How to Stress-Test a Seiko Mod Before Using It As Your Daily Wear

After weeks of planning and sourcing parts, completing a mod and finally getting the watch on the wrist feels very satisfying. You’d be tempted to take a few wristshots and post it online, a proud achievement to share with your watch enthusiast peers. But before your newly-assembled build can be called your new daily beater, it’s worth putting it through a couple different tests just to make sure that it doesn’t look right, but functions right as well.

It may look perfectly executed on the outside while small, unseen issues can actually show up after a few days of wear. It could be a gasket sitting just a little bit askew, or the movement running a lot faster or slower than the expected tolerances. Perhaps even a single particle of dust that everyone says is nothing to mind, but very much annoys you every time you look at it. 

They may sound like small matters, but it’s easier to fix now than later. Think of it like the final quality check that bigger watch brands do with their top-selling watches. After closing up the caseback, these are simple steps you can do to get your watch into a true go anywhere, do anything timepiece.

The Basics

Before worrying about the internals, spend a few minutes looking at the overall watch. Is the crystal sitting evenly with no visible gaps at the edges? Does the bezel rotate fully and with consistent clicks? Does the crown go through each position smoothly and securely, and for screw-down crowns, does it thread all the way in when closing it up? Do the bracelet fit snugly to the lugs?

You’d also want to pay close attention to the face of your new Seiko mod. As mentioned, dust or fingerprints that you missed with rodico on the inside of the crystal can be a real pet peeve. The chapter ring might sit slightly off-center, causing misalignment issues with the dial markers. Take note of these details so you can correct them all in one go. Let’s hope you’ll not need to open it up a third time.

Once you’re happy with the appearance of the watch, it’s time to move onto the movement. Ideally, this should have been fully tested before the first assembly even started, but some issues only become more obvious once everything has already been put together. To test, wind the movement, set the time, cycle through the day and date functions, and make sure that the hacking function works. And don’t forget the backside too: the rotor should spin freely if you move the watch around, and should not be catching against the caseback at any point.

Checking Water Resistance

Let’s get this out of the way first, if the watch you’re building is meant only for desk diving and not actual deep sea diving, then your standard 50m water resistance rating should be enough to protect against splashes and the occasional soaking. But if you think you need the full 200m of WR, then double-checking the water resistance before and after the mod can help save your watch from water-logging.

A pressure tester can be too costly, but these are generally available at your local watchmaker so you can bring it there instead of getting one for just one or two builds. It’s a quick test that gives you peace of mind if you’re planning on taking your watch for a swim.

For hobbyists, a basic moisture check you can do is checking for condensation when you move between cool and warm environments. If you notice any fogging, then moisture could already be present inside the case. If it remains dry, it’s not a surefire indicator but it’s certainly a good start until you can bring your watch in for an actual pressure test.

Inspecting the Movement

You don’t need chronometer-level accuracy for a watch to be useful, but it should be predictable. If it loses or gains a few seconds per day, it should be consistent so you know when you’d need to adjust it to get accurate time. If it behaves erratically, and especially if it functions outside Seiko’s advertised accuracy of -20 / +40 seconds per day, you may want to get it regulated.

For this, you would need a timegrapher, which is another piece of equipment that might be too expensive to get when you’re just starting out with Seiko mods. Your local watchmaker should have this handy. This tool measures beat rate, amplitude, and beat error, which tells you how a movement is performing and why. For example, a low amplitude can mean lubrication issues, while a high beat error suggests that the lever isn’t centered properly.

Magnetism is another thing worth checking, since we’re pretty much surrounded by magnets in our everyday life. Magnetization can turn a perfectly fine movement into something that keeps terrible time without any obvious explanation. Fortunately, demagnetizers can be cheap and easy to use. If your new build starts behaving strangely, try to rule out magnetization first before taking it to a watchmaker.

One last thing to check would be the power reserve. Fully wind the movement and let it run until it stops, which should be around 40 hours on your standard NH movement. If it stops significantly earlier, it might be worth looking into.

Real-World Use

After all the visual inspections and tool diagnostics, there’s one thing left to do: wear the watch for a few days as part of your normal routine. Pay attention to how the watch feels on your wrist, particularly if your strap fits properly and is comfortable to wear for long periods of time. Check if the strap is secure, and that there are no sharp edges on the bracelet’s body links.

Also check how easy (or hard) it is to read the dial in different lighting conditions. And how’s the lume at night? Is it a strong, uniform glow between the different components, or do you notice that it glows a bit weak or discharges completely after just a couple hours?

Wrap Up

When the watch looks clean, runs consistently and reliably, stays free of moisture, and feels comfy after a few days of regular wear, then you can finally call your build a success and wear it with confidence.

And if something doesn’t pass the test, that’s alright! Constant improvement is one of the hallmarks of being a Seiko modder, and you can look at it as a natural part of the hobby - an added challenge so you can tinker a bit more with your watch before using it.

Though sometimes, issues arise not because of a missed step, but because of genuine part defects that require a replacement. How do you avoid this? Get your parts from a reputable source, like namokiMODS! As one of the top choices by professionals, you can be sure that your ordered parts are of high quality so you can build a watch you’ll be proud to wear. Our helpful team is also ready to assist you if you encounter any issues with our units. Whether you need a case as the base for your next mod, or just a couple gaskets to maintain the water resistance of your watch, you can get it here.

Happy modding!