Waterproofing a Video Watch

Your statement doesn't make sense. You say you got a waterproof watch, but then proceed to tell us how you tried to make it "waterproof". Explain in more detail please.

It would also help if we knew the make and model of the watch.

As far as your calculation goes, 4mH₂O = 4 x 39.37inH₂O/mH₂O = 157.48inH₂O.

157.48 x 1.028(specific gravity of seawater) = 161.89inH₂O.

161.89inH₂O x 0.036psi/inH₂O = 5.838psi, not 20psi.

In light of this, I would try to think of another screen name, since hydrogen is even lighter than air.

How about double zip lock bags?

Try to allow less hydrogen to get in your head, then all will be OK.

The watch was described as being waterproof. It has no make and model and uses screw on rubber sealed caps for the usb port and microphone. I connected a tube to the microphone hole, put the watch underwater, and applied a small amount of air pressure to the tube and as I expected, loads of bubbles came out from various places. They said it was waterproof to 30 meters! Here is where I got 20 psi from: http://www.calctool.org/CALC/other/games/depth_press I used depth at meters and set it to 4 and I used pressure at psi and got 20.

Splitting the difference: anisette (e.g., Pernod). Or for the adventurous, absinthe.

http://www.calctool.org/CALC/other/games/depth_press I used depth at meters and set it to 4 and I used pressure at psi and got 20.

Actually, if you are going for 2 significant figures, it would be 21psi (20.5275 rounded).

The answers there are given in absolute pressure, as should be when figuring multiple conversions, so "Let the browser beware."

You haven't answered the question: "How much pressure was it?" (by Lyn). If it was over 5.8psi gauge pressure (=20.5 absolute pressure), chances are you ruined the watch.

Your first calc of 4mH₂O ≈ 5.7 psid was better.

Wow. I reread the OP and found that there was no mention of the water type; I just _{made an}ass_{out of}u_andme'd...

Do you understand though, the OP's misunderstanding between gauge and absolute pressure?

Yeah, psig vs psig vs psid. But I don't get 20 or 21 out of any of these.

So what do you get? And please, show your work.

Apologies for typo; I meant psia vs psig vs psid, of which the last is most relevant.

At 4m submergence, the seawater pressure ≈ 5.85 psig ≈ 20.54 psia. Unless the watch leaks, its internal pressure is atmospheric ≈ 14.69 psia. This gives ~5.85 psid, which is what the stem seal needs to withstand.

Maybe replace a tiny O-ring and/or case gasket?

I can't say what the solution is, but our numbers match.

You got ripped off. I've never seen a watch advertised as waterproof, only water resistant...................go with the zip lock bags.

Look here

I've owned several dive watches over my 63 years.

I'm especially fond of a French made dive watch I bought in the early 60's that has worked flawlessly since then. Except, oddly enough, that it refused to work while I was in Vietnam. Go figure.

Hooker

Still sh1ty?

_{(My Seiko never had a problem even to ~200ft, but of course it mechanical and analogue)}

LOL. Yeah, I guess. Dien Bien Phu... Dang watch stopped both times I entered the country and worked again both times I left.

Hooker

Has anyone though about atm pressure that would be inside of the watch helping to resist the force of the water trying to enter.

Assume 1atm(14.6959psia) in the watch resisting the force of the water 5.58psig plus the 1atm on top of the water gives 20.5275pisa.

Which comes back to the 5.58psig of water trying to get in.

Just my though's...oh I did go to the op's site, it gave seawater and I also used 4m.

I believe it is the extrusion of the o-ring that is preventing the water from entering the video

Er...beg pardon...

What is a video watch? One on which you can watch videos, when you are not wanting to know the time ?

What does one do with a water-proof video watch ? Watch videos while 20m under water...

Rather a confusing scenario, i am sure i have misunderstood 'Video watch'.

Video watches are becoming more popular. Yes, actually, you CAN get one which plays movies....grin!

There are several varieties out there. Check THESE out. (gotta LOVE ThinkGeek!)

It was a small amount of pressure that I applied with my mouth, so it will probably be around 2 psi. It is called a video watch because it has a camera in it. Because of this, it is quite thick and big.

It's also knackered - now. Recycle it and find a new one.

It is not, I removed all the black paint from the watch and I coated it in clear varnish. It resists pressure very well now.

Take off the watch, and put it in a water proof acrylic container, and put in on a lanyard around your neck, and then jump in and enjoy! Why buy a "waterproof" watch for a diver's watch if it not a diver's watch. Quit being a cheap skate.