Hi,

I've always seen plastic watertanks, but the boat I'm buying has an old
aluminum one (I think it's alum: it's metal, and not SS). Is there any
advantage to alum over plastic or vice-versa? I'm planning on replacing it
with a bigger one, and first I thought plastic, but should I consider
aluminum instead? I've always disliked the "plastic" taste in the water
from a plastic tank.

druid
http://www.bcboatnet.org

On Tue, 02 Oct 2007 12:40:40 -0700, druid wrote:

I've always seen plastic watertanks, but the boat I'm buying has an old
aluminum one (I think it's alum: it's metal, and not SS). Is there any
advantage to alum over plastic or vice-versa? I'm planning on replacing it
with a bigger one, and first I thought plastic, but should I consider
aluminum instead? I've always disliked the "plastic" taste in the water
from a plastic tank.

My old boat had an aluminum water tank and it was fine. The one
before that was stainless steel. My present boat has black iron
(steel) tanks. No problems with any of them. On the other hand if
the plastic tank is properly designed and mounted, and sheilded from
UV damage, it should last a long time.

On Tue, 02 Oct 2007 12:40:40 -0700, druid wrote:

Hi,

I've always seen plastic watertanks, but the boat I'm buying has an old
aluminum one (I think it's alum: it's metal, and not SS). Is there any
advantage to alum over plastic or vice-versa? I'm planning on replacing it
with a bigger one, and first I thought plastic, but should I consider
aluminum instead? I've always disliked the "plastic" taste in the water
from a plastic tank.

A charcoal filter will take out the taste.

Casady

On 2007-10-02 15:40:40 -0400, druid said:

I've always seen plastic watertanks, but the boat I'm buying has an old
aluminum one (I think it's alum: it's metal, and not SS). Is there any
advantage to alum over plastic or vice-versa? I'm planning on
replacing it with a bigger one, and first I thought plastic, but should
I consider aluminum instead? I've always disliked the "plastic" taste
in the water from a plastic tank.

I prefer aluminum over plastic and wouldn't replace a perfectly good
tank with a bigger one, but would add tanks in otherwise unused corners
of the boat.

Our tank is plastic. We have a filter in-line for mostly sediment but
the charcoal element removed the last of the plastic and other
objectionable components (unless I leave the tank full for a Chesapeake
summer week or three, which will overload any filter.)

--
Jere Lull
Tanzer 28 #4 out of Tolchester, MD
Xan's new pages: http://web.mac.com/jerelull/iWeb/Xan/
Our BVI pages: http://homepage.mac.com/jerelull/BVI/

On Oct 2, 4:41 pm, Jere Lull wrote:
... wouldn't replace a perfectly good
tank with a bigger one, but would add tanks in otherwise unused corners
of the boat. ...

This seems like good advise. I keep hearing horror stories of folks
draining all their drinking water into the bilge when they spring a
pressure water leak. I always turn my pressure water off at the panel
when it isn't in use, but also have two tanks that are isolated so it
takes a greater level of idiocy to dump all the fresh water. I also
like to make my water into a working tank and keep a known good tank
in reserve in case something goes wrong there.

-- Tom.

"druid" wrote in message
news
Hi,

I've always seen plastic watertanks, but the boat I'm
buying has an old
aluminum one (I think it's alum: it's metal, and not SS).
Is there any
advantage to alum over plastic or vice-versa? I'm planning
on replacing it
with a bigger one, and first I thought plastic, but should
I consider
aluminum instead? I've always disliked the "plastic" taste
in the water
from a plastic tank.


you still have 'plastic' lines, don't you?

Scotty

An aluminum tank will be attacked by any chlorine in the water, plus
you 'really' need to install a magnesium removeable anode.

The chlorine attack will prevent you from chlore shock sanitization
and/or keeping a small concentration of chlorine to keep down the
growth of fungals and bacteria.

The BEST probable solution is to use aluminum (with baffles) and then
put an FDA/NSF approved 'lining epoxy' on the inside to render the tank
safe for chlorination, etc. Such lining epoxied can be applied with a
roller and brush (after sanding, etc. to make the aluminum 'bright').
Youll want: rated for POTABLE water and has the FDA/NSF
'certifications'; if you use 'common' epoxy you will get a high
concentration of 'leachables' in the water. This stuff is pretty
easy to 'roll-on'.
Do websearch for NSP-120 or go to the 'commercial' division of Interlux.
Such tank 'lining' in the marine and transportation industry is quite
common.
The advantage of lining a metal tank is that the tanki can have BAFFLES
which is impossible with a roto-molded 'plastic' tank.

On Oct 8, 11:19 am, Rich Hampel wrote:
An aluminum tank will be attacked by any chlorine in the water, plus
you 'really' need to install a magnesium removeable anode.

The chlorine attack will prevent you from chlore shock sanitization
and/or keeping a small concentration of chlorine to keep down the
growth of fungals and bacteria.

The BEST probable solution is to use aluminum (with baffles) and then
put an FDA/NSF approved 'lining epoxy' on the inside to render the tank
safe for chlorination, etc. Such lining epoxied can be applied with a
roller and brush (after sanding, etc. to make the aluminum 'bright').
Youll want: rated for POTABLE water and has the FDA/NSF
'certifications'; if you use 'common' epoxy you will get a high
concentration of 'leachables' in the water. This stuff is pretty
easy to 'roll-on'.
Do websearch for NSP-120 or go to the 'commercial' division of Interlux.
Such tank 'lining' in the marine and transportation industry is quite
common.
The advantage of lining a metal tank is that the tanki can have BAFFLES
which is impossible with a roto-molded 'plastic' tank.

problem is on a normal baffeled tank of any size (under the size a man
can crawl thru the baffles) is painting it with a brush or roller is
next to impossiable, unless the tank has an inspection/work port in
every space between baffles. It's a great way to go if your building
tanks but expensive to do right. And roto mold tanks can and do have
baffles. They are made by molding deep V's into the sides of the
tanks.

Joe

On Oct 2, 12:40 pm, druid wrote:
Hi,

I've always seen plastic watertanks, but the boat I'm buying has an old
aluminum one (I think it's alum: it's metal, and not SS). Is there any
advantage to alum over plastic or vice-versa?

Hi

I worked in a university research oyster hatchery as a bio lab aid. I
was the summer help. But the people who worked there were all PhD
types. I scrubbed glass wear. One of the things the lab did was test
hatchery materials and water supply materials for toxicity. We used
oyster larvae for the indicator in the bio assays. Basically,
fertilize the gametes in water with a test material. Observe the
development over time. Different materials kill/deform baby oysters at
different rates.

What I learned in two summers. Oysters are very sensitive creatures.
Just about anything will kill em. A material must be really inert
(safe) for an oyster to like it. For example, 316 L. Copper, on the
other hand, is death to an oyster. Do a little research regarding
effects of Aluminum on our brain. So goes with many plastics.

Ya Ya Ya yada yada yada in know now all the republicans o, and our one
libertarian will pipe in and say you'd have to eat a pound a day for
50 years to have any deleterious effect. So go for it.................

I had two 1979 Al tanks on my boat when I bought it. After yanking
both out and tearing one open I found pitting every where. Looked like
the pox. I eye estimate that 30-40% of all inside tank surfaces were
pitted and 100% surface was rough. Then I wondered where all that
material went????????????

Now I have two tanks on board. One 40 gallon and one 20 gallon. Both
are made of 316 L.

Forget plastic and forget Al...................
Some things ya just cant filter out using charcoal and paper.

Besides, its a boat. Why even conseder anything but the best.

Live long and prosper,
Bob

In article . com,
says...
On Oct 2, 12:40 pm, druid wrote:
Hi,

I've always seen plastic watertanks, but the boat I'm buying has an old
aluminum one (I think it's alum: it's metal, and not SS). Is there any
advantage to alum over plastic or vice-versa?

Hi

I worked in a university research oyster hatchery as a bio lab aid. I
was the summer help. But the people who worked there were all PhD
types. I scrubbed glass wear. One of the things the lab did was test
hatchery materials and water supply materials for toxicity. We used
oyster larvae for the indicator in the bio assays. Basically,
fertilize the gametes in water with a test material. Observe the
development over time. Different materials kill/deform baby oysters at
different rates.

What I learned in two summers. Oysters are very sensitive creatures.
Just about anything will kill em. A material must be really inert
(safe) for an oyster to like it. For example, 316 L. Copper, on the
other hand, is death to an oyster. Do a little research regarding
effects of Aluminum on our brain. So goes with many plastics.

That seems to be an apples and oranges comparison to me. Do you
have specific data on plastics? I drink a few liters of soda a
week from plastic bottles---and I can still type this with two
hands at age 61.

Ya Ya Ya yada yada yada in know now all the republicans o, and our one
libertarian will pipe in and say you'd have to eat a pound a day for
50 years to have any deleterious effect. So go for it.................

I had two 1979 Al tanks on my boat when I bought it. After yanking
both out and tearing one open I found pitting every where. Looked like
the pox. I eye estimate that 30-40% of all inside tank surfaces were
pitted and 100% surface was rough. Then I wondered where all that
material went????????????

"all that material" might have been two to three grams of aluminum in a
few thousand kilograms of water. Since the aluminum content of the
water put into the tank was probably 1 to 8PPM, that doesn't
sound like a problem unless you left the original 100 gallons
of water in the tank for 10 to 15 years.

Now I have two tanks on board. One 40 gallon and one 20 gallon. Both
are made of 316 L.

Forget plastic and forget Al...................
Some things ya just cant filter out using charcoal and paper.

Besides, its a boat. Why even conseder anything but the best.

Um, weight and cost probably lead the list. If your boating
budget is unlimited, you've got more money than me.

Worrying about aluminum tanks in a boat where you fill the
tank from a city water supply that uses aluminum sulfate
as a coagulant seems a waste of time to me.

Live long and prosper,
Bob


Mark Borgerson