Seacocks servicing

[oldbilbo]

I'm pondering what needs to be done to inspect and ensure serviceable all my seacocks and other through-hull apertures, which haven't been disturbed for some years AFAIK.

There are 7 bronze through-hulls, with no sign of corrosion. Additionally, there are 2 holes for anode bolts, 1 for the engine exhaust, 1 for the speed transducer, and two others apparently for depth.

Would it be appropriate to remove each seacock? What should an inspection reveal? What, if anything, should be used to lubricate the action? How should the threads be sealed on re-fitting?

Any tricks for releasing/removing the reinforced hoses, after the circlips have been released?

The engine cooling water inlet on one side is matched by a similar though-hull and stopcock on the other side, which is not connected to any pipe. Would it be useful to join both inlets, the better to supply raw cooling water in event of a potential blockage of one?

 

[rickym]

All I have ever done over the last 20 odd years is inspect the hoses and disassemble and grease the blakes seacocks. Have replaced the odd perished or weeping hose, never taken the seacock out of the hull.

 

[Searush]

Sounds like Russian Roulette to me! If they aren't leaking & they turn on & off, is disturbing perfectly waterproof below waterline joints a good idea?


If it ain't broken, don't try "fixing" it, cos it will sure as hell end up broken if you do!

I free my Blakes cocks if they seize, but otherwise, just making sure they work is fine. I have NEVER disturbed the cock/hull joint & wouldn't unless the cock HAD to be replaced due to severe corrosion & inability to seal.


Don't you have enough jobs to do already? Do you really need to make more work for yourself?

 

[john_morris_uk]

All I have ever done over the last 20 odd years is inspect the hoses and disassemble and grease the blakes seacocks. Have replaced the odd perished or weeping hose, never taken the seacock out of the hull.

I agree - give them some gentle taps with a hammer to check that they are still firm and have a nice sound when struck. Scrape the antifouling off and check that they are still bright and shiny metal underneath. If they are not leaking, why go looking for problems.

With Blakes seacocks its worth checking the fastenings - I have had to replace those a couple of times in the past as they were crumbling to bits when I examined them closely.

 

[oldbilbo]

I sense that some are confusing 'through hull fittings' with 'seacocks'. These latter are, in my li'l boat, screw-mounted onto the bronze 'through hull fittings'.

I have no concerns about the bronze fittings. Each and every one is 'sound as a pound'. However, the various BRASS seacocks screwed onto them need a closer look IMHO.

As one of the more important of my principles is 'to keep the ocean on the outside', it seems to me that a close inspection of the current state of those BRASS components is warranted - and photographed 'for the record'.

 

[prv]

In that case, are they ball valves or gate valves?

The former are generally regarded as maintenance-free apart from occasional movement to stop them freezing up. The latter are generally regarded as unsuitable except on the domestic central-heating systems they were designed for.

Pete

 

[Tranona]

I sense that some are confusing 'through hull fittings' with 'seacocks'. These latter are, in my li'l boat, screw-mounted onto the bronze 'through hull fittings'.

I have no concerns about the bronze fittings. Each and every one is 'sound as a pound'. However, the various BRASS seacocks screwed onto them need a closer look IMHO.

As one of the more important of my principles is 'to keep the ocean on the outside', it seems to me that a close inspection of the current state of those BRASS components is warranted - and photographed 'for the record'.

If they really are "brass" then they would probably have corroded away long ago!. If they are DZR (which is the most likely) then they should last as long as "bronze". If you are really worried then unscrew them from the skin fittings, clean them up, check that the balls run smoothly and refit them. You can of course do most of this without removing them - clean them and tap them to determine they are still sound and operate them several times. You may find it useful to clear any debris from the outside first.

 

[john_morris_uk]

No confusion - except in what we classify as what. I tend to think of the whole assembly - "hull fitting/valve/hose tail" as the 'seacock' - hence my comments about checking them in the way I said etc. If you really have brass valves I would be concerned. Are you sure they are brass?

 

[Piers]

Hi,

I was told last year by someone in the Channel Islands of a yacht which had sunk because a sea-cock had failed. The insurance company only paid a small percentage of the value stating the sea-cocks hadn't been serviced in accordance with the manufacturers' instructions. (can you remember the PBO (?) report on incorrectly manufactured sea-cocks?).

Apparently, there's a specific seacock which looks like bronze and which is engraved 617N. To meet RCD, seacocks only have to have a 5 year life. These 617N sea cocks are apparently vulnerable.

Hence, 'if not serviced' in accordance with etc, cover is invalid.

"Bandit" of this parish knows much more about this. He tapped one with a hammer and it fell off....thankfully, the boat was ashore at the time.

 

[vyv_cox]

Apparently, there's a specific seacock which looks like bronze and which is engraved 617N. To meet RCD, seacocks only have to have a 5 year life. These 617N sea cocks are apparently vulnerable.

CW 617N is leaded brass. Most chandlers sell it as Tonval. It has very poor corrosion properties in seawater but is fitted as original equipment by HR, Maxi, X-yacht, Dehler, Malo and others.

 

[prv]

It has very poor corrosion properties in seawater but is fitted as original equipment by HR, Maxi, X-yacht, Dehler, Malo and others.

Bonkers!

Pete

 

[vyv_cox]

Bonkers!

Pete

This is HR's response to a query as to why they used this brass

'As with everything on a boat, seaworthiness is not something that is achieved once for ever but something that is subject to continuous controls and updates by the responsible captain. I think it is a good routine to check also through hull fittings when the boat is ashore. You do so by using a hammer and a screwdriver and hit the fittings from the outside. If they seem porous, it is time to think of replacement. If they are not porous, I see no reason to do anything.

It is always up to each boatowner to what extent he wants to go in upgrading his boat. If it was my boat I would call it a waste of time and money to change to bronze fittings.'

 

[oldbilbo]

Well, that's HR off my list....

 

[Searush]

This is HR's response to a query as to why they used this brass

'As with everything on a boat, seaworthiness is not something that is achieved once for ever but something that is subject to continuous controls and updates by the responsible captain. I think it is a good routine to check also through hull fittings when the boat is ashore. You do so by using a hammer and a screwdriver and hit the fittings from the outside. If they seem porous, it is time to think of replacement. If they are not porous, I see no reason to do anything.

It is always up to each boatowner to what extent he wants to go in upgrading his boat. If it was my boat I would call it a waste of time and money to change to bronze fittings.'

Utterly bonkers - to risk lives for the sake of a couple of hundred quid on 100K boat!

 

[Ripster]

CW 617N is leaded brass. Most chandlers sell it as Tonval. It has very poor corrosion properties in seawater but is fitted as original equipment by HR, Maxi, X-yacht, Dehler, Malo and others.

I had a well known Hamble dealer/agent change over two stiff ball valves and with it he did the skin fittings and tails - so all the kit was new on these two BWL fittings. This was about three years ago when I bought our current boat. At the time, it did not occur to me that he would use anything but recommended kit. When this whole subject came up 6-9 months ago I checked mine and he had used C617n fittings and valves - clearly marked So, also being unable to identify what all the others were made of (the rest of the originals), I have had them all done now with bronze fittings that I sourced and checked out! The point being that agents/dealers are (or some clearly are) fitting the non-recommended materials for Sea use. Having now looked at the old fittings on the bench, in fact they were still serviceable, but you can on at least 4 of the components see the pinking/redening process at work. Two of the bigger valves (1 1/2") had to be cut off - they would not budge even with a 3 foot bar on.

 

[jfkal]

How about that

It is probably best to change them every 5 years or so. It is hard to see which ones are really suitable and silent internal corrosion can lead to sudden failure. Read the fine print: Many which you can find and called Seacocks state somewhere (not suitable for salt water or not suitable for below water line installation!!! HAHA, what else would you use them for then ????) And all of those are used EXACTLY for that (saltwater and below water line).
My experience:
1 All looked fine when I got the boat. Just on a hunch changed them all (most were corroded internally leaving only a paper-thin wall)
2 Changed to one of the top brands only to find the stems braking off (crevice corrosion).
Manufacturer recalled the whole batch as they had used bad quality SS instead of bronze.
Go figure. Treat them as a consumable and not a fixed asset.
It is cheap to change them during a scheduled haulout but expensive to recover them from the sea floor ;-).

I'm pondering what needs to be done to inspect and ensure serviceable all my seacocks and other through-hull apertures, which haven't been disturbed for some years AFAIK.

There are 7 bronze through-hulls, with no sign of corrosion. Additionally, there are 2 holes for anode bolts, 1 for the engine exhaust, 1 for the speed transducer, and two others apparently for depth.

Would it be appropriate to remove each seacock? What should an inspection reveal? What, if anything, should be used to lubricate the action? How should the threads be sealed on re-fitting?

Any tricks for releasing/removing the reinforced hoses, after the circlips have been released?

The engine cooling water inlet on one side is matched by a similar though-hull and stopcock on the other side, which is not connected to any pipe. Would it be useful to join both inlets, the better to supply raw cooling water in event of a potential blockage of one?

 

[FlyingDutchman]

Is the material of the seacocks also an issue / risk when the boat is used on fresh (inland) water only?

 

[vyv_cox]

Is the material of the seacocks also an issue / risk when the boat is used on fresh (inland) water only?

Not a big risk I suspect and it depends where the boat is based. DZR was developed for the plumbing industry when brass valve failures occurred in soft waters. I can vouch for this,having had stopcock corrosion at home, where our water is extremely soft.

 

[angelsson]

Utterly bonkers - to risk lives for the sake of a couple of hundred quid on 100K boat!

Must say +1 to that, common sense.

 

[FlyingDutchman]

Thanks Vyf.
The seacocks on my boat look like brass with a dull chromium plating on the outside. Do you think that would be ok for inland waters? After 17 years they look good from the outside, but I am a bit reluctant to tap them with a hammer as this might damage tha sealing to the hull?