Depending on the test tube light design, there are a few ways to prevent
lens loss.
First, don't lubricate the o-rings, simply wet them (very lightly) when
installing the lens. Lubrication makes them way too easy to pop off when
hot, the pressure pushes them right of the end. The slight moisture will dry
quickly and never be seen again.
Relieving the pressure while pressing the lens in place can be done in a
couple of ways. If it has an easily loosened compression type sealing gland
on the cord, just back off the nut (not the gland itself, use two wrenches)
and wiggle the cord. This will allow air to escape out around the cord while
the lens is being pushed on. Once the lens is in place, re-tighten the nut
on the gland. If the gland is not accessible, (or easily loosened), you can
"vacuum seal" the lens in place. Place the head on a flat surface and push
the lens on till it loosely touches the first o-ring. Now turn the light on
for a few minutes. This will heat the lens and the head at the same time.
Once it is nice and warm, turn the light off and grasp the lens with a towel
(or something of that nature) and push the lens in place. Once the whole
assembly cools, it will be in a vacuum state. Naturally, the head material
needs to be such that it can be burned for a short time out of the water for
this "vacuum" method.
Aluminum and Delrin will have no problems with this. PVC or others would be
highly suspect.
Any high quality glass lens will have no problems either. The o-rings can
stand alot of heat as well.

You should always pull a test tube style out of it's reflector before using,
just to check the seals. The lens can be hit in such a way that it cracks
the lens at the base, (where the o-rings are), but still appears to be just
fine while still in the reflector because this area is hidden from view.
Dell Motes
Dive Rite
117 W.Washington St.
Lake City, Florida 32055
www.dive-rite.com


-----Original Message-----
From: Paul Harris <paul.r.harris@te*.ne*>
To: 'Chris Elmore' <ElmoreC@gw*.sc*.ed*>; cmilz@Mi*.ED* <cmilz@Mi*.ED*>
Cc: techdiver@aq*.co* <techdiver@aq*.co*>; cavers@cavers.com
<cavers@cavers.com>
Date: Wednesday, May 10, 2000 12:07 PM
Subject: RE: AUL canister light / light cord


>Chris,
>I'm not sure about this as a solution.
>Some friends and I were discussing non-wicking wire.
>My (humble) opinion is that you need some way of transfering
>air from the light head when you push the test tube on otherwise
>the positive pressure will push it off.
>
>I have noticed that it is much easier to remove or replace the
>test tube when the lid is off the cannister.
>
>r
>Paul
>
>> Claudia,
>>      When I replaced my electrical cord I peeled the
>> insulation back from both ends (after cutting it to the right
>> length), put a wad of aquaseal around the wires, then pulled
>> the insulation back up. This will keep any water from getting
>> through a nick in the insulation and into the canister which
>> may be what's happening to yours.
>> C.
>
>--
>Send mail for the `techdiver' mailing list to `techdiver@aq*.co*'.
>Send subscribe/unsubscribe requests to `techdiver-request@aq*.co*'.
>

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