How to: A Starter Guide to Seiko Watch Modding

Seiko introduced its first dive watches 55 years ago, and has never looked back. The brand has a rich history of firsts in the field and the Seiko name is practically synonymous with high quality, bulletproof divers.

More recently, Seiko dive watches have inspired a new generation of watch enthusiasts to customize their Seiko divers with a seemingly endless and growing array of options available in the aftermarket.

Seiko sub mod for saleThe rise in Seiko modding is attributed to a couple of factors: the quality and design aesthetics of Seiko divers are a big selling point for starters. That, combined with low cost but high quality movements (sold by Seiko Instruments to the trade) and the advent of aftermarket parts suppliers servicing this demand, means that you can now pretty much build any watch you'd like based on an aftermarket Seiko case-and-movement combinations out there. 

What is Seiko Modding? 

Watch modding or Seiko modding is short for “modifying”. It is the process of changing your watch’s aesthetics, and at times, mechanics, from the original factory design to your preferred one.

Watch modding is a relaxing, meditative hobby that provides a lot of room for growth and going deep. 
Seiko Hulk Mod for sale

What is the best watch for modding? 

There are a number of watches you can modify, most all of them are in the lower end of the market where mistakes while learning aren't so costly. But the 800 pound gorilla in watch modding is the Seiko SKX007 platform, followed closely by Seiko Turtles. The options available for these case types make Seiko a great choice of entrée into the world of watch modding. 

Here’s why:

  • Modding involves mixing and matching of bezels, dials, and multiple other aesthetic and mechanical features, and thus, should be done on a base watch that offers a broad range of custom modding options. Seiko has all other watch brands licked in this regard (by a country mile). 
  • Aftermarket suppliers have been quick to recognize the growth in Seiko mod parts for sale and responded with a range of high quality parts built to fit both OEM Seiko watches and aftermarket production cases. 
  • Seiko watches are excellent value for money. They're easy to service, easy to regulate, and darn near indestructible. And if you do destroy a movement, a new one costs less than a night out at the movies. 
  • From start to finish, depending on choices you make along the way, you can build a high quality, dream watch from the ground up for $300-$500 out of pocket. Or conduct a partial mod, like swapping a bezel insert or crystal, for $30-$60. Sometimes a little change is all that's required to make a big difference! 

What are Different Modding Options Available? 

If you are new to the world of modding Seikos, then you might find getting started a bit overwhelming. However, don’t worry, the Seiko modding community is here to help you out and share advice. 

To start with modding, you first have to decide the modification path that you want to take. This could be either of the two below:

Complete Modification

As you would have gathered from the name, the complete modification of your Seiko watch would involve an entire (or nearly entire) overhaul. Sounds daunting. Rest assured it's well within your capabilities to do this!

Seiko SKX007 double dome sapphire crystal with blue AR

Start with your chosen Seiko model — we recommend starting with an SKX007 mod starter kit like this one — and let your imagination take over. This gets you the basics in one kit:

From there, you've got the basics in hand and it's now time to style your watch to your specifications. You'll need to choose its bezel, bezel insert, chapter ring, dial, hands and more.

Want your Seiko diver to sport an Omega-style dial and a Rolex-style bezel insert? Go for it!

Subtle Modification

This option involves minor changes without switching multiple parts. Common mods include a crystal swap, or changing out the bezel and insert. These are relatively simple operations. A bezel swap can even be done without any specialty tools, but tread lightly otherwise you risk scratching up your case trying to pry the bezel off. 

Even though these modifications are subtle, they have a massive impact on the overall look of the watch. We even keep a few bezel-and-insert combos on hand to swap with our daily wearers to refresh the look of a base dial-and-hands combo we like. Keeps things fresh and won't break the bank!

What tools are required for Seiko Modding? 

Seiko Modding is a slightly technical process, and thus, requires certain tools for support. As you can imagine, the range in both price and quality of tools is quite large, as you might imagine. You can start with cheap kits from China (available all over eBay and Amazon) and use those for your first few mods. But if you really get the bug, you'll want to upgrade some strategic parts of your toolkit to Swiss or higher-end tools that can speed up your work and ensure fewer errors, hassles, and scratches compared to their cheap counterparts.  

Watch Modding Tool Kit Essentials:

  • Finger cots or gloves to keep grease off of your delicate watch parts
  • Case back remover
  • Crystal press (used for seating both crystals and bezels)
  • Jeweler's putty (or Rodico as it's referred to by watch makers)
  • Dust blower
  • Toothpicks
  • Screwdrivers for watch repair, ideally anti-magnetic (magnets + watches = bad news)
  • Tweezers
  • Gorilla or masking tape
  • A workstation with an appropriate setting for tiny parts 
  • Hand setting tools
  • Hand remover
  • Movement holder
  • Springbar tool 

The good news is you can get a more-than-serviceable watch tool kit for under $80 that will last you through a good portion of your learning curve. I've got recommendations for "strategic upgrades" in the toolkit that will GREATLY enhance your watch modding experience and I'll post more on tools and recommendations in an upcoming post. 

How to mod a Seiko SKX007

The best way to learn how to mod a watch is to check out resources on YouTube, like tutorials and videos from Eric at LumeShot. I also recommend lurking around watch modding communities like r/seikomods on Reddit; they're a little more forgiving when you're starting out than more hardcore horological communities. 

Either way, you'll open up a world of possibilities with members of the modding community who are generally happy to share their passion for modding, impart modding wisdom, and share how they've successfully solved challenges others are likely facing. 

Let's walk through the basics of modding a Seiko, so you can identify the steps when watching modding videos on YouTube to learn the craft. Remember, these are just basic steps for hand, crystal, and dial replacement, and might require further additions based on your modding plans.

  • Use the quick-release tab to remove the watch strap. If your timepiece doesn’t have it, then use a spring bar tool.
  • Use the watch case opener to open your watch’s case.
  • Identify the small release lever on your movement, and use a toothpick to remove the crown and stem by pushing on the lever. Don't shove anything metal into your watch and wear finger cots to prevent contaminating the movement with oils from your skin.
  • Gently remove the watch’s movement by using a toothpick to pry up the movement, being careful not to touch the mainspring or any sensitive bits. Once the movement has been lifted to a slight angle and is free from the pressure keeping it in the case, you can place the watch on a pad and tap it out of the case. 
  • Removing the hands requires a hand-remover tool and a piece of plastic to act as a scratch-protector for the dial, which is quite delicate. Rotate the crown so all the watch hands are aligned in one direction. Now, place the hour hand on the 12H marker and hold it down via tweezers. Similarly, place the minute hand and the second's hand.
  • Now, for watch dial’s replacement, remove the dial by finding one of the two slots in the movement holder to lift the dial up -- it's held in place with dial feet, using only pressure.
  • Next, place your desired dial on the plastic bracket such that its legs are aligned with the holes, and fix gently. Some aftermarket dials require you to remove extra dial feet. Simple procedure done with some fingernail clippers. Don't be afraid!
  • For crystal replacement, remove the crystal using a crystal press with gentle pressure -- it will pop out easily. To replace the crystal, you'll need to fist fit the case with a crystal gasket to ensure water resistance. Use the crystal press to gently press the new crystal into place, working slowly to ensure a flat deposition of the crystal in the case. 
  • At this stage, I recommend testing for water resistance. More on that in a future post about tools and methods. 
  • Lastly, replace the movement, reattach the crown, stem, and strap, tighten up your case back and your personalized Seiko watch will be ready to roll!

I've found that the Seiko modding community offers an easy "on ramp" with a lot of support. You can also go very deep with the skills you build as you modify more and more watches. Once you get Seiko mods down, you'll open up endless possibilities that can lead you into creating watches with Swiss movements, cases, dials and more -- the possibilities are truly endless, making this one hobby you'd be had pressed to out grow.  

I want someone to mod my Seiko!

If you have a specific Seiko watch design on your mind but aren’t keen on modding it on your own, we recommend reaching out to a modder whose work you like (we offer modding services, custom builds, parts and more at NXTSKO). The modder might already have one similar to your taste in his or her collection, or will modify your watch as per your requirement. The majority of them have years of experience, and thus, won’t disappoint you!

Written by Jim Calhoun