Silver-coloured seacock - safe?

yodave

yodave

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Hi,

Been checking my seacocks and I've found one under the sink which looks as though it has been replaced reasonably recently (by the previous owner).

It's a bright 'colourless' silver - not a 'warm' silver if anything a 'cold' silver. Pretty sure that I read in PBO/Yachting Monthly that seacocks should be either bronze or plastic. So any ideas what metal this might be and ...should I prioritise a replacement before crane-in?

Photo here:

sinkseacock1.jpg


Thanks in advance.
 
Stainless steel or chromium plated.

If its chromium plated the question is chromium plated what ?
Ordinary brass or Tonval would not be so good.

Bronze, dezincification resistant (DZR) brass are both acceptable.

Plastic is fine too but I'd go for all plastic rather than mix with metal skin fitting and hose tail

The hose clip should be doubled up!
 
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I take it by it's angle that it is underwater?

If so, if in doubt replace it, It's not worth risking your investment for the sake of one valve.

If it is above the waterline, it can always be blocked then replaced, if the worst should happen.

However, it does look very similar to the seacock fitted to our saildrive, by beta.
 
sorree.... I don't see CR anywhere on it... the hose clip is a single clamp and is showing signs of rusting.. and thirdly... the skin fitting green stains are I guess a sign of leakage from above..

Skin fittings always look worse in a photo than in reality.. but 1, please double clamp if below waterline.. 2, check what is causing the green weeping stain and 3, check for a CR (Corrosion Resistant marking on the valve).. any more questions, just ask...


2 might be just a weeping hose-fitting joint.
 
First it is not a seacock - just a questionable ball valve on a through hull. I think you will find that the threads on the through hull are straight and on the valve the threads are tapered - a mismatch that doesn't allow more than a few turns.

And I agree with VicS that it should have 2 hose clamps and ideally they should be AWAB type as the perforations on standard ones cut into the hose.

I would at least find out what it is made of. And replace the rusty hose clamp with 2 good ones that are all stainless.
 
I have yet to come across a plated valve body that is either DZR or bronze. It is almost certainly some type of brass. The cost of DZR is so little more than brass that I don't see the point in buying less. Lean on the assembly to check the strength of the skin fitting and hose tail. Replace the valve and assemble with some sealant.
 
I am not an expert in seacocks but if this was my boat I would be assessing the knowledge and capability of the person who had changed the cock. just looking at the jubilee clip and th
e pipe would be telling me something. I then would weigh up the uncertainty multiplied by the potential consequences divided by the simplicity of the solution, especially if she's out of the water.
 
It's nickel plated brass. I had a couple on my sink outlets at the waterline and was also sent some by mistake when I ordered bronze. Possibly OK if outlet only just on the waterline but take the precautions reccomended already. But as Vyv Cox says, why not just put DZR one on. I agree with Mitiempo that we should get out of the habit of calling these plumbing fittings Sea-Cocks just because they have been used on a boat.
 
Agree with Ithet - Nickel plated brass ball valve, as stocked by any plumbers merchant for use in domestic water systems. OK until the brass dezincifies in salt water, when it crumbles to powder.... There is a marine version using bronze and stainless..... which still doesnt seem to me a good idea for below water line fittings.

Further indicator it is plumbing grade - the blue handle for a cold water pipe. You can get them with red handles for hot water. I am told marine grade bronze normally has white handles, but am not sure whether this is an industry standard.
 
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oldharry said:
Agree with Ithet - Nickel plated brass ball valve, as stocked by any plumbers merchant for use in domestic water systems. OK until the brass dezincifies in salt water, when it crumbles to powder.... There is a marine version using bronze and stainless..... which still doesnt seem to me a good idea for below water line fittings.

Further indicator it is plumbing grade - the blue handle for a cold water pipe. You can get them with red handles for hot water. I am told marine grade bronze normally has white handles, but am not sure whether this is an industry standard.
Click to expand...

Stainless steel ball valve from asap with blue handle:

http://www.asap-supplies.com/marine...nless-steel-ball-valve-female-each-end-405753

Note it has a stainless handle too !
 
yodave said:
Hi,

Been checking my seacocks and I've found one under the sink which looks as though it has been replaced reasonably recently (by the previous owner).

It's a bright 'colourless' silver - not a 'warm' silver if anything a 'cold' silver. Pretty sure that I read in PBO/Yachting Monthly that seacocks should be either bronze or plastic. So any ideas what metal this might be and ...should I prioritise a replacement before crane-in?
.
Click to expand...
.


Probably a domestic ball valve for fresh water so might be good for a few years.

The double clip advice is good apart from the fact that the hose ferrule is not long enough for double clips so get a longer one. Try not to get brass:D:D
 
The skin fitting may well be bronze - turning green rather than pink. A word to the wise on the hose to tail connection - stainless jubilee clips are to be preferred, and always use two....

(Clip advice already supplied in an earlier post - missed that - sorry!)
 
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Scillyboy said:
The skin fitting may well be bronze - turning green rather than pink. A word to the wise on the hose to tail connection - stainless jubilee clips are to be preferred, and always use two....

(Clip advice already supplied in an earlier post - missed that - sorry!)
Click to expand...

Unfortunately the corrosion products of both brass and bronze are green. Check out local bronze statues, compare with brass fittings in urinals, around your house perhaps, on Blakes seacocks (DZR), all green. Some bronze statues appear to me to be a somewhat lighter green shade, but not knowing their exact composition, nor that of the atmospheric pollutants in the area, this may be a red herring :)

The pink colour of dezincification comes a long way further down the road. There's a nice new example on my website here, first photo on the page.
 
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" There is a 'T' in statues. " There are two.


Your site is very interesting. If the OP had enough concern to post the question then there is no doubt that the small cost of getting the correct valve, a longer pipe tail and the correct clips will be the right thing to do.
For a few quid the to-do list is complete and peace of mind restored.
 
Lakesailor said:
" There is a 'T' in statues. " There are two.
Click to expand...

So there are:D

I left the second one out twice. Seems there are certain certain keyboard movements that the two-finger typist often finds difficult. On many forums I often read 'teh' instead of 'the' and 'remeber' instead of 'remember'. I have never found the first of these a problem but am always aware of the second, which I have done.
 
I am currently changing all my skin fittings for bronze and DZR ball valves. I have Sikaflexed the skin fittings in place and intended to use PTFE tape on the ball valve and hose tails. Is there a better/preferred sealant? Thanks

Incidentally the old skin fittings looked like they were bronze, but with nickel plated valves and brass tails which were just showing some pinkness after 7 years.

Thanks YM for raising awareness.
 
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vyv_cox said:
Unfortunately the corrosion products of both brass and bronze are green. here, first photo on the page.
Click to expand...

That's a very useful correction - thanks. I've assumed wrongly that the screws etc. which developed verdigris (sp?) were bronze. I replaced the skin fittings and valves when I bought my boat a couple of years ago, and I could only get brass at the time. I used a spiral reinforced plastic hose which leaked seawater (even with two clips - cured by a smear of sikaflex) when I tested the outflow pump pump, and the flow down the exposed thread of the skin fitting quickly turned pink!

Having read all the scare stories, and in order to sleep better at night, I invested in a set of bronze fittings, which have been sitting on the floor all summer, glowing a bronzy gold, waiting to be fitted. They might as well have been gold, given the amount they cost! Now in place for the new season, and my peace of mind is restored.....:)
 
I would be less concerned about the oft repeated 'double clip' mantra than that ply wood backing pad. When that rots, the skin fitting will leak rather badly.
 
Thank you all for taking the time to help me

Apologies for not responding sooner; my weekend didn't go as planned.

Many thanks to all who took the time to give advice or opinion. This is very much appreciated. I'm really glad that I asked; because I had initially thought that the fitting looked quite new, so was a low priority.

Looking back through your replies, the broad consensus is that I have a domestic fiting that's not up to the job ...given that I can confirm it lives about a foot below the waterline.

With less than a month to go until crane-in, I'll now proceed to source an appropriate replacement (with a straight thread), in line with the advice given on this thread. I'll also give some thought to the ply backing pad situation. My immediate thought is to give it some sort of protection for the short term, as I'm not overly keen on the idea of replacing that at the moment.

Thanks once again!
 
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