What is a Hydro Mod? An Oil-Filled Quartz Watch (If You Really Want To Do That to a Watch)

I don't usually modify my watches apart from sometimes changing the strap or bracelet or bezel. But some guys really like to do some very impressive "mods" to customize their watches. One of the most unusual things they do is called a Hydro Mod. This is where they fill the watch case with some kind of oil to change the overall look of the watch face and possibly enhance the watch's water resistance. In this video I'll talk about Hydro Mods without actually doing one. But here are some links to videos where other guys are showing you what they did and how they did it.
• Oil Filling a Watch:Ho...
• How To - Hydro Mod The...
• Hydro-Mod Tutorial
• [Modified Casio] Hydro...
• Video
Among the most popular watches which are good candidates for this modification are the Casio Duro MDV106 and the Casio MRW-200H. These watches are relatively inexpensive so, even if this modification doesn't go well and the watch is a complete loss, you haven't wasted a lot of money. If you are interested in trying a Hydro Mod on your own watch I encourage you to keep watching those other videos. And if you've already done this to your watch, feel free to leave a comment about how it went for you.

[@jpsrandom6943]

The way the watch reflects the light is different, the way it pops against the glass and the slight change of density are very cool imo. Any way, the mod scene is very cool, people always show something different and help each other in constructive ways, I see no harm in that. Cool video, very informative.

[@wirdy1]

Many yrs ago I had a watch by hyperbar that was liquid filled. Decided to try myself about 8 yrs ago with some Fluorinert FC-77 liquid that I acquired. Modded three quartz watches & they are all going fine to this day. Best to do on eco-drives or watches with very long battery life, due to doing battery changes inside a pot of liquid with the watch submerged. A small circle of very thin closed-cell foam should be added to the top of the movement prior to closing the caseback to allow for thermal expansion of the liquid. Leaving a tiny bubble in the face I also find quite appealing.

[@amjed8985]

This is so interesting Greg, I’ll ask my watch guy to try it for sure. Thanks!

[@964tractorboy]

Thanks Greg. That was all news to me. As I'm generally a "meat and potatoes" guy I don't see myself diving into this, but look forward to seeing the results of those more daring.

[@kleemanjad]

Great info. They say it also improve the display view during diving..

[@andrewmarriott4033]

Great insight greg thanks for the video

[@rickychoda6054]

Very well explained ❤

[@ant9072]

Thanks just the info I needed.

[@cunawarit]

When I've seen hydromoded watches tested the water resistance is not twice more, it is over 4000m and that's all the chamber would go to. Basically way beyond anything anyone will ever do. It makes battery changes a mess! And from now on you will have to do them yourself because no watchmaker will want to do it. But it's ideal for a little inexpensive watch like an F91W, because you don't have to bother changing the battery. Once it dies make a new one! The mechanical watch will not even move if you fill it with oil! The balance will literally not move! So it isn't just not recommended, just don't do it! And hydromods are not very intense, just do it :) it's super simple.

[@WyvernDotRed]

Recently I had my daily-driver watch, a GBD-100, die to water damage after I got the battery changed. Found a great deal on a second-hand GBX-100, which I plan to hydro-mod before turning it into my daily-driver again. Next to adding a colour filter to attempt to solve my pet peeve of the blue-ish tint the MIP display has. Will see how this goes and how that screen handles getting drenched in oil, ofc. I am testing it on a cheaper watch first. On the movement, a Quartz based movement will either work correctly or not at all, as the (stepper)motor tries to move in distinct steps, which it either manages to or fails at. If it does work, it would take more battery power to move the hands around from the resistance, making now messy battery replacements more frequent too. A mechanical watch would get destroyed by this mod, the column wheel will not work correctly in oil due to the drag. This information is sourced from various videos and forum posts on this subject, if I remember I'll reply with my results.

[@markhannum1049]

I notice that in the past two videos you are wearing what looks like a Casio MTG watch. I don’t see any of those being warn so it makes me feel good to see you with one.. I just really like mine as a first Casio watch. Keep up the good work.

[@GoodTimekeeper]

Yes, that’s my old MTG-900 which I bought in 2006.

[@zbilya2289]

Did it few days ago on Casio A158W. Sadly oil leaked out of crystal...

[@panosvrionis8548]

How?? Maybe the crystal is faulty or not an original casio. I did that before 6-7 years and it works perfectly.

[@brunosco]

Maybe the oil was not viscous enough?

[@richardwagnerjr]

I did this on a g-shock, to my knowledge you cant do it on a regular casio. Anyway I used mineral oil and it worked great. I also got tired of it and drained the oil out and the watch is fine. The auto light feature stops working though.

[@pauljosephbuggle3722]

Very interesting and I'm going to look into it. But I don't think it's up my alley.

[@2nd_a_dad4791]

From what I can tell, it makes more sense for an analog dial as opposed to a digital display. I think maybe it acts like an anti reflective coating?

[@BarnOwl61]

Do not, never, ever, try this with a mechanical watch. It will stop immediately, the balance and hair spring will never survive this action.

[@d.r437]

Hello. Tell me please, Is it possible to do on the clock with tough solar? Won't it hurt? I have an AQ S800 I would like to make myself. Thanks.

[@freequest]

Yeah, I am like, you don't modify watches apart from maybe a strap. Sadly I am one of those guys that like the watch as is. 🤣

[@Mike23443]

As a watchmaker, here's a few observations, comments and opinions. 1. This is a one way street. You cannot un-oil a watch. You'd need to fully replace the movement and full wash the face, which may end up causing damage or decolorization of some kind. 2. If a watch has a particularly poor water resistance, the oil may end up leaking out of it at some point. 3. Changing the battery in a watch treated this way is a pain in the ass. 4. This cannot be done to any mechanical watch. 5. A quartz watch submerged in oil will have a much shorter battery life as the movement of all components will have increased resistance due to the difference in weight and viscosity of the oil compared with air. 6. Depending on a movement, if the quartz crystal is not encased and will also become submerged in oil, its frequency response will be different, causing the quartz watch to not keep correct time, tho the difference may well be beyond negligible and certainly more tolerable than what mechanical watches have to suffer anyway. 7. Water resistance may become enhanced, however if you are looking to go diving beyond 500m depth, there are other issues that would likely arise making this a somewhat unreliable solution. Then again, this use case is so extremely rare that it's probably not worth mentioning. And you're certainly not going that deep if you do this to a watch that only has 30m depth to begin with. opinion:: It's a weird fad. Personally all I see when I glance at these is a riced out, fully stanced miata. Call me a pompous gatekeeper, but this is an aesthetics first mod which I would very rarely consider worth the effort, given the visual results. And I think it makes you look like a dweeb. But that's juet a philosophy thing. It's like engraving things on your watch. I think it's childish and that it ruins the watch. Then again there isn't much to "ruin" in a watch that costs less than a 100 dollars.

[@ameliazM]

I just wish manufacturers do dynamic pressure ratings on their watches in the future. Simply pressing buttons even on hydromods changes the story a lot.

[@JorgeGylmar69]

1 year whit my AE1200WHD-1A oiled and looks awesome and work well

[@stevehuffman7453]

FACT: Liquids cannot compress. Logically, if you remove ALL the air when you do the hydro-mod, the back and crystal can no longer deform or bend under pressure. (they can if there is an air bubble of any size.) At 100 meters or 54,000 meters depth, the external pressure and internal pressure of an oil filled watch (or oil filled camera housing and digital camera) are the same; they cancel each other out. Presuming the electronic components and battery or batteries used are not crushed by the pressure, the watch should continue working. An quartz analog watch may not be able to move the hands because of the pressure at the deepest spot in the ocean ... but a digital watch display would be unaffected - provided the board and LCD's or LED's are not crushed. Technically, a liquid filled electronic watch would not have a depth limit. BTW, Casio under-rates the claimed depth ratings. On another channel, a guy took a $30 casio with a "30 meter" rating, put it into a water pressure chamber, and built up pressure until the watch broke. Depth that$30 "30 meter" watch failed? 668 feet! Over 200 meters! A little better than "splash proof". I wonder what depth a Casio G-Shock or other watch they rate at 200 meters will take before it fails? Obviously, other manufacturers may not under rate the depth as much as Casio does. Modern watches only have to be able to go as deep as the manufacturers claim. Vintage/antique watches ... who knows? They "may" have been ... "optimistic" ... before the regs went into effect. Question: I have a Casio FT500-W Forester analog watch. I uses two batteries. One for the light, and one for the watch.(both recently changed after the initial 15 months use.The watch battery died after 10 years 3 months.) Casio rated it for 100 meters, so it has gaskets and a seal for the crown. Since it is an analog watch, NOT a digital watch, would it be suitable for a hydro mod, or would the oil affect the movement of the hands at sea level to the top of Everest? I "swim like a fish" or "swim like a rock" ... your choice ... same thing ... so I don't go swimming. When boating or canoeing, I wear a life vest. My mummy didn't raise no fool ... and if she did, it was one (or both) of my brothers. There is an old "Native America" saying: "A man destined to hang cannot drown." As I don't know which fate is mine ... why should I give drowning a chance?

[@MaartenAnna]

I saw someone test a Casio G shock hydro mod to 400bar, before stopping. That’s 4000m of water pressure. The original same model broke after 60 bar (600m).

[@AmaroqStarwind]

I was told that hydro-modding could improve a digital watch’s overall readability… like, the viewing angles specifically. Is this true? Also, is it possible to remove the bubble when hydro-modding a watch? Perhaps using a vacuum chamber?

[@jimcao1860]

Hi Greg, do you think a Citizen Promaster Aqualand with the depth gauge is a candidate for hydromod? Wondering if the depth measurement will impact the depth feature...

[@phil2082]

With a depth gauge? No. It will break that. Air compresses, liquid doesn't.

[@markloubser2433]

Properly done it will be infinitely depth resistant but; when subject to temperature change ie: warm up that oil will expand and have to get out. Air is compressible and can be contained to a point, not a liquid.

[@Hi-vy9lu]

Oil is also compressipble, not like water

[@utku486]

@@Hi-vy9lu no it isnt

[@washedtoohot]

@@utku486why would oil not be compressible? Honest question. Is it because it’s a liquid? According to my (faulty) understanding, it is compressible but it will heat up.

[@sorinconstantinescu3218]

greg please, can you tell me what type (model) of battery (capacitor) it has casio gw-b5600mg

[@GoodTimekeeper]

It uses the CTL1616.

[@freequest]

Wonder how it would change the look of one of these cheaper Casio Analogue watches. I would guess the dial would be crystal clear.

[@juancarlosdelmoral1919]

If I were to do so, it would be done on a watch that has a long-lasting battery, so I don't have to go through this process every 1 to 3 years.

[@nicorando3788]

Doesn't make any sense whatsoever the Hydro mod so I pass this one.

[@lancermaza6726]

I’ve seen some of those hydro moded watch videos.. seems like quite an interesting mod and the outcome is quite nice, but I don’t have any watch that can be used as an experiment yet.

[@WolfgangVonKempelen838]

@Douglas Pantera I am not planning on diving down to 500bar 😉

[@ELEVOPR]

Has anyone ever done this to a Solar 6 band watch? I can't imagine having to change the battery after hydro mod, you would have to start all over again? Mod is easy, you just have to be patient? Has anyone ever had their watch leak while wearing it?

[@GoodTimekeeper]

I haven't seen a KZbin video with a hydro mod of a Solar, Multiband 6 watch. I would guess that means someone probably HAS tried it but nobody has done it successfully, otherwise they would have shared a video about it. And, in some of the videos I've seen, folks admit that the watch might leak a little bit of oil right after the hydro mod is done. But it's minimal and it usually stabilizes. It might also be because there's a little oil stuck in the small gaps around the different parts of the watch case, including around a moving bezel and places like that.

[@ELEVOPR]

@@GoodTimekeeper Yes I kind of figured it myself, it was probably attempted but failed at one point, Still I would love to see a video on it and put to the test.

[@MrPleers]

I imagine an oil-filled watch will be very messy for the one who needs to service, repair it.

[@chrisr6710]

“Hello, I’d like the battery changed on my watch please” “Sure, anything about the watch you’d like to tell me before I take the back off?” “Nah, it’s all good” “Arrrrgghh, thanks for ruining my tools and work bench”.

[@CraisonBailum]

One does not repair a digital quartz. Buy a new module. Replace.

[@MrPleers]

@@CraisonBailum Nope. Digital watches can be repaired. And are repaired. In fact, with digital watches from the 70´s you will have to. As spare module are hard to get.

[@DzejWiJV]

Seriously, everyone who is wearing two watches looks like mental hospital patient...

[@MrPleers]

Like the person wearing them has a split personallity. And each of them needs his own watch.

[@freequest]

Before the ease of access to mobile phones, people wore multiple watches to keep track of the time in different time zones. So it's a holdover from that time Marc from island watch does the same thing, and in one of his early videos, he explains how he started wearing two watches. Also, wearing a watch on the bottom of the wrist is another old fashioned idiosyncratic hail back to when pilots needed to see the elapsed time without taking their hands off the stick. And don't worry about it to the modern generation. It's just weird but still interesting.

[@MrPleers]

@@freequest That is what watches with GMT hands are for. Or in case of a digital one, the worldtime function.

[@jamesrlewin]

That's why God made us with two wrists.

[@skyry101]

Except for Marc from Long Island Watch lol

[@ElderPinto254]

oil filled pulsar cheap diver went to 1.5 km deep

[@Yinn224]

Saw a pretty cool video by “Beyond the Press” channel where they crush watches in a deep sea pressure chamber. kzbin.info/www/bejne/fKixd6xodpylo7c They have crushed G Shocks, Citizens and Vostoks. Amazing, the hydro mod worked and a cheap Pulsar Quartz watch survived all the way to 300 bar (3000 meters), the max pressure for that chamber and probably could have gone deeper. So at least, the increased water and pressure resistance is legit. Have thought about messing with one myself.

[@valor1630]

somebody mod hack the AEL to a longer duration pls

[@jumbo_mumbo1441]

For those interested, others have also reported battery life is noticeably negatively impacted.

[@steffen2165]

Yeah, dies within a few weeks

[@brunosco]

For analog displays, not digital ones, I assume?

[@jumbo_mumbo1441]

@@brunosco from what I was reporting, yes. I don't know how this would affect a digital display watch as I haven't tested it, but I assume it shouldn't impact the battery as the components are static

[@Nykken777]

"Beyond the press" pressure tested an oil filled pulsar that was rated for 100m, and it survived 3000m (link below) kzbin.info/www/bejne/fKixd6xodpylo7c Don't think I am going to do is myself, but it sure is interesting.

[@tydshiin5783]

I don't think it improves the WR at all as that is only as good as the seals, but rather improve the pressure resistance instead Which is kinda only good if you're a diver or swimmer

[@MrLongboarder87]

The seals on a watch typically fail in water because you have a low pressure side (inside the air filled watch) and high pressure side (the water pressure outside of the watch. When the watch is under high pressure the watch case, case back, and crystal deform changing the tolerances of all the sealing surfaces allowing water intrusion. When the watch is oil filled the case, case back, and crystal can’t deform under pressure because oil isn’t compressible. The other issue with seals under high pressure is seal extrusion. When enough pressure is put on a seal it will push through the tiny gapes in the matting surfaces of the watch. When the watch is oil filled the oil acts as non compressible back up greatly increases the pressure a seal can handle before failing. If a watch is poorly machined, designed, or the seal isn’t the proper spec for the intended purpose then oil filling can’t magically fix it.

[@BarneyRolls]

A few too many woulds, coulds, shoulds 🙄 Any liquid (except of frothed milk shake et al. 😉) is incompressible to a very high degree close to 100%. So YES, the water resistance is upped a lot, definitely. Also a Quartz watch will absolutely run as precise as before (as long as the tiny oscillating quartz housing stays sealed), no matter LCD or hands. You MUST NOT NOT NOT NEVER NEVER NEVER do this with a (swiss lever escapement) mechanical watch - NEVER ! ! ! If you have a watch with a piezo speaker for an alarm expect the alarm to be.... louder?! I wonder... 🤷🏻‍♂

[@russellharris5072]

Battery change=messy,setting the time=messy.I would use a Chinese copy,they now also copy the world time watch AKA Casio Royale...........................................

[@goatreviews]

Fantastic video, Greg! 👌 As requested, here's my first ever Hydro Mod attempt! - kzbin.info/www/bejne/a5q0pJaJgdKpb5I I have mixed feelings about the process, and results 😁 I WILL be trying this again in the near future!

[@TerryHesticles]

Hydro modding is definitely not for me

[@chrisr6710]

I’ve only just stumbled across this hydro-mod thing. The one video I’ve watched so far killed the watch instantly. What a waste. I’m sure there are successful attempts at this but, nah, no thanks.