Convert a water-resistant sport watch into a dive watch

Problem:  I spend long hours underwater at shallow depths and I need to keep track of the time.

Parameters: I don't need the fancy features of a $500+ saturation dive watch, however the cheap "water resistant to 50M" watches are not up to the task.  I don't even need the features of the cheap watches either, I just need something that will display the time and not get destroyed by a few hundred hours at 20 feet.

Solution: Encapsulate a cheap sport watch in clear polyester resin.

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Step 1: Get supplies

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Step 1. Get supplies. Cheap water-resistant sport watch with large display, suitable mold, clear resin, hardener.

Step 2: Prep watches

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Step 2. Prep watches, set time/mode, remove bands.

Step 3: Add first layer

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Step 3. Add first layer, 1/2oz each.  Mix resin and hardener according to instructions on package.  Pour a thin "face layer" and wait 30 minutes for it to gel.  Otherwise, the watch will sink to bottom and will not be encapsulated properly.  Use stir stick to remove any bubbles from bottom of mold.

Step 4: Add Watches and second layer

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Step 4. Add Watches and second layer, 1oz each.  Use stir stick and coat watch face with resin, remove all air bubbles. Pour a some resin on top of first layer, place watch in resin, move it around to dislodge any air bubbles.  Pour in rest of resin layer.  Watch should be completely covered.  Let sit 30 minutes until this layer gels.

Step 5: Add straps and third layer

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Step 5. Add straps and third layer, 1/2oz each.  There needs to be a way to strap the watch to your person, you should have figured out something to use and have it ready.  I used the straps off a sleeping bag, they come with locking clips and plenty of strap.  Use stir stick to coat both sides of the strap, removing as much air as you can.  Place strap on top of second layer.  Pour the rest of the third layer over strap.  Wait 4 or so hours.

Step 6: Remove from mold.

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Step 6. Remove from mold.  After the resin has mostly cured, 4 hours or more, it will shrink slightly and pull away from the mold.  It should pop right out, perhaps with a gentle tug. 

Step 7: Inspect Awesomeness

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Step 7. Inspect Awesomeness. Two totally encapsulated watches for a total of about $50 (Two watches: $17 each, 1/4 of the $30 resin+hardener, found straps), they should meet all my dive watch needs.  If the any of the watch is exposed, simply mix some more resin, place in the mold, and put the watch in on top.  This should form a new layer and bond to the previous layers.
VadimS5 years ago
It look great, you would probably only use it for diving so daylight savings time would probably not be a problem (unless you like cold water or are going to the Caribbean or something). The watch I have now is on it's third battery but I've had it for 15+ years.

Another method (as previously stated) is to fill it with oil, just re- assemble it in a cup of oil to make shire there are no bubbles. Mineral oil is your best bet.

The most likely spot for them to leak is the buttons.
Nice idea, well except from resin that becomes rock solid could transparent heat glue but in a smaller mold do the job (and also keep the buttons functional)?
not hot glue (too week) but you can buy clear two part silicone that would work (not RTV).
rdillon3 years ago
Ummm - Nosey question from an interested diver... What do you do while you're spending many hours underwater? :-)
safonatt (author)  rdillon3 years ago
I dredge for gold off the bottom of the Bering Sea (diver operated, suction dredge), I'm actually about to get in the water in an hour. See Discovery channel for a series about it Spring 2012.
that's so cool it must be amazing
I am enlightened :-) Thank you!
I don't see the point - this watch is £32 (approx $50 US).


lemonie5 years ago
If these are water-resistant, filling them with oil is an idea for an alternative. But you'd have to totally-fill them.
I like the enclosure you've done here, it looks very good.

safonatt (author)  lemonie5 years ago
Thanks. Yes, I've looked at oil-filling, and plan to do that if I ever need to make an enclosure that requires penetrations, such as increasing water-resistance of electric or hydraulic motors.
Jobar0075 years ago
You could have water inclusion problems if you are using polyester resin instead of epoxy resin. If there are any bubbles at all in the resin (when using polyester) they will eventually fill with water and be subject to those problems... It is still cheaper than a scuba/free dive watch. Awesome idea!
safonatt (author)  Jobar0075 years ago
Ah, thanks for the tip.  Next time, I'll look into epoxy resin.
SWV17875 years ago
I think it looks cool but I think it might get expensive when you need to purchases a new watch, resin, and webbing every time your battery dies
safonatt (author)  SWV17875 years ago
Thanks for the kind words.  I did think of the battery issue, but the batteries on these watches last for years, especially without using the light.  A solar powered watch would be cool, but likely not worth it.
How about if you stretched a couple layers of rubber recycled from bicycle inner tubes over the buttons and then set drinking straws into your casting to allow access to the buttons to reset time as needed (Daylight-savings time for instance). You could also attach a small solar panel recycled from a calculator and a diode to prevent electrical flow-back. but you might have to find a rechargable battery if the watch's one isn't already.
mikeasaurus5 years ago
I like the look, it's like a time-puck or something.

Can you elaborate on what fails on the water-resistant watches to make them not suitable? Where do they leak, the back cover, the buttons or the faceplate?
safonatt (author)  mikeasaurus5 years ago
I wouldn't know what fails, I've never tried to take a cheap non-diving watch underwater.  I was doing research on which watch to buy, and didn't find anything but expensive ones that met my requirements.  Maybe they were only $250 and up, not all were $500.

The instructions on this "30 Meter" watch that I used here say "Do not press any buttons underwater" and "Watch is not a diver watch and should not be used for diving" and "Rinse watch with fresh water after exposure to salt water".

Reading the wiki page http://en.wikipedia.org/wiki/Water_Resistant_mark and other pages, it was stated that watches are only "water resistant" to varying degrees. 

I dive in unique conditions, cold, salty, harsh environments, getting knocked around, and I need a watch that will do the job and not be a big loss _WHEN_ it gets destroyed.
tukas5 years ago
Yes, but still cheaper than $500.  Maybe a solar watch thing like the solar calculators.