So the "Pepsi generation" might end up being the "Alzheimer's
generation"?
http://www.laleva.cc/environment/alu...lzheimer2.html
More good news... NOT! ;-}
David


http://pstuning.com/ "Jeff Wisnia" wrote in
message ...
Metal content: Aluminum Pepsi cans.

I long ago learned that soda in plastic bottles loses its fizz after a few
months because the CO2 slowly leaks right through the plastic, but I
thought that soda in cans would keep "forever".

Last weekend I discovered a 12 pack carton of Pepsi I'd hidden behind some
other stuff in a kitchen cabinet so the kids wouldn't find it and consume
it all in minutes. When I went to remove it the carton was stuck to the
cabinet floor and when I opened it about half the cans felt far lighter
than they should and there was evidence of dried sugar on them and the
carton.

I looked at the date code on the cans and gave myself a "dope slap" when I
realized that the carton was about three years old.

I was curious about what Pepsi had to say about that and called their
consumer line.

The lady I spoke to was quite prepared for the question, so I expect they
hear about "old" cans leaking frequently.

The first thisg she told me was that drinking the Pepsi from a can which
had leaked wouldn't kill me because the high acidity in the product
prevented the growth of bacteria. So, I guess Pepsi is one of those
"foods" like Honey and mayonaise which can stand being "opened" and then
stored at room temperature without spoiling.

She said the high acidity was also the source of the leakage I'd found.
The cans are lined with a coating which is intended to keep the product
from touching the aluminum, but it isn't always perfect, and if there's
the tinyist imperfection in the coating the Pepsi will corrode its way
through the can, sometimes in as little as 6 months.

She also told me, "It only takes one." And that if one can in a carton
develops a pinhole leak, a chain reaction takes place because the outside
of the cans doesn't have that protective coating and if it gets wet with
Pepsi it will corrode through faster than it will from the inside.

The bottom line is that Pepsi expects their cans not to leak by the "Best
Taste if consumed by" date on them, but leakage after that date is not
unheard of. (I didn't have the chutzpah to ask her for a "warranty
replacement", nor did she volunteer one.)

I was curious to see where the leaks occurred and what they looked like so
I took the least full unopened Pepsi can and punched a hole in the center
of the bottom with a nail set. I shook out nearly all the remaining liquid
and then pressurized the can with 10 psi air by squeezing a soft rubber
washer between my air hose nozzle and the can.

I stuck the pressurized can under some water in a bucket and spotted a
string of bubbles coming from a spot on the side of the can.

Looking at the can with a 10 power loupe I "thought" I could see a tiny
white spot where the bubbles were coming from.

Sacrificing my 5 cent recycling deposit in the name of science I cut the
can open.

Here's what I found:

http://home.comcast.net/~jwisnia18/jeff/pepsi.html

The whole inside surface of the can was peppered with little freckles
where corrosion had started to gnaw through the aluminum. And, I could
easily see light through the pinhole which leaked.

It was sort of reminiscent of the leak which developed in a 3 inch long
steel pipe nipple about 6 months after I used a couple of them to stand
dielectric unions on the top of a replacement electric water heater I
installed in our home. When I did that I didn't stop to think about the
fact that the electrical feed's grounding of the heater and the code
required grounding of our copper plumbing system would close the circuit
and nullify the supposed benefit of using those fancy unions. Both nipples
got severely clogged with rust and I discovered the problem when a pinhole
leak punched through at the root of an exposed thread, which was the
"thinest" part of the nipple.

http://home.comcast.net/~jwisnia18/jeff/nipple.html

I found out later via a tech note at rhe Rheem water heater company that
they now advise against using dielectric unions when installing their
tanks for the very reason I learned by experience.

Case closed...I think...
--
Jeffry Wisnia

(W1BSV + Brass Rat '57 EE)

"Truth exists; only falsehood has to be invented."