Why so all this speculation? Talk to someone who makes tanks, then
follow their advise.

I had aluminum diesel tanks made at Pipe Works, in Long Beach, Ca. They
know what they are doing.
Jim

Wayne.B wrote:

If everything goes according to plan, I'm about to buy a Grand Banks
49 trawler that needs new fuel tanks (500 gallons each).

Any thoughts from this group on the best material for new tanks,
fabrication hints, and/or removal/installation suggestions?

On Sun, 06 Jun 2004 03:18:33 GMT, Jim wrote:

Why so all this speculation? Talk to someone who makes tanks, then
follow their advise.

=================================

There are a lot of different views and issues out there and I'd like
to get a sampling of that before making a decision. Most tank makers
will just go with what they know, not necessarily the latest thinking
or best approach. This is a big decision which will impact the future
relibility and resale value of the boat, and also involves major $$$s.

"Steve Lusardi" wrote in message
...
Wayne, you are talking about a reasonable effort and significant cost
regardless of the material chosen, Do not use aluminum, it is far too
reactive. Do not use gavanized steel. The diesel will disolve the zinc.
The
ultimate material should be 316TI SS and next best would be mild steel
blasted and painted with the special Permatex tank paint. This paint is
designed for large storage tanks and must be ordered specially. I just
finished 2 water tanks slightly smaller than yours in stainless and the
material cost was $3200 and that included access hatches.
Steve

Commercial small / medium size vessel practice is usually aluminum or mild
steel. I don't see using plastic tanks, the size you are suggesting is
pretty big for plastic of non cylindrical shapes.

Saying aluminum is "too reactive" isn't really true. The only problem with
aluminum is if the tank is let to sit with moisture trapped against it.
Stand-offs or similar methods to keep any condensation from the skin of the
tank is a good idea.

Mild steel is generally not painted inside and the steel tanks do last at
least 20 years (the diesel on the inside tends to give a nice coating).
That said you can coat the inside of steel tanks for additional protection.

No I wouldn't use stainless steel - generally weld cracking can occur with
the thin plates of tanks. If you do go S.S., I would probably select 316L,
which is a low carbon version of 316 that is suited for welding. Much
better for corrosion than 304. But it's a pretty big price premium for
doubtful benefit.


--
Evan Gatehouse

you'll have to rewrite my email address to get to me
ceilydh AT 3web dot net
(fools the spammers)

Wayne,
You must consider maintenance, so an access hatch will be needed for each
baffelled compartment. I use studs, nuts and make-a-gasket RTV for the seal.
The boat layout will determine where the inlet and outlet ports should be.
Here, I suggest flanges, studs and gaskets or RTV. When all assembled, test
at 2 psi for 24 hours. I take special care with dissimliar metals and if I
have to use them, I use nylon isolators and tophats around the bolts and
studs. Always check with a VOM to be sure. However, do not use these with
the fuel tank. (static). Dissimiliar metals only matter when wet. No water,
no ploblem. I would be concerned about chafe between the hull and the tank.
Either eliminate the problem by bolting hard to the hull or use rubber shock
mounts and use a bond cable across a mount for earth.
Steve

"Wayne.B" wrote in message
...
On Sat, 5 Jun 2004 19:47:57 +0200, "Steve Lusardi"
wrote:
As a cost, I would estimate $3000 to $4000 per tank would be
close.

Thanks for the information, estimates are close to what I've received.

The realy BIG costs are removal and re-installation - holes to be cut,
reglassed, painted, etc.

What do you use for fittings, and do you take special precautions to
isolate dis-similar metals?

Evan,
You are correct, but here is the rub. Diesel is hygroscopic and with tanks
this size water, being more dense than fuel oil, will settle at the bottom
and EAT the aluminum pretty damn quick.
Steve

"Evan Gatehouse" wrote in message
...

"Steve Lusardi" wrote in message
...
Wayne, you are talking about a reasonable effort and significant cost
regardless of the material chosen, Do not use aluminum, it is far too
reactive. Do not use gavanized steel. The diesel will disolve the zinc.
The
ultimate material should be 316TI SS and next best would be mild steel
blasted and painted with the special Permatex tank paint. This paint is
designed for large storage tanks and must be ordered specially. I just
finished 2 water tanks slightly smaller than yours in stainless and the
material cost was $3200 and that included access hatches.
Steve

Commercial small / medium size vessel practice is usually aluminum or mild
steel. I don't see using plastic tanks, the size you are suggesting is
pretty big for plastic of non cylindrical shapes.

Saying aluminum is "too reactive" isn't really true. The only problem
with
aluminum is if the tank is let to sit with moisture trapped against it.
Stand-offs or similar methods to keep any condensation from the skin of
the
tank is a good idea.

Mild steel is generally not painted inside and the steel tanks do last at
least 20 years (the diesel on the inside tends to give a nice coating).
That said you can coat the inside of steel tanks for additional
protection.

No I wouldn't use stainless steel - generally weld cracking can occur with
the thin plates of tanks. If you do go S.S., I would probably select
316L,
which is a low carbon version of 316 that is suited for welding. Much
better for corrosion than 304. But it's a pretty big price premium for
doubtful benefit.


--
Evan Gatehouse

you'll have to rewrite my email address to get to me
ceilydh AT 3web dot net
(fools the spammers)

Jim,
Think about your statement, Tanks, Long Beach, California, desert. Nothing
rusts in LA. Don't do it in Florida!
Steve
"Jim" wrote in message
ink.net...
Why so all this speculation? Talk to someone who makes tanks, then
follow their advise.

I had aluminum diesel tanks made at Pipe Works, in Long Beach, Ca. They
know what they are doing.
Jim

Wayne.B wrote:

If everything goes according to plan, I'm about to buy a Grand Banks
49 trawler that needs new fuel tanks (500 gallons each).

Any thoughts from this group on the best material for new tanks,
fabrication hints, and/or removal/installation suggestions?

The "latest thinking" can get you in trouble more often than the tried
and true. As Evan, who has worked for some major marine architects,
said, recreational and small commercial boats almost always use aluminum
or black iron. Properly installed they will last the life of the boat.

I would not go to your local welding shop but custom tank makers like
Ezell in Florida, Aftermarket in Louisiana and Luther's Welding in Rhode
Island make hundreds of aluminum tanks a year to higher than USCG specs.
They have been building tanks for a long time and know what they are
doing.

316TI is more commonly available in Europe but considered a specialty
steel in the US. (read EXPENSIVE) The only difference between 316L and
316TI is that the TI limits carbon displacement at high temperatures.
That maintains the corrosion resistance better in the welds but does not
prevent stress cracking. 316TI is specified for applications where the
temperatures regularly exceeds 800F. If your tank ever gets that hot
you have a lot more to worry about than stress cracking.

A 500 gallon tank is WAY to big to be built in welded or even rotomolded
poly. Once you get larger than about 70 gallons they are almost always
cylindrical. Above about 250 gallons they are vertical cylinders like
farm storage tanks.

Wayne.B wrote:

There are a lot of different views and issues out there and I'd like
to get a sampling of that before making a decision. Most tank makers
will just go with what they know, not necessarily the latest thinking
or best approach. This is a big decision which will impact the future
relibility and resale value of the boat, and also involves major $$$s.


--
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

On Sunday 06 June 2004 11:51 am in rec.boats.building Steve Lusardi wrote:

Wayne,
You must consider maintenance, so an access hatch will be needed for each
baffelled compartment. I use studs, nuts and make-a-gasket RTV for the
seal. The boat layout will determine where the inlet and outlet ports
should be. Here, I suggest flanges, studs and gaskets or RTV. When all
assembled, test at 2 psi for 24 hours. I take special care with dissimliar
metals and if I have to use them, I use nylon isolators and tophats around
the bolts and studs. Always check with a VOM to be sure. However, do not
use these with the fuel tank. (static). Dissimiliar metals only matter
when wet. No water, no ploblem. I would be concerned about chafe between
the hull and the tank. Either eliminate the problem by bolting hard to the
hull or use rubber shock mounts and use a bond cable across a mount for
earth. Steve

All good stuff, but one additional point :=
Each tank should have a bottom drain at the lowest point. Water
contamination is a common problem for most fuels, especially diesel.
Water will always settle to the bottom of the tank, it is a good idea
to wait overnight after refueling to allow any water to separate and
then drain the tank bottom until clean fuel comes out.
It is also good practice to also do this as a regular routine inspection
to prevent the buildup of condensation or inward leakage from vents and
fillers.

--
My real address is crn (at) netunix (dot) com
WARNING all messages containing attachments or html will be silently
deleted. Send only plain text.

Glenn is correct, there are many people that make fuel and even water tanks
in Alu, but we all have predjudices and personnel favorites. Personnally, I
make diesel tanks in mild steel, Water tanks in 316TI. Yes, in Europe 316TI
is the same price as 316L. The major use in Europe of TI is not high
temperature applications, it is food processing vats, because it resists
acids better than L . I believe that most high temperature applications use
inconel, not 316. But be that as it may, this thread has exposed all the
available solutions and pitfalls for the audiance and that is what this NG
is all about.
Steve

"Glenn Ashmore" wrote in message
news:tVCwc.23786$My6.15959@fed1read05...
The "latest thinking" can get you in trouble more often than the tried
and true. As Evan, who has worked for some major marine architects,
said, recreational and small commercial boats almost always use aluminum
or black iron. Properly installed they will last the life of the boat.

I would not go to your local welding shop but custom tank makers like
Ezell in Florida, Aftermarket in Louisiana and Luther's Welding in Rhode
Island make hundreds of aluminum tanks a year to higher than USCG specs.
They have been building tanks for a long time and know what they are
doing.

316TI is more commonly available in Europe but considered a specialty
steel in the US. (read EXPENSIVE) The only difference between 316L and
316TI is that the TI limits carbon displacement at high temperatures.
That maintains the corrosion resistance better in the welds but does not
prevent stress cracking. 316TI is specified for applications where the
temperatures regularly exceeds 800F. If your tank ever gets that hot
you have a lot more to worry about than stress cracking.

A 500 gallon tank is WAY to big to be built in welded or even rotomolded
poly. Once you get larger than about 70 gallons they are almost always
cylindrical. Above about 250 gallons they are vertical cylinders like
farm storage tanks.

Wayne.B wrote:

There are a lot of different views and issues out there and I'd like
to get a sampling of that before making a decision. Most tank makers
will just go with what they know, not necessarily the latest thinking
or best approach. This is a big decision which will impact the future
relibility and resale value of the boat, and also involves major $$$s.


--
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

The concept I'm advocating is following the advise of experienced tank
makers who know how to build to specifications and standards. And stand
behind their work.

I'm not advocating any specific material. I'd talk to a half dozen
builders with experience and see if they agree on material and
construction. (They do, by the way).

Jim

Steve Lusardi wrote:
Jim,
Think about your statement, Tanks, Long Beach, California, desert. Nothing
rusts in LA. Don't do it in Florida!
Steve
"Jim" wrote in message
ink.net...

Why so all this speculation? Talk to someone who makes tanks, then
follow their advise.

I had aluminum diesel tanks made at Pipe Works, in Long Beach, Ca. They
know what they are doing.
Jim

Wayne.B wrote:


If everything goes according to plan, I'm about to buy a Grand Banks
49 trawler that needs new fuel tanks (500 gallons each).

Any thoughts from this group on the best material for new tanks,
fabrication hints, and/or removal/installation suggestions?