The Ultimate Beginner's Guide to Watch Modding and Repair in Canada

Welcome to the Rabbit Hole

There is a moment in every watch collector's journey when simply buying a new piece isn't enough anymore. You look at a factory dial and think, "That would look incredible with different hands," or you get tired of paying a jeweler $20 just to swap a battery or resize a bracelet.

Welcome to the world of watch DIY and modding.

Taking control of your own collection—whether that means performing basic maintenance or building a custom automatic dive watch completely from scratch—is the most rewarding part of this hobby.

At North Repair Supply, our philosophy is simple: you do not need a $30,000 Swiss engineering degree or a bench full of wildly expensive European tools to get started. You just need the right gear, a bit of patience, and a willingness to learn. This guide is your permanent roadmap to building your skills, your toolkit, and your first custom watch.

The Modder’s Glossary: Know Your Parts

Before you tear down a watch, you need to speak the language. The aftermarket is massive, and ordering the wrong size part will stop a build in its tracks. Here are the core components you will be working with:

• The Movement (The Engine): The mechanical or quartz heartbeat of the watch.
• The Dial (The Face): The metal plate displaying the hours. Mod dials often come with small metal "feet" on the back that plug directly into the movement.
• The Handset: The hour, minute, and second hands. These must be sized precisely to the movement's pinions.
• The Chapter Ring: The angled inner ring circling the dial, often printed with minute markers.
• The Bezel & Insert: The rotating outer ring on dive watches, and the colored aluminum or ceramic insert that snaps into it.
• The Crystal: The glass. Upgrading from standard mineral glass to scratch-resistant sapphire is one of the most popular beginner mods.

Starting Small: Basic Maintenance & Quick Wins

You don't need to tear down a mechanical movement on day one. The best way to build confidence at the bench is by mastering the fundamental repairs that keep your collection running smoothly.

Before you attempt a custom build, you should know how to change a strap without scratching the lugs, properly size a metal bracelet, and safely open a seized caseback.

Read our full guide on The 3 Watch Repairs Every Collector Should Do Themselves here.

Don't Ignore Your Quartz Watches

Many beginners assume a dead quartz watch just needs a battery, and if that doesn't work, the watch is ruined. In reality, quartz watches have physical gear trains that need attention, and leaving a dead battery inside can cause catastrophic acid leaks. Learning how to properly diagnose and swap a dead quartz movement is a mandatory bench skill.

Read our deep dive: Do Quartz Watches Need Service?

Building Your First Workbench: Essential Tools

The biggest mistake beginners make is either buying the cheapest, flimsiest toolkit on Amazon (which bends and breaks on the first use) or spending $500 on professional Swiss brands before they even know if they like the hobby.

A smart builder curates a utilitarian bench. We bench-test everything in our own shop before selling it to ensure it actually works. Your starter kit should include:

• Precision Screwdrivers: To handle delicate bracelet screws and movement bridges without shearing the metal.
• A Safe Case Holder: A high-density plastic block with articulating nylon pins (never bare metal) to lock the watch down securely without crushing the case.
• An XL Jaxa Wrench: A heavy-duty, 3-prong wrench capable of expanding up to 55mm to grip the wide casebacks of modern dive watches.
• Quality Lubrication Tools: Basic, bench-tested oiling pins that deliver microscopic drops of oil exactly where they need to go.

The Anatomy of a Build: Movements, Dials, and Hands

When you are ready to graduate from basic repairs to full custom builds, you need to understand the ecosystem. The modern modding world revolves almost entirely around the legendary Seiko NH35 (and NH36) automatic movement.

Because the NH35 is an open-source workhorse, a massive global aftermarket has sprung up around it. You can source custom dials, specialized hands, and heavy-duty sapphire crystals that all snap together like high-precision LEGOs.

The Big Three: NH35 vs. NH36 vs. NH34

If you are building a custom watch today, you are almost certainly using an unbranded Seiko automatic movement from the "NH" family. They are affordable, bulletproof, and fit into thousands of aftermarket cases.

But ordering the wrong one will completely ruin your dial and hand choices. Here is exactly how to tell them apart:

• The NH35 (The Standard): This is the undisputed king of watch modding. It features standard hour, minute, and sweeping second hands, plus a Date wheel (usually at the 3 o'clock or 6 o'clock position). If you are building a classic dive watch like a Submariner homage, this is your engine.
• The NH36 (The Day/Date): Mechanically identical to the NH35, but it adds a Day of the week wheel right next to the date. Builder Warning: If you buy an NH36, you absolutely must buy a dial with a wider "Day/Date" window cut out of it. If you put a standard NH35 date-only dial over an NH36 movement, you will hide the day wheel entirely and the dial might not sit flat.
• The NH34 (The GMT): This is the newest heavyweight in the modding scene. It adds a fourth hand (the GMT hand) that rotates once every 24 hours, allowing you to track a second time zone. Builder Warning: Because it has a fourth hand stacked on the center pinion, the NH34 requires slightly taller hand clearance. You usually need a case specifically designed for an NH34 or a domed sapphire crystal so the second hand doesn't scrape against the glass. The center hole of the dial must also be slightly wider (2.88mm) to accommodate the thicker pinion.

The Culture of Modding: Homages vs. Fakes

As you dive into this hobby, you will quickly encounter the "Seikonaut" and "Seikoak" builds—watches modified to look like six-figure luxury pieces, but powered by Seiko engines.

This brings up a massive debate in the watch world. Is building a custom homage a legitimate expression of horology, or does it cross the line into counterfeiting? Understanding the intent behind a build, the respect for intellectual property, and the difference between a fake and a custom hot-rod is an important part of joining the community.

Read our full breakdown on The Ethics of Seiko Modding and Custom Builds.

Sourcing Parts: The Canadian Advantage

The most frustrating part of modding has always been the wait. Historically, builders had to order parts from overseas dropshippers, wait four weeks for the package to clear customs, and pray the parts actually fit when they arrived.

We built North Repair Supply to solve that problem. We source high-quality, utilitarian gear, filter out the junk, and ship directly out of Calgary, Alberta. That means you get your tools in days, not weeks, so you can keep your momentum going at the bench.