u/CandidBench3601

Put together a buying guide comparing the four movements that come up most in mod builds. Here's the TL;DR:

NH35A — 21,600 bph · +10/-15 s/day · $28–50 · Best for: beginners

Miyota 9015 — 28,800 bph · +/-10 s/day · $55–90 · Best for: intermediate builds

ETA 2824-2 — 28,800 bph · +/-4–12 s/day · $130–220 · Best for: premium/collector

Sellita SW200 — 28,800 bph · +/-5–12 s/day · $90–145 · Best for: Swiss quality without the ETA premium

All four have hacking and hand-winding. The jump from NH35 to Miyota 9015 is the most cost-effective accuracy upgrade. ETA vs Sellita is mostly a brand preference call — the movements are near-identical.

Full breakdown (origin, power reserve, jewel count, recommended skill level, where to buy) here:

👉 https://tokimodder.com/en/blog/guia-compra-movimientos-seiko-mod

What are you running in your current build?

This comes up constantly in modding communities and I never see a straight answer, so here's my take after using both.

Both are solid Japanese movements. Both fit the same case diameter. But they're not interchangeable, and picking the wrong one can create headaches with dial and hand compatibility.

The short version:

- NH35 is cheaper (30-50€), has a massive parts ecosystem, and is the default for SKX/SRPD-based mods. The downside: no hack, no hand winding, and a visible tick on the seconds hand.

- Miyota 9015 costs roughly double, but you get hack, hand winding, a much smoother seconds sweep (28,800 vph vs 21,600), and it's noticeably thinner (4mm vs 5.85mm). Accuracy out of the box is also better.

The compatibility trap nobody warns you about:

Dials and hands are NOT cross-compatible between the two. The dial feet positions differ, and the minute hand tube size is different (0.7mm on NH35, 0.6mm on Miyota 9015). Always check before buying parts.

My honest recommendation: start with the NH35. The parts availability and community support make your first builds much easier. Once you're comfortable with the process, the Miyota 9015 is a natural upgrade for more serious projects.

Full comparison with specs table, compatibility breakdown, and where to buy: https://tokimodder.com/en/blog/nh35-vs-miyota-9015

Which do you run in your mods? Any strong opinions either way?

Quick question for the community: how many of you actually go through a proper waterproofing process after a mod?

I ask because I've seen a lot of beautiful builds here, but waterproofing barely gets mentioned. It's honestly one of the steps that can make or break a mod — not aesthetically, but literally.

Here's the short version of what I do:

-Replace every o-ring, no exceptions. Old ones deform during disassembly even if they look fine.

-Clean all o-ring channels with IPA before installing anything.

-Silicone grease on every o-ring — thin film, not a glob.

-Crystal sealed correctly for the mount type (rubber gasket, bezel pressure, or UV adhesive).

- Caseback closed with even pressure.

-Crown screwed in. Always. This is the one that kills movements.

For testing without a pressure tester: cold water soak for 30 minutes, dry completely, then check for condensation under the crystal near a warm light. Never hot water — thermal expansion can force the seals.

I wrote a detailed guide on this with a full materials list, step-by-step for each seal point, and the most common mistakes: https://tokimodder.com/en/blog/impermeabilizar-seiko-mod

Curious — do you use a pressure tester? And has anyone here actually had water damage on a mod? What happened?

Quick question for the community: how many of you actually go through a proper waterproofing process after a mod?

I ask because I've seen a lot of beautiful builds here, but waterproofing barely gets mentioned. It's honestly one of the steps that can make or break a mod — not aesthetically, but literally.

---

Here's the short version of what I do:

- Replace every o-ring, no exceptions. Old ones deform during disassembly even if they look fine.

- Clean all o-ring channels with IPA before installing anything.

- Silicone grease on every o-ring — thin film, not a glob.

- Crystal sealed correctly for the mount type (rubber gasket, bezel pressure, or UV adhesive).

- Caseback closed with even pressure.

- Crown screwed in. Always. This is the one that kills movements.

For testing without a pressure tester: cold water soak for 30 minutes, dry completely, then check for condensation under the crystal near a warm light. Never hot water — thermal expansion can force the seals.

---

I wrote a detailed guide on this with a full materials list, step-by-step for each seal point, and the most common mistakes: https://tokimodder.com/en/blog/impermeabilizar-seiko-mod

Curious — do you use a pressure tester? And has anyone here actually had water damage on a mod? What happened?

Quick question for the community: how many of you actually go through a proper waterproofing process after a mod?

I ask because I've seen a lot of beautiful builds here, but waterproofing barely gets mentioned. It's honestly one of the steps that can make or break a mod — not aesthetically, but literally.

---

Here's the short version of what I do:

- Replace every o-ring, no exceptions. Old ones deform during disassembly even if they look fine.

- Clean all o-ring channels with IPA before installing anything.

- Silicone grease on every o-ring — thin film, not a glob.

- Crystal sealed correctly for the mount type (rubber gasket, bezel pressure, or UV adhesive).

- Caseback closed with even pressure.

- Crown screwed in. Always. This is the one that kills movements.

For testing without a pressure tester: cold water soak for 30 minutes, dry completely, then check for condensation under the crystal near a warm light. Never hot water — thermal expansion can force the seals.

---

I wrote a detailed guide on this with a full materials list, step-by-step for each seal point, and the most common mistakes: https://tokimodder.com/en/blog/impermeabilizar-seiko-mod

Curious — do you use a pressure tester? And has anyone here actually had water damage on a mod? What happened?

Let me be honest about something: I've handled a real Submariner. It's an incredible object. The finishing, the weight, the way the bezel clicks — nothing at this price point replicates that.

But I also watched the owner spend the entire dinner with his wrist under the table. That's not a watch. That's anxiety on a strap.

So I built a Sub homage instead. NH35 inside, ceramic bezel insert, sapphire crystal, Mercedes hands, black sunburst dial. Total cost: just under $250. It lives on my wrist every single day and I don't think about it once.

Here's what I learned building it — because the Submariner build has a few specific traps that other mods don't:

\*\*The bezel insert material is not optional.\*\* There are aluminium inserts and ceramic inserts. Aluminium is cheaper and will fade, scratch, and look worn within a year of daily use. A ceramic insert costs a few dollars more, is essentially scratch-proof, and is what makes the difference between a build that ages well and one that starts looking rough by year two. Get the ceramic. Non-negotiable for a daily wearer.

\*\*Mercedes hands are the whole point of the Submariner aesthetic — but hand installation is where most first builds go wrong.\*\* The hour hand on a Submariner homage is the iconic arrow-shaped Mercedes hand. It's also the hardest of the three hands to set correctly because of its weight distribution. Too much pressure and you'll bend it; too little and it won't seat properly and will come loose. If this is your first build, buy a spare set of hands before you start. They're cheap. You will probably ruin one.

\*\*The crown position changes everything about dial compatibility.\*\* The original SKX007 has a crown at 4 o'clock. Most aftermarket Submariner cases use a 3 o'clock crown. If you're sourcing a dial from a donor SKX, the day wheel on an NH36 will sit behind the 4 o'clock position and show as clipped through the date window at 3 o'clock. Either use a date-only NH35 with a date-window dial, or source a dial specifically designed for a 3 o'clock crown case. Getting this wrong means a finished watch with the date display partially blocked.

\*\*Double-domed sapphire crystal makes a bigger visual difference than people expect.\*\* The Submariner's distinctive look partly comes from its domed crystal catching light at angles. A flat sapphire is functional and scratch-resistant, but a double-domed one adds that depth and visual warmth that makes the watch feel closer to the real thing. Worth the small price difference.

\*\*The lug width on Submariner cases is typically 22mm — not 20mm.\*\* This catches people out when sourcing straps or bracelets. Standard 20mm straps won't fit properly and will either be too loose or require adapters. Check your case specs before you buy a rubber dive strap or a jubilee-style bracelet to go with it.

Full parts list, movement options, and step-by-step build breakdown here:

👉 https://tokimodder.com/en/blog/seiko-mod-submariner-guia

What configuration are you running on your Sub build? Black dial + black bezel is the classic but I've been tempted by a blue "Bluesy" setup lately.

When I started modding Seiko watches, the movement question nearly paralyzed me. NH35, NH36, NH34, NH38, NH70... everyone throws these numbers around like they're obvious, but nobody really explained why you'd pick one over another for a specific build.

After a lot of trial and error (and one very bent hand), I put together a guide that breaks it all down in a way that made sense to me. The key things I wish someone had told me earlier:

The NH35 is the default workhorse for a reason — massive parts ecosystem, forgiving for beginners, cheap enough that you don't panic if something goes wrong

The NH36 adds day-date functionality but almost nothing else changes, so it's a no-brainer upgrade if you want that complication

The NH34 is genuinely a game-changer for GMT builds — before it existed, dual time zone on a budget was basically impossible

The NH38 solves the annoying "ghost date click" problem on no-date builds — cleaner crown action, better dial symmetry

The NH70/71 are only worth it if you actually want the skeleton aesthetic, not just because it looks cool in listings

One thing that took me forever to understand: all these movements are essentially built on the same 7S26 base caliber from the SKX era, so they're drop-in compatible with almost anything. The one exception is the NH34, where the hand height sits slightly higher — so you need to think about case depth before committing.

I wrote up a full guide with specs, use cases, and some notes on avoiding clone movements (yes, fakes exist, no they're not worth saving $15 over):

👉 https://tokimodder.com/en/blog/guia-movimientos-seiko-mod

Happy to answer questions in the comments — what movement are you running in your current build?

The Nautilus is a $35,000 watch. The secondary market has pushed it past $100,000 at peak. Most of us will never own one, and honestly, for daily wear, the anxiety alone would ruin it.

So I built one. Or rather — a Seikonaut. Same silhouette, NH35 inside, sapphire crystal, integrated bracelet. Total cost under $300. And it's become the watch I reach for most.

But I made several avoidable mistakes getting there, and I want to save you the same pain.

The case thickness is everything and nobody talks about it enough. The real Nautilus 5711 is 8.3mm thick. That's impossibly slim for an NH movement — you're not going to match it. But there's a massive difference between a well-proportioned 11-12mm Nautilus case and the chunky 13-14mm versions flooding AliExpress. The thick ones look wrong on the wrist and won't go under a shirt cuff. Measure before you buy. This single decision determines whether your build looks like a serious watch or a toy.

The horizontal embossed dial is non-negotiable for the look. The Nautilus's signature "clous de Paris" horizontal texture is what makes it instantly recognisable. A sunburst dial in a Nautilus case just looks like a generic sports watch. The texture is the whole point. The 30.8mm size is the standard for most Nautilus cases — double-check your case specs before ordering.

\*\*NH35 vs NH38 here is actually worth thinking about.\*\* If you want a clean dateless dial — which works beautifully in a Nautilus build — the NH38 removes the ghost click problem you get with an NH35 behind a no-date dial. Worthwhile upgrade if you're going for a minimalist look. If you want day/date, NH36 is your movement.

\*\*The bracelet is not interchangeable with SKX parts.\*\* New builders constantly make this mistake. The Nautilus case has a unique integrated lug shape — standard SKX007 bracelets don't fit. You need to source a bracelet specifically made for your case. Get this wrong and you're waiting for a second delivery before you can wear the thing.

\*\*The integrated bracelet finish matters as much as the case.\*\* The brushed-and-polished combination is what gives the real Nautilus its visual depth. A Nautilus case with a flat brushed bracelet looks unfinished. Look for a bracelet with alternating brushed and polished links — it's the detail that closes the gap between "mod" and "watch."

I put together a full breakdown — parts list, sizing guide, movement options, and where the build can go wrong — here:

👉 https://tokimodder.com/en/blog/seiko-mod-nautilus-guia

What finish did you go with on your Seikonaut? Steel, two-tone, or something else?