[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [PSUBS-MAILIST] instant dive light

Hi all,
I have used a regular plastic flashlight for an extra dive light and filled it with oil.  At 60 ft deep the on/off button would push in but not pop back out, so you couldn't cycle it on and off any more.  O rings seemed to be strong enough to prevent ingress of sea water or leaking of oil on expansion...  BUT it was a plastic case which had some give.  The on/off problem was not solved by me.  A toggle might have worked.  A real dive light is not that expensive for the security it offers as a device that could become a safety critical item!
Gene Seus
 
In a message dated 10/16/2011 10:11:31 P.M. Pacific Daylight Time, ojaivalleybeefarm@dslextreme.com writes:
Hi Alan,
                   I think the switch gets filled with oil as well. I have it filled right now and it seems fine.  I did do a test down to 30' and is seemed ok.  The time I got water in it a couple of weeks ago was when I capsized my kayak and dumped all my scuba gear in the surf. I think since it got beat up a bit may have leaked some mineral oil.  Also with my first attempt I didn't fill the void in the end cap. 
 
What I'm worried about is the changing temperature.  If it heats up in the sun before diving the mineral oil is going to expand and push out past the o rings, then when it gets cold the oil is going to contract and draw in seawater.  But it may not be enough of a pressure difference to actually push past the o rings.
 
Brian 

On Sun, Oct 16, 2011 at 9:24 PM, Alan James <alanjames@xtra.co.nz> wrote:
Hi Brian,
my concern with the flashlight is that if it has a push button type on off switch,
& you filled every void with oil, you wouldn't be able to push the switch in. If you left any air cavity
then water pressure at depth could push in your switch. In this case you need to add some sort of flexible
diaphragm or tube to it to enable the internal & external pressures to equalize.
Regards Alan
 
----- Original Message -----
Sent: Monday, October 17, 2011 2:50 PM
Subject: Re: [PSUBS-MAILIST] instant dive light

Sean,
               I drilled into the bottom of my duracell D battery and that area appears to be solid on these batteries.  I just got a new 3 cell Mag light with the new led emitter.  I don't think I'm going to worry about filling with expoxy because I think that top area that is void ( in the battery) would be strong enough to go at least to 100'.   Also I was able to fill the top area ( where the light is ) with oil and then slide the lens on and keeping all the bubbles out.  Then in the battery area the only problem is, there is a small void in the screw cap area that is hard to get oil into because you have to turn it upside down to screw it on.  I'm filling that area with wax (beeswax) to take up the void.  Going diving on Wednesday - hope it works !
 
Brian 

On Sun, Sep 25, 2011 at 5:49 PM, Sean T. Stevenson <cast55@telus.net> wrote:
Brian - alkaline dry cells have void spaces in them which will not be compensated by surrounding fluid unless they are specifically modified.  Have a look at the following link for details.

http://rogercortesi.com/portf/highpresbat/highpresbat.htm

-Sean



On 22/09/2011 8:15 PM, ojaivalleybeefarm @dslextreme.com wrote:
Had a bit of a malfuction with my mag lite dive light.  After a day of the light getting beat around in the surf I brought it home and laid it on my work bench.  When I went to pick it up I noticed a bit of oil underneth it and it was very hot.  I turned it on and it was still working, so I opened up the battery compartment and poured out the remaining mineral oil.  I think my o rings are not sealing good.  Three of the batteries were very hot, the other three seemed normal temperature, one battery had some discolouration.   Obviously there was a reaction taking place and a couple of the batteries were shorting, I imagine from salt water.
 
Brian

On Wed, Sep 21, 2011 at 8:35 PM, Alan James <alanjames@xtra.co.nz> wrote:
Hi Alec,
It was called a joiner Reducing 19mm x 13mm.
It's plastic, & I chopped bits off both ends & sanded slightly to fit.
Part of a garden watering system found in the local hardware store.
Only a few cents. Frank would have been proud of me.
The flashlight has 3 modes, full, medium & strobe. You cycle through by turning
the power on & off, however it seems to reset after a short period of being off &
then always turns on in full mode.
Alan
 
 
 
----- Original Message -----
Sent: Thursday, September 22, 2011 10:31 AM
Subject: RE: [PSUBS-MAILIST] instant dive light

Wow, that is remarkable. May I ask what the piece is that you screwed into the flashlight head? The one between the flashlight and the stainless nipple.
 
Thanks,

Alec


The contents of this e-mail are intended for the named addressee only. It contains information that may be confidential. Unless you are the named addressee or an authorized designee, you may not copy or use it, or disclose it to anyone else. If you received it in error please notify us immediately and then destroy it.

From: owner-personal_submersibles@psubs.org [mailto:owner-personal_submersibles@psubs.org] On Behalf Of Alan James
Sent: Tuesday, September 20, 2011 5:30 PM
To: personal_submersibles@psubs.org
Subject: Re: [PSUBS-MAILIST] instant dive light

Well done Brian,
I've got a book on making dive lights. http://airspeedpress.com/newlitebook.html it probably has
reference to how much pressure your bulbs could take, but it's packed away somewhere.
Modifying one of these existing lights seems easier & cheaper.
The flash light I gave the link to, I was intending for submarine use. If simply modified for
diving, the switch  being a"push in" type would possibly turn itself on under pressure or not be
able to be plunged if you got all the air out.
Regards Alan
 
----- Original Message -----
Sent: Wednesday, September 21, 2011 8:41 AM
Subject: Re: [PSUBS-MAILIST] instant dive light

Hi Alan,
                  Just got back from the harbor, succsess !!  I dropped it down to around 35' with the light on everything seemed fine.  It was difficult filling it totally with no air bubbles, I had one tiny one.  I may try to put some silicone on the O rings to keep any min oil from leeking by.  The next time I fill it I'm going to do it in a min oil bath so I can submerge the entire light in the oil to get all the air out.  Those xenon bulbs are apparently pressurized, not sure if that makes a difference.  don't know how much pressure, probably not much.
 
I would like to make an led light as well.
 
Brian

On Tue, Sep 20, 2011 at 11:37 AM, Alan James <alanjames@xtra.co.nz> wrote:
Hi Brian,
I got part way through making some LED dive lights by modifying some $20- lights I bought off "Deal Extreme".
900 lumen & free freight. They operate off around 4 volts, so I'm going to link them in 3s to operate off 12 volts. They have O rings at every join
& are made of a fairly thick aluminum. I cut the body down & pushed a hose fitting in the end, then soldered in wiring & put on a tube, ready to oil
compensate. The LEDs in general take tremendous pressure, I believe a similar oil compensated system went down 10 kilometers.
Regards Alan
----- Original Message -----
Sent: Wednesday, September 21, 2011 3:30 AM
Subject: [PSUBS-MAILIST] instant dive light

HI All,
                 I was pricing dive lights for the upcoming lobster season and was floored by the outragous prices they charge for those things.  So I decided to take my 6 cell mag light, which has a xenon bulb in it, and fill the entire thing full of mineral oil.  The mag lights have O rings at all the critical points of seperation of the different segments of the light.  I'm going to be dropping it down to 40' today to see if the bulb can take the pressure.  If not then I'll most likely go to an LED mag light. 
 
Brian