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From: (no name) (no email)
Date: Fri Dec 19 2003 - 10:52:18 EST
This is an educational message only from the marine survey "Boatpokers"
net; strictly for learning from a professional discussion concerning
adding fuel tanks:
--------- Forwarded message ----------
From: "J. G. Merritt" <>
To: <>
Cc: <>
Date: Thu, 18 Dec 2003 19:50:08 -0600
Subject: Re: [Boatpokers] Pacific Skiffs Fuel Odor
Message-ID: <050001c3c5d2$707844c0$6401a8c0 at d6gg7621>
References: <6C56E43C dot 0F247F76 dot 0004909B at aol dot com>
Jim,
It's hard to compile responses when you don't get any to compile! Sort
of
like the woodchuck bit.
You did not mention where the fuel compartments are located, I sort of
thought they would be in the consoles but the rest of your text did not
indicate a console type installation. Polyethylene tanks do have some
permeation problems, closely specified in the regulations and supposedly
adhered to by the tank manufacturer. That's why you need the label, to
find
the manufacturer. All such tanks expand a considerable bit the first
time
they are filled, the expansion is permanent and the boat builder has to
make
allowance for it in chocking or strapping the tanks in place. That could
be
one source of a leak if the tank moved and partially loosened or
separated
fill, vent , or withdrawal tube fittings.
Another possibility is a simple overfilling and improper routing of
spilled
fuel that allowed it to get into interior spaces with no ventilation or
clear drainage channels. Your nose is more sensitive to gasoline fumes
than
any electronic unit and may well be detecting an odor that is noticeable
but
is neither fresh or a hazard. Suggest a thorough fresh water washdown
and
checking afterwards for any remaining scent. Another suggestion is a
full
pressure test of the complete system including the hose(s) to the
engine(s) - 3 psi and holding the pressure for 5 minutes with 0 drop plus
test of all joints with a suitable liquid solution while the pressure is
applied.
Your concerns are valid and your nose is telling you something that
should
not be ignored. Find the source and cure the problem, just hope it's
only a
matter of cleaning. Once past the initial fuel absorption and swelling
process the tanks should not pass any detectable vapor. Shouldn't pass
any
before then but it seems they do.
Other noted failure modes I have encountered in the past: If a tapered
pipe
fitting is overtightened it creates radial splits in the tank from the
pressure, hard to detect in tight places. If Teflon tape is used for
thread
sealer on pipe threads it will almost invariably leak, particularly if
disturbed in the least amount. The stuff just doesn't make a gas proof
seal. Non hardening Permatex or equal should be used on all threaded
fittings where a seal is needed.
Any builder today that does not double clamp fill hoses or install tanks
with legible labels obviously needs a visit from a USCG compliance
official.
Best regards,
Jim Merritt AMS
----- Original Message -----
From: <>
To: <>
Sent: Wednesday, December 17, 2003 1:12 PM
Subject: [Boatpokers] Pacific Skiffs Fuel Odor
> Greetings from flu-ravaged Southeast Alaska:
>
> Recently surveyed several boats for NMFS. Two of the boats were
recently
built 2002 Pacific 2025V and 2003 Pacific 17. These boats are beefy,
aluminum welded commercial grade skiffs with center consoles. Welds and
workmanship are quite good. Boats are quite expensive as equipped.
>
> Of course there is little to no access to interior, especially to the
fuel
tank compartment. Both boats had single clamped fuel filler hoses and
the
20' boat had no label that I could see on the "rotational polyethylene
molded fuel tank". The 17' boat had a label.
>
> In both surveys, as I walked up to each vessel, I could smell gasoline.
Opening the inspection plate in the deck shows limited access to the fuel
fill, vent, and sender. All fittings were snug (although as mentioned
the
filler was only single clamped). Sticking your nose next to the access
reveals the odor of gasoline.
>
> I checked USCG recall site and there are none. I called the builder
who
proceeded to tell me that these "rotational molded tanks" are preferred
by
the Coast Guard and the tanks do permeate a gasoline odor. And, that
there
are no ignition sources in the tank compartment (true). Both boats have
Yamaha outboards.
>
> Anyone familiar with the odor permeating qualities of these tanks and
is
this a safety issue? My gut feel is that something is wrong here.
>
> I will compile all responses.
>
> Thanks,
>
> Jim Sepel, AMS 315
> Juneau, AK
> 907-790-2628
> _______________________________________________
> Boatpokers mailing list
>
> http://marinesurveyor.cis.to/mailman/listinfo/boatpokers
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