G-Shock Hydro Conversion & Pressure Test

    Posted the 13th day of October in 2008 by Riley.

Adan has been experimenting with hydro converting G-Shocks. This modification allows G-Shocks to go well beyond their 200 meter waterproof rating. It can be a little tricky, but it looks like he's got the process down tight now. His Mudman has survived more pressure than any other G-Shock.

To convert the watch he fills it up with 5000 density silicone oil (used in RC cars).

Silicone Oil

First the G-Shock needs to be disassembled.

Then the silicone oil is warmed up to about 50 C (122 F) and the module is slowly filled.

And then the G-Shock is reassembled while submerged in the oil. It can be tough to completely fill the module and not have a few small air bubbles.

Converted DW-9300 Raysman
Converted G-9000 Mudman
Converted GW-9100 Gulfman
Converted GW-9000 Mudman

Once the G-Shock is back together it's time to test it in the pressure chamber.

Pressure chamber
A new world record?

Here's a video of the pressure test.

Adan has successfully tested his GW-9000 Mudman to the equivalent depth of 1,000 meters. As far as we can tell this is a new world record.

You can do this yourself, but please be careful.

Adan's Site

Also, Adan just posted a GW-M5600 Hydro Conversion.

Filed under: Custom G-Shock, DIY Project



    Great test indeed!

    Just a comment!

    It must be atleast one small bubble left inside the case because if all the bubbles gets removed then the oil could potentially cause the case or seal to explode when exposed to heat from the sun and when temperature goes donw in deep waters the oil could compress allowing the water to get into the case.

    So it is best leaving atleast one small bubble and not try to get rid of it!


    Just a FYI, in general oil (hydraulic fluid) is not compressible. Hence the reason why it is commonly used for industrial hydraulic systems. Also the nice thing about oil (in general) it will not expand when subjected to heat, it has a coefficient of thermal expansion that is so high, that the watch would melt before the oil would expand. The only thing that changes when oils are subjected to heat it the viscosity of the oil. So JoakimAgren please understand material properties before publishing false information. Oil is used in engines because it has an extremely high heat tolerance and wont compress under high extremely pressures.


    I was just reffering info that I read from someone who made one of the first Hydro mods. So I was in the belief that the bubble was neccessary due to heat and pressure changes the watch might be subjected to.

    If this is incorrect info it is good that you let me know!

    But are you sure that silicone oil behave the same as regular engine oil?


    I'm not familiar with the properties of silicone oil. Whatever Adan did works, so maybe he can offer some more insight on the subject.


    Hey Riley & JoakimAgren, I looked up the material properties for silicon oil. It behaves very similar to a normal "motor/hydraulic" oil. I'm advising that all air be taken out of the case, air is in fact compressible you could yield very negative results should enough pressure be place upon this watch if it contained too much air. My estimation would be if enough pressure was place on this watch with enough air in it, the watch's gaskets would fail then the battery and LCD assemblies would fail. Thanks for the post, I think that if this procedure was executed correctly that he could get a world record. Oh, the watch company Bell & Ross fills one of their watches with a similar fluid, and they have successfully achieved a pressure rating of 1200 bar. here is the link: http://www.bellross.com/download/notices/Hydromax-en.pdf


    Thanks for the information Adam2010.

    It makes sense the way you explain it.

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