Skin fitting rotated a bit.

CaptainBob

CaptainBob

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I've removed an un-used seacock with the intention of putting a blanking cap directly onto the threaded tube that comes in through my hull.

During the seacock removal, the skin fitting (brass by the way) rotate a little bit.

The sealent which previously was "glued" to the inner and outer surfaces of the hull, is now not "glued" (if you know what I mean?).

Now, on the inside of the hull is a thin nut which holds the skin fitting tight into the hull.

2 questions...

1. Do you think I need to completely remove and re-seat the skin fitting, with new sicoflex (spell?) or similar?

2. When I tighten the nut that holds the fitting in place, how do I stop the skin fitting from simply rotating in place instead of being pulled up tighter into the hull?

Does that make sense?

Thanks!
 
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1. Do you think I need to completely remove and re-seat the skin fitting, with new sicoflex (spell?) or similar?

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Yes!

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2. When I tighten the nut that holds the fitting in place, how do I stop the skin fitting from simply rotating in place instead of being pulled up tighter into the hull?

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There should be two small lugs inside the barrel of the skin fitting which an assistant can use to hold it in place from outside the hull using long nose pliers (or similar tool) whilst the person inside does the business with a spanner.
 
You said the skin fitting was brass. Now would be a good time to fit bronze instead or at least DZR brass to avoid corrosion problems in future. Problem is that many brass fittings are labelled as bronze. Some other forum member will be able to specify correctly the bronze type required. The main thing is to by an alloy of copper and tin, not copper and zinc.
 
Tip. When re-fitting put sikaflex on outside and just nip up the nut inside with a couple of spacers under each side. When Sikaflex is cured, remove spacers, unscrew nut, put more Sikaflex under nut and tighten. This will give you a good seal and fitting won't turn when doing up nut. /forums/images/graemlins/wink.gif
 
Don't even think about it, remove the old one,clean both inside and outside and re-fit properly and re-seal, maybe with a new one as suggested.
Tighten internaly as said above with a mate outside jamming the two internal lugs of the skin fitting with a spanner.
If you don't it will leak!
 
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Oh, maybe it is bronze. It's completely free from corrosion.

[/ QUOTE ] Not so much corrosion that you should worry about as dezincification. Brass dezincifies. That is the zinc is dissolved away. It can be spotted usually by a pink appearance of the surface. A dezincified fitting will have virtually no strength.
 
Alternatively, as you apparently have no intention of using the fitting, why not remove it, and patch the hole with glass cloth and epoxy?
Just a thought, then you dont have to worry about possibly buying new fittings to do nothing.
 
Bajansallor is very wise. If you can do without the fitting and seacock just fill the hole then forget all about it. Here assuming the boat is out of the water....
You shamfer a gradient on both the outside and inside of the hull. From about 1 cms wider radius at the skin to about 1/4 depth from outside and another 1/4 depth from inside.
Now get your f/g cloth and cut many layers. This depends on the weight of cloth but you need to replace the full thickness of f/g of the hull ie .5cm thick so expect 10 or so layers of glass.
2 circles of f/glass will be the size of the largest area of shamfer. ie for a 50mm hole 70mm in dia. Each pair of circles of f/g will diminish in size until you have 4 circles exactly the size of the hole 50mm.
Divide the circles of f/glass into 2 sets.
Start from the inside. Get a supermarket plastic carry bag or similar with a kg of sand in it. (sealed) You need to be able to hold this bag up against the skin with prop or similar. Hopefully the bag will sit protruding into the hole to about halfway through the hull.

You can now lay up f/g with resin onto the plastic bag putting each f/g layer in with resin smaller first. if you have enough f/g the surface should be level with the inside of the hull. Stick another couple of layers even large over the patch on the inside if you feel like it.

When it is hard remove the plastic bag. Being plastic it should not stick to the hardened resin. Now lay up f/glass circles from the outside against the inside patch smallest first until hopefully the outer hull surface is level. Let it harden sand clean level and rough for paint attachment. You will soon forget it was ever a hole.

You can use polyester resin or epoxy. You will need to warm the enclosure for epoxy. The secret of this patch is that the inside patch and outside patch chemically bond providing the first patch has not good off completely. ie put the second patch on when the first is hard enough to support itself but don't leave it for weeks between patches. Work the resin in to exclude all air bubbles.

By its shape the patch will be locked in so polyester is OK even though normally its adhesive ability is not as good as epoxy. Polyester can be induced to harden quickly and at lower temps with more hardener but beware the resin going off in the pot. It would be worth doing a practice glass lay up first to get the hang of it.
It is a whole lot more permanent than refitting brass fittings. olewilll
 
Similar thing happened to me at the start of the season, when I renewed the raw water intake pipe. The fitting wept a bit (weeped?) but soon stopped and was never worse than the stern gland. But I worried about it all summer, and if I'd been able to get her out of the water for a weekend I'd have been happier reseating it with sikaflex. It is at the top of this winter's job list, if you don't do it you'll have that recurring dream about the tip of the mast sticking out of the water next to the mooring buoy.
 
I had exactly this issue on a previous boat where I had a redundant sea-cock.
I removed the whole fitting and plugged the opening with a f/g and resin and epoxy plug.
It's very easy - but if doing it in winter you will need some kind of heat to get the resin to harden.
 
Fill and reglass the hole if you can.

I had a through hull go 200nm offshore and you don't want that at even 30mtrs offshore

I nearly lost the boat
 
I appreciate the thought that re-glassing it is the best way forward - but it's bloomin chilly here now, and will be right up to the point that I go back in the water.... also I've never done ANY glassing, I have no power available at the boat, and a blanking cap is gonna cost me £3.48GBP... so I think it's gonna be a sikaflex and blanking plate job for the moment.

Many thanks for the detailed glassing post olewill!! I'll print that and keep it for next lift out.
 
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