Leaking Hull GRP - Options?

[barrow_matt]

I have found my boat is taking on water through the hull where the centre bilge keel is attached. There are no obvious holes or cracks but it just slowly comes through, you can't see it but after 5-10 minutes you can see a difference.

The boat has been on a very exposed mooring and only just moved to a sheltered mooring that is dry for longer this week. I'm going to keep an eye on it every couple of days.

What are the options to repairs this? It is a single centre bilge keel and GRP hull. The boat is not worth a great deal so needs to be a budget repair or probably not worth it. I will be taking the boat out of the water fairly soon to rectify this.

 

[tyce]

Just out of interest is it the blue hulled yacht thats been moored of roa island.

 

[oldsaltoz]

My advice would be to confirm the point of entry before lifting out as this may save a lot of time and expence, knowing the point of entry will indicate what needs doing.

Wipe the area dry and sprinkle some talcum powder all around the area, it will leave a clean area around the point of entry thus ensuring your diagnosis is correct.

Dropping the keel and repairing perhaps a crack will not cost the earth, indeed the leak might just be a leak around a keel bolt, the powder will show this.

Good luck and fair winds.

 

[Seajet]

The advice by Oldsaltoz is spot on; and bear in mind that once the boat is ashore and resting on her centre keel, any gap may / will close up making diagnosis a lot harder.

In a pefect world maybe you could approach it the other way round, suspend the boat on trestles / crane ( time taken would be too long usually ) and pour water - coloured with food dye to be more visible - and look for the leak on the outside.

It will probably be a case of dropping the centre keel off and checking / changing bolts, glassing over any crack then reseating the keel on mastic; so if you can do anything to prepare for that ?

Trestles or a pit under her shore spot ?

And will she be stable & the hull properly supported if the centre keel is removed without using trestles ?

Trestles don't need to be elaborate, and one similar way would be stands either side supporting a webbing sling, one forward one aft.

 

[Lakesailor]

Little confused.
You mean it is a fin keel boat with just one keel on the centre line?
Bilge keels tend to be in pairs.

 

[macd]

The crucial issue is whether the affected GRP laminate has become porous and been weakened as a result. I'n the first instance I'd suggest you follow the advice above: if you'e lucky, the water ingress could simple be via the keel fastenings.

If not, and the GRP has seriously weakened, it may even have reached the point where it can be deformed simply by pressing on it. This obviously betrays a serious structural weakness. If so, you may wish to have someone knowledgeable about GRP to take a look at it.

Even in that case the laminate may be repairable. Since you say it's an old boat, you're perhaps not too fussy about apperance (and the repairs will be out of sight anyway). You'll need to grind away any delaminated areas, then allow what's left to dry very, very thoroughly. Paradoxically this will require periodic washings with lots of fresh water since the products of osmosis (if that's what it is) are hygroscopic so you need to flush them out of the GRP. When that's done you'll need heavy lay-ups of cloth and epoxy inside and out, probably with added internal stringers bonded-in. It won't look pretty but it should be sound. But again, take advice from someone knowledgeable: it's a pretty vital area of your boat.

 

[barrow_matt]

Just out of interest is it the blue hulled yacht thats been moored of roa island.

Yes, that's the one.

The boat is a Fantasie 19 so has a centre weighted bilge keel and plates either side. The plates would support the hull to remove the keel.

Would the bolts typically go from the floor down into the keel? If that is the case then the heads have been glassed over, would these need to be carefully cut around to ensure not to go any deeper than the layer covering them.

I am a member of a club so I have a berth out of the water and i'm sure there will be a few knowledgeable guys there who would offer some assistance.

 

[reginaldon]

My wee bilge keeler had a mysterious leak - checked (apparently) every possibility - about a bucketful ev. two tides at my half tide mooring - ultimately found a patch the size of a 10p, bare of gelcoat under encapsulated keel - epoxy putty - job jobbed.

 

[Lakesailor]

I would be wary of relying on the bilge plates alone to support the weight of the boat.
There is an owner on here called (funnily enough) Fantasie19

The bilge plates are called that because they are attached to the bilges (more applicable I suppose to a round-bilged boat that a chine hull) and the keel in the centre is just a stub keel.

The bilge plates are supposed, amongst other things, to be a help in keeping the boat upright when it dries out, although it doesn't always work out that way

 

[reginaldon]

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I would be wary of relying on the bilge plates alone to support the weight of the boat.
There is an owner on here called (funnily enough) Fantasie19
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Every boat in our club/harbour does!

 

[Lakesailor]

Are they designed as bilge keelers without a centre stub keel? A chine hull with the plates in the centre of a flat panel is not going to be very stable without a stub keel if they are not designed to carry that weight.

 

[tyce]

Yes, that's the one.

The boat is a Fantasie 19 so has a centre weighted bilge keel and plates either side. The plates would support the hull to remove the keel.

Would the bolts typically go from the floor down into the keel? If that is the case then the heads have been glassed over, would these need to be carefully cut around to ensure not to go any deeper than the layer covering them.

I am a member of a club so I have a berth out of the water and i'm sure there will be a few knowledgeable guys there who would offer some assistance.

I was watching that boat throughout the recent gales we have had, if from the hammering i observed the most damage is a leaky keel then i would be mightily impressed with it.
That is one exposed mooring you have, i have never seen a boat take such a battering

 

[barrow_matt]

I was watching that boat throughout the recent gales we have had, if from the hammering i observed the most damage is a leaky keel then i would be mightily impressed with it.
That is one exposed mooring you have, i have never seen a boat take such a battering

It certainly did from the few times i'd seen it, lost the front hatch and thought initially that the water may have come from waves going over the front but no it is a leaky keel area. I've been quite ill at the late part of the last year so had very little use of the boat and missed the normal window to get it back on land. In a similar vein to another thread on here there was a period when I thought if it had just broken loose and sunk it would be lot less stressful for me with everything else going on but now i'm glad I have recovered it in one piece.

I moved it on Monday, had to walk out at low tide (5.30am) in the dark and sit it out until high tide to move it round the side. It was touch and go for a bit when I released the mooring line as the wind and waves (3-4ft) were turning me in the wrong direction. My 4hp outboard running flat out just managed to regain control and I slowly made my way up past the lifeboat station, I did cut inside one of the buoys either side of their slipway which is probably not allowed but I just had to make it round the corner!

It's like a summer afternoon around the side, flat calm water and I finished the day with a good swim back to shore rather than wait another few hours.

It was sitting ok in the water today, will go back tomorrow morning after low tide and take a closer look underneath.

 

[Seajet]

Are they designed as bilge keelers without a centre stub keel? A chine hull with the plates in the centre of a flat panel is not going to be very stable without a stub keel if they are not designed to carry that weight.

Lakesailor,

it's a centre ballast keel - reasonably long - with flat bilge plates, as your photo spectacularly shows.

Fantasie 19 does well with his, though years ago I knew someone ( who we always suspected dabbled with funny substances ) who swore his would rise up and plane on the tips of the keels...

barrow matt,

if the boat has had the pounding described, it's probably a good thing the apparent problem is from the much stronger central keel; but check the hull around the bilge plates for any deformation.

Good luck !

 

[Lakesailor]

Lakesailor,

it's a centre ballast keel - reasonably long - with flat bilge plates, as your photo spectacularly shows.
!

I think you have become a bit disoriented

I have already described the keel arrangement in another post.
The question I posed which you have quoted was aimed at reginaldon who told me all the boats in his harbour dry out. I was trying to determine if they were built as bilge keelers and thus would be robust enough to dry out.
The Fantasie seems to rely on it's stub keel to sit on.

 

[barrow_matt]

I think you have become a bit disoriented

I have already described the keel arrangement in another post.
The question I posed which you have quoted was aimed at reginaldon who told me all the boats in his harbour dry out. I was trying to determine if they were built as bilge keelers and thus would be robust enough to dry out.
The Fantasie seems to rely on it's stub keel to sit on.

Yes it is certainly robust enough, and indeed designed to sit on it's stub keel.

Since my initial post Steve (Fantasie 19) was kind enough to post on the owners group on my behalf and i've had a response from another owner currently in the process of removing and refurbing the keel. The opinion of everyone so far is that the bilge plates should not be trusted to support the full weight of the hull therefore it should be propped/framed for the keel removal.

 

[Lakesailor]

The opinion of everyone so far is that the bilge plates should not be trusted to support the full weight of the hull therefore it should be propped/framed for the keel removal.

Aaah. That was my point.
I know the stub keel is designed for supporting the weight of the boat. It was your suggestion of

The plates would support the hull to remove the keel.

that I was concerned about.

 

[LeonF]

MY first boat was a Fantasie 19, fantastic little boat, if only the berths were slightly bigger! My bilge plates had additional plates welded to the lower ends, perhaps for a bit more ballast.

 

[reginaldon]

I think you have become a bit disoriented

I have already described the keel arrangement in another post.
The question I posed which you have quoted was aimed at reginaldon who told me all the boats in his harbour dry out. I was trying to determine if they were built as bilge keelers and thus would be robust enough to dry out.
The Fantasie seems to rely on it's stub keel to sit on.

Belatedly - yep all designed bilge keelers.