I have a 31 aluminum work boat with an under deck fuel tank which must be
leaking. The aluminum deck is welded in place. The tank is a 100 gallon
aluminum tank. The boat is only 1 year old. I removed the drain plug from
the back of the boat and about 2 gaollons of gas came out, this leads me to
believe that the crack must be on the top of the tank because the tank is
almost full and this is the only time I ever opened the drain plug. Before I
do any work I want to make sure I don't have an explosion. If I fill the
bilge area with dishsoap and water and then drain it will this remove all
dangerous vapours? Any other ideas?

Sounds like you have a dangerous situation.

Your bilge blower should be set up to ventilate all the bilge areas. If not
then the vent system wasn't installed properly.

I would recommend that you not only wash it down good but you should rig
some gasoline safe ventilation to run until it is safe. If there is going to
be any welding or spark producing work done to get to the tank (defuel the
tank), you should have it tested as 'safe for hot work' by a qualified
person. If it is in a commercial yard they my require this as well.

Steve
s/v Good Intentions

Or maybe the problem is the filler tube (maybe torn) or it's connection to
the tank (loose clamp)? And might I suggest you remove ALL the fuel from the
boat (tank, bilge) before doing any work ... I assume by work you mean
cutting open the deck ... and let it air out for a coupla days before doing
any work.

habbi wrote in message
...
I have a 31 aluminum work boat with an under deck fuel tank which must be
leaking. The aluminum deck is welded in place. The tank is a 100 gallon
aluminum tank. The boat is only 1 year old. I removed the drain plug from
the back of the boat and about 2 gaollons of gas came out, this leads me
to
believe that the crack must be on the top of the tank because the tank is
almost full and this is the only time I ever opened the drain plug. Before
I
do any work I want to make sure I don't have an explosion. If I fill the
bilge area with dishsoap and water and then drain it will this remove all
dangerous vapours? Any other ideas?

The aluminum tank has aluminum pipes welded to it which go toward the side
of the hull and then 90 up 1' above the deck.(welded through deck.) Then the
rubber filler, vent and feed start. I plugged the filler and vent and then
pressurized the feed with 5psi. The air is hissing out of the tank but I
can't see where. Bottom line is the deck has to be cut open but I want the
vapours gone before attempting this. I have heard of people rinsing out
metal gas tanks from cars with water and then trying to weld them and they
still blew up. I guess what I am essentially dealing with is a very very
large empty gasoline tank which has a smaller 100 gallon gasoline tank
inside it.
What should expect from the builder which is in a different province and had
the boat shipped here. Should this type of problem be their responsibility
or mine? Again the boat is 1 year old.

"Bowgus" wrote in message
.cable.rogers.com...
Or maybe the problem is the filler tube (maybe torn) or it's connection to
the tank (loose clamp)? And might I suggest you remove ALL the fuel from
the
boat (tank, bilge) before doing any work ... I assume by work you mean
cutting open the deck ... and let it air out for a coupla days before
doing
any work.

habbi wrote in message
...
I have a 31 aluminum work boat with an under deck fuel tank which must
be
leaking. The aluminum deck is welded in place. The tank is a 100 gallon
aluminum tank. The boat is only 1 year old. I removed the drain plug
from
the back of the boat and about 2 gaollons of gas came out, this leads me
to
believe that the crack must be on the top of the tank because the tank
is
almost full and this is the only time I ever opened the drain plug.
Before
I
do any work I want to make sure I don't have an explosion. If I fill the
bilge area with dishsoap and water and then drain it will this remove
all
dangerous vapours? Any other ideas?

washing and letting it vent will probably not work.

BE SURE TO INFORM SERVICE PERSONAL OF THE FORMER PRESENCE OF GASOLINE.
Otherwise you may face a costly lawsuit for wrongful death.

Only way to weld it is to leave it filled with water which will displace any
air needed to create an explosion.

Best practice for DIY tank repair in 4x4ing is to flush the tank
several times then do any welding with the tank full of water, as in
right to the top of the filler and vent, zero air inside, period. Then
weld.

Yes, I have done this to my Toyota 4x4 while on a trail.

Insert disclaimer here...

Gas is explosive in confined areas and the water will displace the
oxygen preventing an explosion. If you can do likewise with the bilge,
flushing and filling, you should be relatively safe. I would also use
a reciprocating saw or some form of blade cutting that is less likely
to cause sparks as opposed to a die grinder or torch.

As for responsibility, you purchased a working vessel, fit and ready
for service. The onus is on the supplier to stand behind workmanship;
unless the boat was in some form of distress at some point I can see
no reason for a fuel leak, ergo workmanship.


On Wed, 07 Apr 2004 00:41:08 GMT, "habbi"
wrote:

The aluminum tank has aluminum pipes welded to it which go toward the side
of the hull and then 90 up 1' above the deck.(welded through deck.) Then the
rubber filler, vent and feed start. I plugged the filler and vent and then
pressurized the feed with 5psi. The air is hissing out of the tank but I
can't see where. Bottom line is the deck has to be cut open but I want the
vapours gone before attempting this. I have heard of people rinsing out
metal gas tanks from cars with water and then trying to weld them and they
still blew up. I guess what I am essentially dealing with is a very very
large empty gasoline tank which has a smaller 100 gallon gasoline tank
inside it.
What should expect from the builder which is in a different province and had
the boat shipped here. Should this type of problem be their responsibility
or mine? Again the boat is 1 year old.

"Bowgus" wrote in message
t.cable.rogers.com...
Or maybe the problem is the filler tube (maybe torn) or it's connection to
the tank (loose clamp)? And might I suggest you remove ALL the fuel from
the
boat (tank, bilge) before doing any work ... I assume by work you mean
cutting open the deck ... and let it air out for a coupla days before
doing
any work.

habbi wrote in message
...
I have a 31 aluminum work boat with an under deck fuel tank which must
be
leaking. The aluminum deck is welded in place. The tank is a 100 gallon
aluminum tank. The boat is only 1 year old. I removed the drain plug
from
the back of the boat and about 2 gaollons of gas came out, this leads me
to
believe that the crack must be on the top of the tank because the tank
is
almost full and this is the only time I ever opened the drain plug.
Before
I
do any work I want to make sure I don't have an explosion. If I fill the
bilge area with dishsoap and water and then drain it will this remove
all
dangerous vapours? Any other ideas?

The gas tank, to do it properly, needs to be emptied, cleaned by several
rinses and then inerted with gas while it is being welded. Your welder will
have a procedure for this.. His inerting gas must be what ever is suitable
for aluminum welding (mig or tig).

Cleaning and gas freeing the tank is a small problem. It would be the gas
freeing of the bilges that concerns me since it sounds like you have to do
some cutting to get into them and the tank.

You ask about builders responsibility.. I would say yes, but you would have
a hard time getting him to do anything if you can't take it to his
facility... He's not going to want to pay for the gas free and welders
services in someone elses boat yard..

In the typical US boat yard, your talking about several thousand even if
everything were simple.. It cost money to have a job like this done
correctly and safely..

Steve
s/v Good Intentions

Find a shop that does aluminum boat and fuel tank repair and leave it up to
them. rec.boats.building is fine for discussion, but I'd seriously consider
a more prudent approach to your tank repair problem.

As far as who's responsible, it comes down to warranty. If you have it then
fine, but it sounds like you don't, else you'd know, right? As far as law
goes, well ...it's a reasonable expectation that the tank does not leak,
assuming the boat was new. Have your attorney write a letter...

--
http://www.advantagecomposites.com/tongass -- My 22' Tolman Skiff project
http://www.advantagecomposites.com/catalog -- Discounted System Three
Resins products


"Steve" wrote in message
...
The gas tank, to do it properly, needs to be emptied, cleaned by several
rinses and then inerted with gas while it is being welded. Your welder
will
have a procedure for this.. His inerting gas must be what ever is suitable
for aluminum welding (mig or tig).

Cleaning and gas freeing the tank is a small problem. It would be the gas
freeing of the bilges that concerns me since it sounds like you have to do
some cutting to get into them and the tank.

You ask about builders responsibility.. I would say yes, but you would
have
a hard time getting him to do anything if you can't take it to his
facility... He's not going to want to pay for the gas free and welders
services in someone elses boat yard..

In the typical US boat yard, your talking about several thousand even if
everything were simple.. It cost money to have a job like this done
correctly and safely..

Steve
s/v Good Intentions

Funny, but warranties only serve to limit liability. You have the best
warranty when there isn't one in writing. Fitness for use is a robust
concept. I'd say the builder is liable and should fix the thing. Getting
them to do it may take some legal action though. Try giving them a call and
see what happens.

--


Keith
__
Don't let your mind wander -- it's too little to be let out alone.
"Brian D" wrote in message
news:VDJcc.86505$JO3.44526@attbi_s04...
Find a shop that does aluminum boat and fuel tank repair and leave it up
to
them. rec.boats.building is fine for discussion, but I'd seriously
consider
a more prudent approach to your tank repair problem.

As far as who's responsible, it comes down to warranty. If you have it
then
fine, but it sounds like you don't, else you'd know, right? As far as law
goes, well ...it's a reasonable expectation that the tank does not leak,
assuming the boat was new. Have your attorney write a letter...

--
http://www.advantagecomposites.com/tongass -- My 22' Tolman Skiff
project
http://www.advantagecomposites.com/catalog -- Discounted System Three
Resins products


"Steve" wrote in message
...
The gas tank, to do it properly, needs to be emptied, cleaned by several
rinses and then inerted with gas while it is being welded. Your welder
will
have a procedure for this.. His inerting gas must be what ever is
suitable
for aluminum welding (mig or tig).

Cleaning and gas freeing the tank is a small problem. It would be the
gas
freeing of the bilges that concerns me since it sounds like you have to
do
some cutting to get into them and the tank.

You ask about builders responsibility.. I would say yes, but you would
have
a hard time getting him to do anything if you can't take it to his
facility... He's not going to want to pay for the gas free and welders
services in someone elses boat yard..

In the typical US boat yard, your talking about several thousand even if
everything were simple.. It cost money to have a job like this done
correctly and safely..

Steve
s/v Good Intentions

Some thoughts.
Check with the builder before you do anything. Unless you bought a
one-off, there may be a generic problem and a generic solution. You
won't know unless you ask.
It's human nature to assume the worst, but a lot of leaks are simple
things we've overlooked. Are you sure there's no other mechanical
fitting that could have become loose--cleanout, drain plug, sensor or gauge?
No matter how well you sanitize the bilge and tank, keep ventilation
running at least an hour before you cut or flood with CO2. 5 or 10#s of
dry ice between the bilge and tank ought to do it.
You can rent an explosive atmosphere tester at a tool rental store.
If you have to cut through the deck to get to the tank, consider adding
a permanent access. Lightening never strikes twice in the same
spot...or does it? Same goes for the tank. If practicable, leave a
manhole in the top of the tank under the accessway. A low flanged
collar with thick fuel-friendly gasket and bolt-on cover is the way to
go. With the collar flange up, nuts and bolts are always on the outside
of the tank. Don't goof around with saddle patches and self-tapping
screws, you'll just have to come back next year and do it right.
And most important, if you don't have the expertise and equipment for
welding aluminum, have a qualified shop do the work, you'll save money
in the end. Good luck.