Hull skin fittings - glassing in only OK?

LittleSister

LittleSister

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Our recently acquired 'project boat' has several of the underwater hull skin fittings glassed in inside the hull, but not clamped or bolted through from the outside of the hull.

I assume this is not considered acceptable practice, but before I tackle the grim and expensive job of grinding them out and replacing them, can anyone confirm my understanding is correct?
 
Elanco hull seals marketed by Lamdermores
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Quite common at one time to glass them in. If they are bronze (most likely) or DZR then no reason to replace them unless they are worn to the point they don't seal or operate correctly.
 
Tranona said:
Quite common at one time to glass them in. If they are bronze (most likely) or DZR then no reason to replace them unless they are worn to the point they don't seal or operate correctly.
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One at least is a Blakes. Nothing wrong with the operation of them (no leaks, and good integral seacock on the Blakes), but they're fixed only to the inside of the hull.

I just need to know if that's considered safe, and acceptable to insureres/surveyors.
 
Presumably there is in each case a flange on the outside. To accidentally detach the GRP inside would neeed a hammer and chisel, so is it likely you or something accidental could push the fitting out of the hull? There have been instances of threaded seacocks giving up (electrolysis presumably) and the seacock falling off inside, that won't happen to you, and even if the outer flange dropped off you would remain safe until you applied enough force to crack it off inside. Many rudder posts and stern tubes are only glassed in.
If it looks sound leave it?
 
West System (the epoxy people) bang on a lot about structural bonding with Epoxy including the bonding of various metals to GRP. Based on their experiences and practices its obvious that high strength and integrity can be obtained through bonding. While your GRP glue is not likely to be Epoxy, the same principles apply. The skin fittings will not be sitting within the GRP simply being held in place, they will be physically bonded to the GRP by the glue.
 
LittleSister said:
One at least is a Blakes. Nothing wrong with the operation of them (no leaks, and good integral seacock on the Blakes), but they're fixed only to the inside of the hull.

I just need to know if that's considered safe, and acceptable to insureres/surveyors.
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I think you will find they have a flange on the outside which sits in a recess in th hull moulding. There could well be a nut that has been glassed over.
They have probably been assembled to the hull with a layer of mastic to seal the fitting to the hull.
I don't think there is any problem.
My only concern would be fittings glassed in with no mastic, sealant or gasket, might eventually weep as polyester is not a brilliant glue for metals.
Less likely to fail in a big way than a soggy bit of plywood IMHO.
 
LittleSister said:
One at least is a Blakes. Nothing wrong with the operation of them (no leaks, and good integral seacock on the Blakes), but they're fixed only to the inside of the hull.

I just need to know if that's considered safe, and acceptable to insureres/surveyors.
Click to expand...

Glassing in Blakes fittings was common in the 70's and 80's by such builders as Contessa and Sadler and no doubt others. In those days the bodies were bronze and there is no reason why they should not last the life of the boat, provided the cones are kept lubricated and the bores don't go oval. Worth having the cones out and maybe lapping them in with grinding paste, cleaning, then re-assembling with Blakes grease.
 
Chrissie said:
Pictures of inside and out would be good
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i cant find the "elanco" site since Landamores were taken over by Oyster.
my elanco have a flange & spigot. the spigot passes through the hull & cut off flush, the flange is glassed over.
the skin fitting shaft has a cap that screws down to make the hole flush on the outside

Ah found it
http://landamores.co.uk/yachts/elanco/
 
fisherman said:
Presumably there is in each case a flange on the outside..... Many rudder posts and stern tubes are only glassed in.
If it looks sound leave it?
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There is no flange on the outside of the hull. There is simply a hole in the hull, and inside a skin fitting/seacock bonded to the inside of the hull with grp.

I will try to take some pics - will post them in a few minutes.
 
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LittleSister said:
There is no flange on the outside of the hull. There is simply a hole in the hull, and inside a skin fitting/seacock bonded to the inside of the hull with grp.

I will try to take some pics, but I think the camera isn't here at the moment and it's a bit too dark just now for the camera on my phone, so it's likely to be tomorrow.
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So there is just a flange between two layers of GRP?
I can see that being just as strong as the hull, the only issue might possibly be the bond between the hull and the fitting. If water can get in there, corrosion and small leaks might occur. I would think if it's lasted a few years it will last many more, there is no great load on it, and quite a lot of area being bonded. It may be that the flange is sikaflexed to the inside of the hull then glassed over? That sounds fine to me....

On my Oyster, there were flanges on the outside, but they sat in moulded recesses in the hull, and were then faired with filler. So the outside was totally flush.
 
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lw395 said:
So there is just a flange between two layers of GRP?
I can see that being just as strong as the hull, the only issue might possibly be the bond between the hull and the fitting. If water can get in there, corrosion and small leaks might occur. I would think if it's lasted a few years it will last many more, there is no great load on it, and quite a lot of area being bonded. It may be that the flange is sikaflexed to the inside of the hull then glassed over? That sounds fine to me....

On my Oyster, there were flanges on the outside, but they sat in moulded recesses in the hull, and were then faired with filler. So the outside was totally flush.
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your Lightwave is an EGB cored hull so a different system to fix the skin fittings ;)
 
sailorman said:
your Lightwave is an EGB cored hull so a different system to fix the skin fittings ;)
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Actually solid around the skin fittings, at least the ones the designer remembered...
But they were just backing nuts on the inside.
And some incredible jointing compound.
I replaced them all. You could remove the backing nut, hammer the fitting out from the inside, then by the time I'd got out of the boat and down the ladder, the jointing compound had pulled the fitting back into place.
 
LittleSister said:
There is no flange on the outside of the hull. There is simply a hole in the hull, and inside a skin fitting/seacock bonded to the inside of the hull with grp.

I will try to take some pics - will post them in a few minutes.
Click to expand...

They will be standard Blakes fittings with a flange that is glassed on the inside and a spigot going through the hull, cut off flush, so all you will see is the hole. When it is used as a bolt through fitting there is an outer flange with square holes for the heads of the 3 coach bolts.

Not entirely sure why you are worried about this. The bronze is just about indestructible and if there is no sign of delamination of the hull, the only thing you have to worry about is any wear in the tapered cone or its housing. As I suggested above this can be dealt with by lapping in the cone. You may also want to look at the screws and nuts holding the keeper plate as some people don't realise these are threaded in the body and they can easily be damaged by overtightening.
 
Tranona said:
They will be standard Blakes fittings with a flange that is glassed on the inside and a spigot going through the hull, cut off flush, so all you will see is the hole....

Not entirely sure why you are worried about this....
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Thanks, Tranona (and others). Very reassuring, and has saved me some time, sweat and money.

I was only worried about this as I'd previously only ever seen bolted/clamped through skin fittings, and assumed this might be some bodge which might be either (a) not safe, or (b) not acceptable to the surveyor when I come to get an insurance survey done before launching. The seacocks appear to have been in there for many years, and quite possibly since the boat was built in 1976 (somewhere very close to Landamores!).
 
The Jeremy Rogers Blake's efforts, already mentioned, used four fixing bolts contersunk on the outside of the hull and filled. I guess this was to assist the sporting performance of the boats and to save a few bob.
You may find you have similar with the nuts hidden under the inside glasswork. In fact can I see one, just peeping out in the last two pictures?
 
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