At what age should a boats seacocks be replaces or at least removed and checked.

[dial-a-monkey]

Found this on the web - There's a lot of interesting information about Beneteau throughhulls - if it's of any interest?
http://mymoorings.com/Notes/Data/Domino/HTML/SA192007.pdf

TESTING THRU’HULLS
We have heard it said that you just need to look for the copper red color on the through hull. But unless brand new they will all be de-zincified on the surface and showing a copper red color. What we need to know if how deep it is. You can use a knife or file to scrape the exposed surface of the flange and check the depth of the red before you get to bright yellow of the brass. But that still does not prove what its like inside where it normally fails. The best test is “the hammer test”. Give it a tap on the side with a medium weigh hammer. If it breaks off it was close to failing so needed immediate replacement anyway. If it does not break it is OK for now. We don’t know if it’s half corroded away but at least we know its not 99% gone. This test has proven quiet successful and I don’t know of any other way it can be done without removing the through hull for analysis. This should be done on every haul out, once the boat is 2 or 3 years old or earlier it the through hull looks suspicious in any way. It’s best not to do it in the water although I have done it when I was particularly worried about the condition just prior to a long distance deliver. When we did break one off in the water we could at least say it was easier to sort it out with the boat on the dock than it would have been for the skipper in the middle of the Atlantic.

 

[vyv_cox]

What's peoples opinion of this one? It's a Beneteau setup, about 4 years old,

I'm wondering if the pink is dezincification?

The Ball valve is Sferaco ACS No 4 ACC Brass CW 614N (Tonval brass also called CW617N or CZ122 or OT58) + EN 12165(chromed)

It seems? the Beneteau spec for the through hulls was changed in 2006/7? (due to early failures?) from = CuZn40Pb2(CW617N) to CuZn36Pb2As @ 2% arsenic DZR protection. The through hulls seem to be made for Beneteau by Plastimo, and have a rubber sealing ring rather than chemical sealant.

The washer beneath the nut may have a little surface dezincification, difficult to tell. The valve is certainly susceptible to dezincification but a little surface reddening is not sufficient justification to change it out. In the end it is the strength of the fitting that is the important factor, so test it by heaving on the hose to see if it takes your weight. Many failures have occurred when people put weight on the fitting or hose when doing other work.

Incidentally, in your specification above the '2' refers to the lead content (2%). the arsenic content is only around 0.1%. Lots more info on my website at http://coxengineering.sharepoint.com/Pages/BrassandBronze.aspx

 

[rgarside]

Finally got the bottom end of the valve and the lock nut off the end of the skin fitting. Required a bit of experimentation to find suitable pipe pliers / pipe wrench to get any purchase on the end of the valve, and then quite a lot of heat [avoiding melting all the surrounding bits of plastic] before it finally yielded to persuasion.

The skin fitting passes all the "swing on it" and 'hit it with a hammer" tests, but shows some surface pinkiness on the external threads. I have emeried the end of the fitting to bright metal in the attached photo. Changing the skin fitting would be a major nausea, so I think it will just be a valve replacement this season.

 

[macd]

Glass-reinforced plastic fittings appear to be a better bet than even Admiralty bronze (which the tail was).

"Admiralty bronze" is almost as fraudulent a description as "Tonval": it's brass, with just 1% tin to inhibit dezincification, which is why it's commonly also called Admiralty brass.
And regarding all the references to Blakes seacocks: it's evidently worth reminding ourselves that if made in the last 30 years or so, they're not bronze either, but DZR brass.

 

[GrahamM376]

Nasty shock this morning. Removing no.4 of 5 underwater through hulls and one broke up. We had a survey last winter and all were hammer tested satisfactorily. Surveyor did mention that after 25 years it would be prudent to change them so I'm following his advice with Trudesign.

The photos are of the forward heads outlet, on a 1988 376. Seacock and nuts came off OK but when I stuck the stilson handle down to give it a wiggle, it fell apart with not much pressure. As you will see, the threads give no real cause for immediate concern, just a tinge of pink.

View attachment 38780View attachment 38781

 

[sunshinesailing]

Thru hull replacement

Hi Mocruising.
Knowing the age of your Hallberg Rassy and your upcoming transatlantic it would be prudent to change them all before your departure. You will sleep better on the crossing. Your insurers may insist when you up grade for the crossing. There are no haul out facilities in the Atlantic should something crucial fail. It is a big job, we also have about fifteen but they have all been changed. We are now in St. Augustine Florida. Maybe we will see you on this side of the pond. The Intra coastal waterway is a bit of magic.

 

[silver-fox]

I have a 24 year old Moody with a couple of original seacocks and some cheaper ones that were replaced by the previous owner I reckon about 7-8 years ago. Faced with several failures - ie you could turn the lever but it was pretty evident that the valve was jammed - and some of the new seacocks suffering from corroded handles when the valves seemed OK, I have replaced them all, that is all the through hulls and all the seacocks with composite ones.

Several owners recommended Tru-design brand from New Zealand and that is what I have used, Leesan resell them in the UK.

Here is the link for anyone that may be interested.

http://www.trudesignplastics.com/products

During replacement one tail sheared off, as we attempted to remove the hose, so no regrets about the decision to them all

Its too early for me to recommend, but one thing is for sure, what ever problems I may experience - no corrosion or de zinc-ing problems now!

 

[GrahamM376]

The skin fitting passes all the "swing on it" and 'hit it with a hammer" tests, but shows some surface pinkiness on the external threads. I have emeried the end of the fitting to bright metal in the attached photo. Changing the skin fitting would be a major nausea, so I think it will just be a valve replacement this season.

I think you're giving yourself a false sense of security. Because the pinkness disappears when emeried it only disguises the problem.

I ran a disc cutter through my knackered fitting and was surprised the corrosion doesn't show up where the surface had been polished by the disc, maybe Vyv can explain why. Have a look -

View attachment 38800

 

[vyv_cox]

I ran a disc cutter through my knackered fitting and was surprised the corrosion doesn't show up where the surface had been polished by the disc, maybe Vyv can explain why.

I can only assume smearing of the more ductile brass over the brittle copper-rich phase. If you abrade the surface back with wet and dry on a flat base, done wet, the smeared metal will be removed, revealing the true condition beneath.