Brian Whatcott wrote:
I have a thought. It's off the top, but it's worth testing.
Any acidic solution tends to eat metal.

Not necessarily. Vinegar is acid, but doesn't harm metal...chlorine
isn't acid, but is corrosive and does destroy metal.

Water doesn't even
need to be acidic to promote pin hole corrosion in some
aluminum alloys. Oxygen depleted water is hell on stainless.

But alkaline solutions, in general, don't eat metal so well, or at
all.

Urine can be alkaline or acidic...doesn't seem to matter in a metal
holding tank.

I have this hunch that waste water rendered slightly high pH
of neutral would help a tank to survive.

Waste and water have about the same pH...7-9...so I don't THINK pH is
the key...'cuz the same aluminum alloy tank used to hold water will last
20-25 years.

I'm not a chemist, so I can't tell you why that's true, only that it has
proven to be.

--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://shop.sailboatowners.com/boat_odors/

On Sat, 27 Oct 2007 10:02:59 -0500, Peggie Hall
wrote:

Urine can be alkaline or acidic...doesn't seem to matter in a metal
holding tank.

Well who'da guessed! Dilute uric acid alkaline! I picked out the
Corning pH meter, all set to put it to the test.
But the 3 volt lithiums need changing. Oh well.

I have this hunch that waste water rendered slightly high pH
of neutral would help a tank to survive.

Waste and water have about the same pH...7-9..

??

Thanks for responding

Brian W

Bummer...I miss direct overboard discharge. :-(.

Glenn.

"Peggie Hall" wrote in message
...
Glenn (s/v Seawing) wrote:
Did I read that correctly...urine will destroy an aluminum holding tank?

Yep. It'll destroy ANY metal holding tank, even 316 stainless.

Bummer...my Father just had one made for his trawler. Any way to prevent
this?

Nope. But it's not gonna suddenly disintegrate. The average lifespan of
any metal waste tank is about 10 years. Typically, it'll start to leak at
a weld in seam or fitting within about 2 years...and turn into a colander
in about 10 years.

So you might want to tell him not to panic...it'll be ok for the next few
years. Just keep an eye--and his nose--on it. And tell him not to bother
repairing the first leak...'cuz the first one is always ONLY the FIRST
one. The time to replace it with a good quality thick walled plastic tank
is after it springs te first leak. Till then, he can relax.

--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://shop.sailboatowners.com/boat_odors/

On Sat, 27 Oct 2007 23:17:06 GMT, Brian Whatcott
wrote:

On Sat, 27 Oct 2007 10:02:59 -0500, Peggie Hall wrote:
Urine can be alkaline or acidic...doesn't seem to matter in a metal
holding tank.
.....
I have this hunch that waste water rendered slightly high pH
of neutral would help a tank to survive

..-
Waste and water have about the same pH...7-9..

I finally bought the silver oxide cells for my Corning pH meter, and
peed a sample to check - it read 5.5 pH - about where I expect.

But...but..but: I seem to recall that waste mater can soon smell
ammoniacal, and maybe THAT'S the alkaline component?

Brian W

"Brian Whatcott" wrote in message
...
Waste and water have about the same pH...7-9..

I finally bought the silver oxide cells for my Corning pH meter, and
peed a sample to check - it read 5.5 pH - about where I expect.

But...but..but: I seem to recall that waste mater can soon smell
ammoniacal, and maybe THAT'S the alkaline component?


Peggie doesn't have that problem. Peggie's **** don't stink. (or at least
she thinks that!)

Did you hear the real reason why they didn't want to let more water out of
Lake Lanier until recently? They said it was because of some endangered
mussel but that was just smoke and mirrors. The real reason was because
everything below a depth of about ten feet is toxic as hell. Too many people
emptying their holding tanks full of chemicals that don't work.

Greg

On Sat, 17 Nov 2007 15:17:28 -0500, "Gregory Hall"
wrote:


"Brian Whatcott" wrote in message
.. .
Waste and water have about the same pH...7-9..

I finally bought the silver oxide cells for my Corning pH meter, and
peed a sample to check - it read 5.5 pH - about where I expect.

But...but..but: I seem to recall that waste matter can soon smell
ammoniacal, and maybe THAT'S the alkaline component?
....
Did you hear the real reason why they didn't want to let more water out of
Lake Lanier until recently?.... because
everything below a depth of about ten feet is toxic as hell. Too many people
emptying their holding tanks full of chemicals that don't work.

Greg




eeeiooow!

Brian W

I see that Neal, aka Wilbur, has assumed yet another identity.

Gregory Hall wrote:

Peggie doesn't have that problem. Peggie's **** don't stink. (or at least
she thinks that!)

Did you hear the real reason why they didn't want to let more water out of
Lake Lanier until recently? They said it was because of some endangered
mussel but that was just smoke and mirrors. The real reason was because
everything below a depth of about ten feet is toxic as hell. Too many people
emptying their holding tanks full of chemicals that don't work.

Greg





--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://shop.sailboatowners.com/boat_odors/

On Sat, 17 Nov 2007 15:17:28 -0500, "Gregory Hall"
wrote:


"Brian Whatcott" wrote in message
.. .
Waste and water have about the same pH...7-9..

I finally bought the silver oxide cells for my Corning pH meter, and
peed a sample to check - it read 5.5 pH - about where I expect.

But...but..but: I seem to recall that waste mater can soon smell
ammoniacal, and maybe THAT'S the alkaline component?


Peggie doesn't have that problem. Peggie's **** don't stink. (or at least
she thinks that!)

Did you hear the real reason why they didn't want to let more water out of
Lake Lanier until recently? They said it was because of some endangered
mussel but that was just smoke and mirrors. The real reason was because
everything below a depth of about ten feet is toxic as hell. Too many people
emptying their holding tanks full of chemicals that don't work.

Greg


Wilbur, is that you?

Bruce-in-Bangkok
(Note:remove underscores
from address for reply)