Skin fittings: when do you replace them?

Skin fittings: when do you replace them?

  • Every 2 years (regardless of conditions)

    Votes: 0 0.0%

  • Total voters
    46
It seems common practice by guardians in the SoF to do as PeteM infers .
Only excerise them on the hard / slings for the reasons stated .
I guess the “ lad “ who,s sent to clean if every two weeks ( firm may have 20 + boats in its stable ) - you know had to rummage around and find them ALL - otherwise with the one he misses it makes the excerise useless .
So you think it’s been done , ie they HAVE done it ,but in the real world one or two are missed .
Leaving s tick box sheet ,just gets lost btw .
When I started boating the guardian Co did or organised everything inc the annual haul out stuff .
For the 1 st 10 years the sea chocks where left open all the time and supposedly excerised as PeteM suggests on the hard .
They used to start and run up systems too before arrival . I know this cos engines were warm and with a mid day summer arrival the air con was running. Unattended!
I thought it was normal
As I moved into semi retirement and full retirement in my early 50.s with time on my hands ( let’s face it you can,t really swim in April and the ski season can extend where we live into April , ) nobody wanted to “boat “ that early .
So with a mate ,I started to do the annual my self .
Two reasons - 1st a heluva lot cheaper DIY and 2nd you know it’s done right .
We even started to to do oil changes on the outdrives etc when I had that boat .
How ever the gurdiane would come to the yard to ckeck up on us “ amateur s”
The 1 st thing he said was
“ have YOU excerised all the seacocks - because NOW is the time to find out if they need changing ?

Then I joined this Forum , Then I changed boats , Then I had them all replaced as the main engines - huge things at €600 each were seized .
My mate —— he’s a serious offshore rag n stick man - think maxi type - W coast of Africa ,Southen Ocean , that type of stuff .
In his world a failed cock / skin fitting could be life or death - he s in the shut em all if the boat is unattended and regular excerise and inspections to prevent failure .
So recently since they are new 2015 I do excerise them every few weeks and close them If unattended- well most

The bilge pump exist is via a manifold under water out of sight .
So that stays open it a big one at the stern

Two of them a bit of a phaff - the galley sink drain is behind a hindged secret flap .
The seawater anchor wash is under a discreet floor pannal also in the master cabin .

That’s point I as the owner know the boat ,but imagine an employee from a guardianarge Co carefully lifting these deliberately concealed access pannals .
Or Yanking off a bad one ! - in good faith .
So that’s why there is a school of thought to leave em all open , and only excerise when “ in the crane “ etc
As said i,ve been in both camps albeit unknowingly.
 
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For the avoidance of doubt, I'm not suggesting that anyone only exercises their seacocks when in the slings or on the hard. I'm just suggesting that when done in the water, it might be worth choosing a time when there is support (e.g. the crane is operating) so that if the worst happened the boat can be lifted quickly.
 
For the avoidance of doubt, I'm not suggesting that anyone only exercises their seacocks when in the slings or on the hard. I'm just suggesting that when done in the water, it might be worth choosing a time when there is support (e.g. the crane is operating) so that if the worst happened the boat can be lifted quickly.

If I can refine that - don,t excerise between the hour s of 12-2 pm in France ,as the yard will be a ghost town - 2 hr Lunch :)
Pay Particular attention to French Bank Hols. - seems like there’s one randomly in every week in the season :)
 
If I can refine that - don,t excerise between the hour s of 12-2 pm in France ,as the yard will be a ghost town - 2 hr Lunch :)
Pay Particular attention to French Bank Hols. - seems like there’s one randomly in every week in the season :)

Indeed, unless you're willing to drive the boat up beach or have a cast iron plan to keep it afloat!
 
Indeed, unless you're willing to drive the boat up beach or have a cast iron plan to keep it afloat!
Not that such plan requires rocket science...
Properly sized wooden cones and a hammer is all it takes - and it's worth having regardless of testing preferences, for rather obvious reasons... :rolleyes:

PS: 'fiuaskme, I'd trust that better than relying on the response of a yard, regardless of how close it is.
 
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Without wishing to spook anyone, is my memory correct and someone once posted a message on here that their sea-cock snapped off when closing it, despite it looking fine from the outside?

Yes, it happened to me. I think there were 2 factors involved though;
1) The original valve was of dubious source from a chandler who was unwilling to take any responsibility or give any real comment as to the source and suitability for the valve he supplied me.
2) The valve was one of the smaller valves you might find (3/4" I think from memory)
3) The valve was a wedge valve (screw stopcock type), not a ball valve (more suitable for boats IMO)

Just to confirm though, it wasn't the inlet or outlet breaking off - in this case the bonnet (top) came away from the body of the valve, with a broken/sheared thread. On inspection I don't think it was corrosion that led to the situation either, more that there appeared to be a fracture in the thread of the valve that gave way under operation. I think the situation would have been mitigated by;

1) Using valves of known quality and suitability
2) Not using a wedge valve, but using a ball valve as they are assembled differently

In my case, replacing that valve for a new valve every 5 years would likely have not changed the situation over time, if I'd used the same source of valve. I could have been replacing a good one for one with a manufacturing defect, or vice versa.

I have now replaced all the valves on board. Some had been there for nearly 40 years. On inspection, the bodies were fine, but where wedge valves had been used, the threads were failing on the valve spindles due to de-zincification. All valves and skin fittings were brass.
 
+1. You beat me to it Mapism. Correctly sized wooden cones taped above each ballvalve on my boat, except for the engine ones, they are so massive it's impossible to imagine them shearing off in my hand! Trouble is, there's only one hammer on the boat and it's in the toolbox hidden away somewhere. With Petem's imaginary 2ft waterspout in the bilges, I wonder how long it would take me to find the hammer? Should I tape a hammer next to each cone? lol.
 
I asked if anyone had experience of ‘plastic’ skin fittings/seacocks on Pete’s thread but no one answered, maybe because not many have any real experience of them?

Did a quick bit of Google research to see if I could answer my own question and found this http://www.forespar.com/what-is-marelon.shtml

Seems they are polymer and the claim is that they are every bit as good as bronze. Worth watching the vid.
 
I asked if anyone had experience of ‘plastic’ skin fittings/seacocks on Pete’s thread but no one answered, maybe because not many have any real experience of them?

Did a quick bit of Google research to see if I could answer my own question and found this http://www.forespar.com/what-is-marelon.shtml

Seems they are polymer and the claim is that they are every bit as good as bronze. Worth watching the vid.
I must have missed the thread. I am in the process of changing all mine to Forespar Marelon. I started with the engine inlets two seasons ago, just after I bought the boat, and so far so good.
 
Understandable choice, which I'll definitely consider if and when I should replace something.
Actually I didn't for the valve that I mentioned in my post #12, but for such small thing, a like for like replacement was the more obvious choice.

The only point I've yet to understand about polymer stuff is how stable they are over time.
I mean, I understand that their resistance to corrosion is superior to any metal of course, but as with any synthetic products, they could also suffer other types of age-driven deterioration.
Good quality bronze skin fittings properly installed are known to last for a quarter of a century, as BartW testified.
What happens to Marelon components over such timeframe is yet to be discovered, I suppose...
 
This has been discussed on the rag n stick forum.

http://www.seabung.com/video.html

Has anyone got or tried one of these things?
Now, that looks VERY clever indeed, thanks P for highlighting it!
I would also be curious to hear if they work as they should - and as reliably as required by such critical application.
What did raggies tell about it? With apologies for my laziness in searching the other forum... :o
 
Understandable choice, which I'll definitely consider if and when I should replace something.
Actually I didn't for the valve that I mentioned in my post #12, but for such small thing, a like for like replacement was the more obvious choice.

The only point I've yet to understand about polymer stuff is how stable they are over time.
I mean, I understand that their resistance to corrosion is superior to any metal of course, but as with any synthetic products, they could also suffer other types of age-driven deterioration.
Good quality bronze skin fittings properly installed are known to last for a quarter of a century, as BartW testified.
What happens to Marelon components over such timeframe is yet to be discovered, I suppose...

I was wondering the same thing. Couldn’t find anything about longevity.......
 
The Forespar Marelon are made from a composite material, much as the rest of our GRP boats, so my view was that they would likely last as long as the rest of the plastic composite in which they are fitted. I have read up on a couple of horror stories, but then this is definitely the case with brass, and even bronze seacocks may be mixed with other materials for the skin fittings. The Marelon is a complete item.

They also include a simple plastic plug to allow them to be dismantled in the water, although you do have to swim down to pop the plug in from the outside.

I have installed the first ones on mine with a marine ply backing pad ~ 3 x the hole diameter on the inside of the hole, and used 291 to seal everything.

This haul out I will be changing those serving the heads and this also rids the boat of some more bonding cables.
 
Now, that looks VERY clever indeed, thanks P for highlighting it!
I would also be curious to hear if they work as they should - and as reliably as required by such critical application.
What did raggies tell about it? With apologies for my laziness in searching the other forum... :o

There was little experience of actually using them, which I suppose is a good idea. They do however look like a useful bit of kit to carry. Buy the pack of two and you have something that would fit most thru-hulls (not sure about the cooling water intake for a big diesel though). Personally, I wouldn't want to use them at planning speeds - too much risk of dislodging it.

Much cheaper than a lift and hold in the slings if you needed to change a sea cock in an emergency. Doesn't help with replacing the thru-hull itself if that is the problem.
 
(not sure about the cooling water intake for a big diesel though).
That's exactly my doubt. According to their website, "Each pack of Seabung is supplied in diameters of 60 and 90mm for use on holes 19 to 52mm".
And while 52mm would have been enough for the engines intake of the old lady, it ain't sufficient in the DP.
Actually, the whole assembly (thru-hull+valve) in the DP is so massive that it's hard to imagine it snapping off, but it's also true that such event would be the most critical to deal with - also with wooden cones or anything else, btw...
Oh, well. I made a mental note about that in the (pretty long!) list of nice to have bits of kit.
Let's see, maybe they will come out also with a third, larger size... :encouragement:
 
I have original 39 yr old bronze, in as new condition. & inspected annually.
Could`nt vote as no option offered
 
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