top of the red part of the handle, increasing its thickness, and then sculpted it to conform comfortably to my fingers when gripped. Here is the result:

I am really pleased with the way it worked out and now find the tool much more comfortable to use than it was previously.

Some Useful Tips

If you decide to use Sugru to improve the ergonomics of any of your own tools, here are a few tips I think are worth sharing based on my experience working with it:

1. Sugru comes in a specially sealed package and begins to cure as soon as you open it. I found it lost much of its plasticity within 30-40 minutes of opening it. So it’s important to have a good idea of what you’re aiming to sculpt with it before tearing a package open.
2. Although it cures to the touch within 24 hours or so, I’d recommend letting the Sugru set for 72 hours before applying heavy pressure in areas where the product is built up more than a millimeter or so. I used the tool to install some pushers a little over a day after forming the handle and noticed that it caused the Sugru in the thicker areas of the handle to deform somewhat from the way I had originally sculpted them.
3. Bits of Sugru will tend to stick to your fingers as you work it. To achieve the smooth finish I did on the handle, I routinely dipped my fingers in warm, soapy water as I shaped the final surface.
4. Sugru has an expiry date. Don’t order more than you think you’ll use over the course of a few months.