Glenn Ashmore wrote:
I am beginning to wonder if locally built aluminum tanks are a good
idea. Every shop around here is tooled up for 6061 but marine tanks
need to be 5000 series. I will have to supply my own 5086 and TIG
welding rod and the best price I can find is in New Orleans. $130 a
4x10 sheet plus about $100 shipping. Still, a lot better than $300 a
sheet in Atlanta but not as good as $65/sheet for 1018 mild steel locally.

If I go with aluminum I think I will have to machine my own fittings.
There are very few sources of 5000 series aluminum fittings and the
selection is limited. It will be fairly simple to mill and tap some
NPTF fittings from 1" round for welding onto the tank.

I would like to hear some discussion of mild steel vs aluminum. Total
cost of mild steel tanks is about half that of aluminum but weighs about
twice as much. In this case a pair of custom 40 gallon would cost $600
in aluminum with some effort on my part to get the alloy vs $320 for
mild steel and weigh 72 pounds vs 125 for steel. From what I hear, a
well painted and installed steel tank will last just as long as
aluminum. Longer if the aluminum is not properly installed.

Ron White wrote:

I had my aluminum gasoline tanks built by Ezell Industries one of the
three
marine tank builders in Perry Fl. I let them decide where the baffles
were
( a wise move) also they provided the tank fitting and valves which
some of
need to be al. rather than ss or brass. One thing to consider also is the
pickup tubes, they made these with nylon? tubing swaged onto the al
tank top
fittings. Some other people I talked to were not up to speed on the
issue of
not using metal pickup tubes as they are subject to vibration and
fatigue.
Wouldn't want the pickup to break!!! I was very happy with Ezell and the
good work they did.
Then Painting, which I did. This system is my standard and I use it on
any
alum. thing I make for boats.
1, clean with acid ectching solution ( like, Ditzler DX533)
2 prime with dupont Variprime 615S self etching primer.
3 finish with several coats of 2 part epoxy primer.
For exposed alum. things, add about three finish coats of a urethane
enhanced enamel like Limco 1234.
All of the products are availble from automotive distributers I think the
key is using the variprime as is bonds to aluminum like nothing else I
know
of..



Either aluminum or steel will probably outlast both you and me. I've
seen diesel tanks for equipment on trucks made from steel that have
never been painted that were over 30 years old. I'm thinking about
making mine out of steel, but I plan on some type of coating inside and
out, just not sure what brand yet. Weight is no problem for me with a
steel boat and no plans for racing, just cruising. I would think that
would be a major deciding factor for you. Can you stand the weight.
Cost is always a major deciding factor for me. I have to build on the
cheap. I would think you would have more resources available. Is $300
or $400 a deciding factor? What about a poly tank? I'm sure you've
priced those, about the same as aluminum, but they're ready built.

Good Luck,

Donald

--
I'm building a Steel Robert's 434. You can sneak a peek if you wish by
clicking on me link below.
http://bellsouthpwp.net/d/o/donrayp/
'USA, Home of the best
politicians money can buy'

Donald Phillips wrote:

Either aluminum or steel will probably outlast both you and me. I've
seen diesel tanks for equipment on trucks made from steel that have
never been painted that were over 30 years old. I'm thinking about
making mine out of steel, but I plan on some type of coating inside and
out, just not sure what brand yet. Weight is no problem for me with a
steel boat and no plans for racing, just cruising. I would think that
would be a major deciding factor for you. Can you stand the weight.
Cost is always a major deciding factor for me. I have to build on the
cheap. I would think you would have more resources available. Is $300
or $400 a deciding factor? What about a poly tank? I'm sure you've
priced those, about the same as aluminum, but they're ready built.

I don't think interior coatings on diesel tanks are a good idea. Diesel
is not going to attack the metal and is a pretty good corrosion
preventive. Any coating carries the possibility of flaking off and
finding its way into the filters.

$300 would not be a deciding factor but now that I am on the down hill
side of the project I find Everett Dirksen's comment about "A billion
here, a billion there, pretty soon we are talking real money."
particularly relevent. :-)

I checked every maker of poly tanks but could not find a shape that
would work without wasting a lot of space or leaving the COG of the fuel
way to high and getting molds made for custom tanks is way to expensive.

I considered building my own out of glass/epoxy but I don't like the
risk. I built two water tanks and found it took a lot of effort to get
really solid laminations in the corners. If there is even one pin hole
there will be some weeping. I can live with a little fresh water
weeping but not diesel.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

Did you check Ronco for a tank? They make more stock shapes than anyone I
know, and are very easy to work with. http://www.ronco-plastics.com/.

I'd stick with regular steel for the tanks if you can't find one at Ronco. I
have a pair that are 17 yrs. old and fine. You are right about the inside,
the diesel is a good anticorrosion treatment, as long as you keep the water
out. The outside should be painted with a good coating of some kind, and the
bottom should be supported so that air can circulate under it. Obviously,
you've got to keep the water off the top of the tank as well. Be sure to
have the maker put a sump with a dip tube from the top in the tank so you
can suck out any water that might end up in there.

"Glenn Ashmore" wrote in message
news:EoRjb.78877$sp2.14422@lakeread04...

Donald Phillips wrote:

Either aluminum or steel will probably outlast both you and me. I've
seen diesel tanks for equipment on trucks made from steel that have
never been painted that were over 30 years old. I'm thinking about
making mine out of steel, but I plan on some type of coating inside and
out, just not sure what brand yet. Weight is no problem for me with a
steel boat and no plans for racing, just cruising. I would think that
would be a major deciding factor for you. Can you stand the weight.
Cost is always a major deciding factor for me. I have to build on the
cheap. I would think you would have more resources available. Is $300
or $400 a deciding factor? What about a poly tank? I'm sure you've
priced those, about the same as aluminum, but they're ready built.

I don't think interior coatings on diesel tanks are a good idea. Diesel
is not going to attack the metal and is a pretty good corrosion
preventive. Any coating carries the possibility of flaking off and
finding its way into the filters.

$300 would not be a deciding factor but now that I am on the down hill
side of the project I find Everett Dirksen's comment about "A billion
here, a billion there, pretty soon we are talking real money."
particularly relevent. :-)

I checked every maker of poly tanks but could not find a shape that
would work without wasting a lot of space or leaving the COG of the fuel
way to high and getting molds made for custom tanks is way to expensive.

I considered building my own out of glass/epoxy but I don't like the
risk. I built two water tanks and found it took a lot of effort to get
really solid laminations in the corners. If there is even one pin hole
there will be some weeping. I can live with a little fresh water
weeping but not diesel.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

Keith wrote:
Did you check Ronco for a tank? They make more stock shapes than anyone I
know, and are very easy to work with. http://www.ronco-plastics.com/.

My holding tanks are Roncos. No question that Ronco has the best
selection and best quality but the last time I checked they only build
water and holding tanks. HDPE is fine for water and holding but not for
diesel. They do use cross linked PE in their industrial chemical line
but for some reason they don't want to use it in their marine line.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

OK, Check with Ezell Industies Perry Fl. they made my tanks with 5052 H2 and
they were beautifuily done. Mine were 100 gallon but the prices you
mentioned should no problem not that money makes any difference. phone 850
578-2558 Dave Miller
Try also Rds Mfg also in Perry 850 584-6898
no personal experience with Rds but they make for some nice boats I have
been on.
Get some pro help here and move on to some good stuff like sanding and
grinding. I do hope you take take my advise on priming first with self
etching primer! The dupont Variprime has chromates as well, good for you
too.

--
Ron White
my boatbuilding web site is:
www.concentric.net/~knotreel

Keith wrote:

Did you check Ronco for a tank? They make more stock shapes than anyone I
know, and are very easy to work with. http://www.ronco-plastics.com/.

I'd stick with regular steel for the tanks if you can't find one at Ronco. I
have a pair that are 17 yrs. old and fine. You are right about the inside,
the diesel is a good anticorrosion treatment, as long as you keep the water
out. The outside should be painted with a good coating of some kind, and the
bottom should be supported so that air can circulate under it. Obviously,
you've got to keep the water off the top of the tank as well. Be sure to
have the maker put a sump with a dip tube from the top in the tank so you
can suck out any water that might end up in there.

In a sailboat, maximizing tank size is going to result in an irregular shape
with the fuel pick up at the deepest point. A sump is an unnecessary
embelishment. Water is going to be of concern only with contaminated
supply in a well designed system. If water in the fuel causes sleepless
nights tee into the fuel pump discharge so a liter or so can be pumped
into a container for disposal.

On Sat, 18 Oct 2003 12:39:43 -0700, w kensit
wrote:


In a sailboat, maximizing tank size is going to result in an irregular shape
with the fuel pick up at the deepest point. A sump is an unnecessary
embelishment. Water is going to be of concern only with contaminated
supply in a well designed system. If water in the fuel causes sleepless
nights tee into the fuel pump discharge so a liter or so can be pumped
into a container for disposal.

Disagree. Tanks that are less than completely full condense water
during thermal cycles, and water being heavier than gas or diesel, it
collects at the low point. This really ought to be a small sump, need
not be more than a tea cup - where it can be checked via a sampler.
Nothing stops an engine better than water in the fuel.

Brian Whatcott Altus OK

Brian Whatcott wrote:

On Sat, 18 Oct 2003 12:39:43 -0700, w kensit
wrote:



In a sailboat, maximizing tank size is going to result in an irregular shape
with the fuel pick up at the deepest point. A sump is an unnecessary
embelishment. Water is going to be of concern only with contaminated
supply in a well designed system. If water in the fuel causes sleepless
nights tee into the fuel pump discharge so a liter or so can be pumped
into a container for disposal.


Disagree. Tanks that are less than completely full condense water
during thermal cycles, and water being heavier than gas or diesel, it
collects at the low point. This really ought to be a small sump, need
not be more than a tea cup - where it can be checked via a sampler.
Nothing stops an engine better than water in the fuel.

Brian Whatcott Altus OK

Which all the more reason to end the season with full tanks. The only
time I experienced problems was from a load of contaminated fuel in mid
summer. My point is that unless your tank has a large flat bottom you
are in fact adding a sump to a sump.

Brian Whatcott wrote in message . ..
On Sat, 18 Oct 2003 12:39:43 -0700, w kensit
wrote:
....
Nothing stops an engine better than water in the fuel.

Other than me putting a wrench on it! Scotty