Try taking a plastic down to 100' under water then filling it with air
from your regulator and closing the cap. It certainly does 'puff up'
when you return it to the surface. BTW - So does a diver if they forget
to exhale on the way up 8-(

If I have an empty bottle in the back seat over a winter's night I can
hear it cracking as the car heats up and the air inside expands.

Pirate_Dave
--
In article , Gregg Germain wrote:
Tailgunner wrote:


: Gregg Germain wrote:

: Tailgunner wrote:
:
: : I found a place that sells a gross at $20 ($0.07 each). Not much better. I
: : thought about bottles (free). But the deck would have to be removed to install
: : them. Next year I am thinking of replacing the deck so maybe. They are
: : certainly not flammable even with the caps epoxied on.
:
: One has to wonder what happens to the bottles if you put them in
: during a chilly spring day, and then the seasons change and it's a 95
: degree Summer day.
:
: Or vice versa....if you put them in on a hot day, what happens in
: September or October. Do the bottles crush some? Does that imact
: flotation?

: Gregg, you're just paying too much attention. 8-)

Well you might be right about that ;^)


: I honestly don't think it would be that much of a change. Maybe if they were in
: direct sunlight they "might" expand. Tell you what, I'll ask one of our scientists
: here at work (WHOI) and see what they think and report back.

I only ask because I've seen closed, empty plastic bottles puff up in the
sunlight.



:
:
: --- Gregg
: "Improvise, adapt, overcome."
:
: Smithsonian Center for Astrophysics
: Phone: (617) 496-1558
:

: --
: Tailgunner