Under sink seacock knackered?

S

steve yates

Well-Known Member
Joined
16 Oct 2014
Messages
4,117
Location
Benfleet, Essex/Keswick, Cumbria
Visit site
Starting to explore the plumbing as one of the next possible stages in the refit of my lonbow.
I‘m guessing the one on the left needs replacing?
5F8DA4C8-ABF5-4C0F-B6DB-6CB5909C5502.jpeg
I have some old Blakes I refurbed, or I could get trudesign, bit am I right in thinking I probably wont get a straightforward swap out And might need to redo the hole and the throhull itself?
What would you reccomend here!
ps, not sure why there are two as there is one tap, one from the coolbox drain hole perhaps?
The tap has never really been used by me since I got the boat.
Thanks.
 
Is the boat in the water? I would follow the second hose, you need to know what is attached to it. Might be left over from something else long ago.
 
steve yates said:
Wasnt sure if i need new thro hulls to match different types of seacocks or if they are standard fittings.
And no, the boat is out of the water.
Click to expand...
Both need replacing as gate valves should not be used, standard thread size, if cost an issue easy to fit stainless ball valves, go to to a plumbers merchant for better cost
 
steve yates said:
Wasnt sure if i need new thro hulls to match different types of seacocks or if they are standard fittings.
And no, the boat is out of the water.
Click to expand...
They are original Westerly fit and the through hulls will almost certainly be bronze so could be retained. The gate valves will also probably have bronze bodies but the interior mechanism will be rubbish and probably seized. Replace the gate valves and hose tails with DZR ball valves.

While Blakes are good you will need new holes for both the body and the 3 fixing bolts and not really necessary, plus the one on the left is 1/2" and Blakes are only 3/4" or 1 1/2". Blakes were made specifically for their toilets and straight through ball valves are better for drains like these.
 
Tranona said:
They are original Westerly fit and the through hulls will almost certainly be bronze so could be retained. The gate valves will also probably have bronze bodies but the interior mechanism will be rubbish and probably seized. Replace the gate valves and hose tails with DZR ball valves.

While Blakes are good you will need new holes for both the body and the 3 fixing bolts and not really necessary, plus the one on the left is 1/2" and Blakes are only 3/4" or 1 1/2". Blakes were made specifically for their toilets and straight through ball valves are better for drains like these.
Click to expand...
Ah ok, if they wont fit the throhulls then it wont be blakes.
Isnt there an issue with some dzr stuff being a bit shy in their content mix, leading to possible failure within5-10 years? How do I tell which ones are good and which are substandard for the job! Any reason to use them rather than tru design plastic ones?
 
And saying you "never used them" is a very poor answer. Seacocks should be exercised (opened and closed) at least a few times each year, as a matter of routine maintenance, to preserve function. If it has not been used in a few years, that alone strongly suggests it won't work (will be jammed).
 
steve yates said:
! Any reason to use them rather than tru design plastic ones?
Click to expand...
We have slowly been replacing with Tru Design, but they had a fire in the NZ factory which caused supply problems during lock down. So whilst the heads discharge is Tru Design, the inlet had to be a DZR because the smaller sizes weren't available. I think the supply problem has been resolved now. I will replace the DZR in a few years with Tru Design. Note the 1 1/4 and 1 1/2 I think have the same size valve body, just the ends with the threads are different.

If the old valves won't come out easily, just break out the angle grinder.
 
If the skin fittings are good you could just put tru-design valves on to the existing fittings. Put a back nut on first so that you can align the valve handle to be accessible and then tighten up the back nut. Will still need to a thread sealant.
 
steve yates said:
Ah ok, if they wont fit the throhulls then it wont be blakes.
Isnt there an issue with some dzr stuff being a bit shy in their content mix, leading to possible failure within5-10 years? How do I tell which ones are good and which are substandard for the job! Any reason to use them rather than tru design plastic ones?
Click to expand...
The whole point of DZR is in the name Dezincification Resistant. Brass with arsenic in the alloy and is as good as much more expensive bronze. Plain brass (copper and zinc) as used in domestic plumbing is widely used in boats but can dezincify, although usually fittings rather than valves. They last far longer than 5-10 years and there are literally hundreds of thousands in use in boats without any problems. The "5 years" comes from a misunderstanding by people who should know better of the RCD requirement that seacocks and fittings should last a minimum of 5 years. Before that came in most European builders were using plain brass as DZR did not exist and without problems so continued to do so - and do to this day.

However now that DZR is widely available at much lower cost than bronze with similar life expectancy (ie indefinitely) it makes sense to use that. Your Blakes valves if post 1980 or so will in fact be DZR not bronze. Trudesign is a good alternative, but is generally more expensive than DZR and physically larger, although the thread and bore sizes are the same as metal fittings so are interchangeable. No advantage in life over DZR, but many have found them less prone to sticking if not operated regularly.

Hope this helps
 
The second valve is possibly from the ice box that was fitted in my 1974 built Renown outboard of the galley sink. Mine didn't have a valve, the melt water drained to deep bilge where it caused little problem. I can't remember what was used as a seacock for the sink or even where it was. I do remember that the only other hull openings were for the heads and its sink ( both Blakes cone type) and engine seawater intake, which was some kind of ball valve integral with a strainer.
 
Bodach na mara said:
The second valve is possibly from the ice box that was fitted in my 1974 built Renown outboard of the galley sink. Mine didn't have a valve, the melt water drained to deep bilge where it caused little problem. I can't remember what was used as a seacock for the sink or even where it was. I do remember that the only other hull openings were for the heads and its sink ( both Blakes cone type) and engine seawater intake, which was some kind of ball valve integral with a strainer.
Click to expand...
Yes I presume its for that, there are also two hull openings for cockpit drains, with blakes on them.
 
thinwater said:
And saying you "never used them" is a very poor answer. Seacocks should be exercised (opened and closed) at least a few times each year, as a matter of routine maintenance, to preserve function. If it has not been used in a few years, that alone strongly suggests it won't work (will be jammed).
Click to expand...
True, but she has been ashore since middle of 2018 and sailed for a year prior to that when I first bought her. Neither the heads seacocks worked nor the tap, so they were never used, but always on the list to be looked at eventually.
Actually, not quite true, I did double check they were closed in Penzance once when I grounded her on a falling tide, lying about 30degrees on the sand, to make sure the incoming tide didn‘t flood in before she straightened up and floated.
Allthe seacocks had wooden bungs attached in case of failire when I was sailing her.
 
You must log in or register to reply here.

Share this page

Top