It will come as no surprise to any watch enthusiast, that if you have an interest in learning more about the mechanics of a watch, then the Seiko’s 7s26 based watches are a perfect place to start. A movement with a pedigree going back over two decades, used in the most tried and true models of Seiko’s, such as the SKX models and Seiko 5 series, has developed a huge community of modders.
Early in my journey building the PNW001, I was forced to overcome my fear of “screwing up” a watch movement when I dived headfirst into the Sellita SW200 that I used for the project. Armed with only the basics of tools, and all the wrong ones in retrospect, and knowledge of watchmaking from a vintage copy of Watches Adjustment & Repair by F.J. Camm, I learned as I went. All the meanwhile, in the back of my mind I had this voice saying,
“Why didn’t you just start out with modding something like a Seiko?”
But in hindsight, it set me down the horological path that I am on and helped me understand what makes these horological machines really tick. Unlike Swiss movements, parts for the 7s26 are easily accessible in the United States, and much more affordable than their Swiss counterparts. When Seiko made the 7s26, the successor to or arguable upgrade from the prior 7002, you can tell that they had serviceability and simplicity in mind.
Take these accessible OEM parts plus third-party modding parts, and you have a weekend project. You can mod something like an SKX easily. How easily? If you are new in the #watchfam, the forums can range with opinions. The way I see it, it depends on the level of risk you are comfortable learning from and how deep you really want to go down the modding rabbit hole. Something outside the case? Relatively low risk. However, the deeper you mod, be prepared that this project watch could become a sacrifice to the horological learning gods. Bear in mind, that a slip of a screwdriver to a balance spring may lead you to have to purchase an entire replacement OEM movement. With that said, the 7s26 movement can be found for around $60.
Starting off with an SKX007K1, you have an investment of, on the upper end, $200 USD (at the time of writing this), and only slightly cheaper if you can find one on the secondhand market, as they are often snatched up by modders.
Level of modding based on risk (i.e. courage), patience, tools, and skill
----The Basic Modding Risk Zone----
Something simple and great if you want to just commemorate an occasion. It is a subtle way to mod your watch and make it personal, and make any watch a commemorative one. Blank case-backs can be engraved simply, as Paul Newman’s “Drive Carefully Me”, or etched with a custom vector art design. My thanks to Bay Engraving in Bellingham for working with me on making this illustration an engraving reality.
A ‘tool watch’ is just that; a tool. Even if you are not a diver, that bezel can be a useful tool with the right bezel. Changing out the insert to either something more your style, or adding additional functionality, like a 12hr bezel, can modify this tool to fit your life. So, make a pot of tea for yourself and relax. While you let your tea steep, also pour some of that fresh hot water into a small container and steep your bezel too. This will loosen the adhesive on the back of the insert to allow you to scrape it off and minimize bending of the insert.
The ring around the insert can be popped off with some gaffers tape on the lugs (to prevent scratching), and a case knife. Be aware that there is a click spring with two tangs that stick up to catch the underside of the bezel, which can easily break if you get your knife caught underneath it and the bezel when you push the knife under.
-----Elevated Modding Risk Zone----
When popping off the hands, protect that dial! Yes, some hand pullers look to have anti scratch feet on them that press down; don’t trust them. Use a dial protector or a poly-bag to protect the dial and use even, vertical force to take off the hands. To put new hands on, look for a hand press to make life a little easier for yourself.
With the hands off, the dial is compression fitted (like much of this movement) into two holes. Take your tweezers to the gaps at the side of the movement top plate and dial then gently let the dial slide upwards.
-----Advanced Modding Risk Zone----
Crystal & Chapter ring
A crystal press will be required to get a new crystal and gasket installed. I have not done this on the SKX (but I have on another watch). I would encourage novice modders at this point to look for a watchmaker with a water resistance machine. In my mind, if you have gone this far, and you have the movement and everything out, why not have a watchmaker check your work on the case and verify that you’re still in spec for water resistance. It is also a great opportunity to get to know your local watch maker.
Day & Date wheels
A C-shaped snap, two plates and four screws hold the date and day wheels together. Something I learned in this process is to keep an eye on the alignment when putting in the new wheels, as you want to make sure that the day date will look straight in the dial aperture when reassembled.
What tools might be helpful?
- Screw driver set with extra blades that can be sharpened
- Case back opener (wrench)
- Case knife
- Crystal press
- Watch case holder
- Movement holder(s)
- Gasket lube
- A hand blower (or if you are a photographer, your Giotto rocket)
- Anti-Magnetic tweezers
- Dial protection (or poly-sheet)
- Hand pullers
- Containers to keep your parts
- Bergeon Rodico (puddy)
- Watch cushion pad
- Seiko technical sheet (Seiko link) (7S26C_36C PDF)
Mod Part Vendors:
- Crystaltimes Horology
- One Second Closer
- Yobokies (email them to get pricing and purchasing info)
Working on a Seiko and reading from people who are more knowledgeable than I in watchmaking. Big shout outs to:
- Nick of Orion Watches- https://orionwatch.com/how-to-mod-your-seiko/
- Nicholas Hacko- http://www.clockmaker.com.au/diy_seiko_7s26
Links to the SKX and watch modding
- Li Wang – Worn and Wound – Watch Modding 101
- Jack Forster – Hodinkee – The Seiko SKX007 Diving Watch