fibreglass hull bilge
 

Hi

I have just got my first fibreglass hulled boat (14 FOOT HALF CAB) and it
appears to have a large leak into the underfloor bilge. After about 4 hours
on the water I have about 4 gallons or more of seawater come out of the
bungs. I have looked under the boat and beyond normal looking scratches in
the gelcoat the only breaches of hull integrity are the front metal centre
strip running back under the hull fixed with screws. I have silicaned this
but with no reduction in bilgewater.

Any other ideas I may have missed?

Cheers

DJ


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.794 / Virus Database: 538 - Release Date: 11/10/2004

xtra wrote:
Hi

I have just got my first fibreglass hulled boat (14 FOOT HALF CAB) and it
appears to have a large leak into the underfloor bilge. After about 4 hours
on the water I have about 4 gallons or more of seawater come out of the
bungs. I have looked under the boat and beyond normal looking scratches in
the gelcoat the only breaches of hull integrity are the front metal centre
strip running back under the hull fixed with screws. I have silicaned this
but with no reduction in bilgewater.

Any other ideas I may have missed?

Cheers

DJ


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.794 / Virus Database: 538 - Release Date: 11/10/2004



It can be deceptive, what looks like a tiny crack or scratch in the gel
coat, can go right through to the glass.

As the boat flexes, they all do, it opens etc letting water in.

Fibreglass itself is surprisingly porous, it's the gel coat one side &
oft the flow coat on the inside that seal it all up. So if water can get
through the gel coat yes it will leak & worse if the hull has suffered
an impact then the underlying glass layup may be damaged (cracked).

Might be best to try & identify exactly where the leak is, assuming you
trailer it, you can leave the water in the underfloor, wipe the hull dry
or just let it dry, then see where any part remains moist at or near a
crack etc, wipe that till dry then check it again if it's moist again
then there is the place.

Careful, the underfloor can hold a huge weight of water, & the boat is
not designed to take load in that direction, nor is the trailer probably
designed to hold it:-) so do it slow & only add a little water if you
don't find any moist parts so think it's getting in further up the hull.
Especially don't go getting under when it's only supported by the
trailer, scary bananas:-)

Once you have ID'd the leak site, you can then empty the water, grind,
clean, dry out & if the glass itself is OK just refinish that area with
a Q cells/resin paste (FGI sell both & give good advice for free:-))
then gel coat or one of the epoxies. If you even remotely suspect the
underlying glass is damaged, repair it because just patching the surface
will only stop the leak for a short time.

Good luck get back & let us know how it goes.

K

The leak might come from the joint between the upper and lower halves ( if
the boat is constructed in that way). Often, when under way, splashed water
will find its way in there and, obviously, drain into the bilge. Is that a
possibility?
--
RichG manager, Carolina Skiff Owners Group on MSN
http://groups.msn.com/CarolinaSkiffOwners

"xtra" wrote in message news:XKWpd.49984

.....After about 4 hours
on the water I have about 4 gallons or more of seawater come out of the
bungs.

A gallon per hour is about the same as a healthy faucet drip. Could be
coming from an apparently small crack.

My boat has a fiberglass hull and I had the same problem...slow leak
that filled the bilge over a period of a few hours. Turned out that
it had dry rot in the transom. The core is made of wood and then
covered with fiberglass.



On Sat, 27 Nov 2004 08:17:59 GMT, "xtra" wrote:

Hi

I have just got my first fibreglass hulled boat (14 FOOT HALF CAB) and it
appears to have a large leak into the underfloor bilge. After about 4 hours
on the water I have about 4 gallons or more of seawater come out of the
bungs. I have looked under the boat and beyond normal looking scratches in
the gelcoat the only breaches of hull integrity are the front metal centre
strip running back under the hull fixed with screws. I have silicaned this
but with no reduction in bilgewater.

Any other ideas I may have missed?

Cheers

DJ


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.794 / Virus Database: 538 - Release Date: 11/10/2004

Sez DJ:...appears to have a large leak into the underfloor bilge. After about
4 hours on the water I have about 4 gallons or more of seawater ...

DJ, lots of information you left out...Are you outboard or inboard (or I/O)
powered? An inboard powered boat will uually have a small steady leak at the
prop shaft packing whereas an I/O or outboard powered boat won't, for obvious
reasons..Though an I/O can leak if the bellows is damaged... Does it leak at
rest (at anchor or in the slip?). Or only underway?..
Have a live bait tank? Sounds to me that you have a real concern, let us know
what you find.
Mike

"xtra" wrote in message
...
Hi

I have just got my first fibreglass hulled boat (14 FOOT HALF CAB) and it
appears to have a large leak into the underfloor bilge.
.....................

Thanks everyone for ideas! I am running an outboard and auxillary outboard
so figure it could only be in the bolt holes from the mounting plates if it
is motor related but these appear to have been well silliconed by the
overfill apparent around the plates. The transom appears sound and passes a
knock and rock check. I am going to give the bilge a fill on the trailer
(supported!) next weekend and check under the hull for wet points. 8P

Will let you know how it goes!

Cheers

DJ


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.794 / Virus Database: 538 - Release Date: 11/10/2004