seacocks

[carlager]

I am considering replacing the seacocks in our Beneteau 36cc, built in 2003.

The seacocks have never been replaced and I was wondering if is time to do it now.

Has anyone got experience with this ?

[jibstay]

I replaced all the seacocks in my Beneteau 473 in November.

How can I help?


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[jibstay]

Regarding if it's time, I was burning through zincs every month. I installed a galvanic isolator, which solved that problem, but decided to replace the thru-hulls and ball valves, just to be safe. I'm glad I did because they were pretty pink.


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[Scott Berg]

Don't skimp on either the materials or the technique; Groco has some of the best information and make excellent products... there is a BIG difference between a true flanged seacock and a ball valve screwed onto a thru hull fitting. Take the time and do the job right; thru-bolt the seacocks with backing plates and then screw the thru hull fittings into the seacocks...

http://www.jamestowndistributors.com...Large/538a.jpg

[carlager]

@Jibstay
How old is your Beneteau 473 ?

[leftbrainstuff]

Originally Posted by Scott Berg

Don't skimp on either the materials or the technique; Groco has some of the best information and make excellent products... there is a BIG difference between a true flanged seacock and a ball valve screwed onto a thru hull fitting. Take the time and do the job right; thru-bolt the seacocks with backing plates and then screw the thru hull fittings into the seacocks...

http://www.jamestowndistributors.com...Large/538a.jpg

+1

Only way to go. I prefer bolting the thru hull to the backing plate not thru the hull to avoid another hole in the hull. (On the right in the diagram)

We only use Groco bronze sea cocks. We also have a single Marelon sea cock for our water maker. It's on the list of things to replace at next haulout. Nothing wrong with Marelon.

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[kas_1611]

After reading the horror stories about sub standard thru-hulls and seacocks in Yachting Monthly then discovering that we had the same type of cheap brass fittings we took the plunge and replaced all of ours with Marelon with the exception of the engine water intake which had to be DZR (and has a proper certificate).

Given we have a 2010 build boat I can heartily say "better safe than sorry".

Unless you are 100% sure you have proper bronze or certified DZR fittings assume they are cheap brass (freshwater plumbing) fittings and "rip 'em out" and replace them.

Keiron

[Lepke]

I'm 67 and have been in ships and boats most of my life. Properly protected thru hulls should last the lifetime of the boat. My 1942 boat has many 1942 thru hulls that are in excellent shape. On the first haul out, all were disassembled, cleaned, lubed and reinstalled. One was destructive tested. As long as zinc protected and no major electrical screw ups, they will give fine service.

[carlager]

Our Beneteau Oceanis 36cc was built in France in 2003.

We bought it in 2010. The survey report states that seacocks are made of bronze ("Bon etat des passe-coques en bronze")

An earlier report issued in march 2009 also concluded that the seacocks are made of bronze ("Les passecocques en bronze ne presentment pas de corrosion active"

I assume the seacock valves are made of bronze

Can this be confirmed from the attached photo ?

[kas_1611]

Originally Posted by carlager

Our Beneteau Oceanis 36cc was built in France in 2003.

We bought it in 2010. The survey report states that seacocks are made of bronze ("Bon etat des passe-coques en bronze")

An earlier report issued in march 2009 also concluded that the seacocks are made of bronze ("Les passecocques en bronze ne presentment pas de corrosion active"

I assume the seacock valves are made of bronze

Can this be confirmed from the attached photo ?

With those red handle I would assume they are NOT bronze. The cheap brass ones we replaced were fitted with red handles and the certified DZR replacement has a GREEN handle. Unless there is some casting references in the valves and particularly a large CR (Corrosion Resistant) I would play it safe and assume brass not bronze.

Originally Posted by Lepke,2072071

My 1942 boat has many 1942 thru hulls that are in excellent shape.

Lepke, you have a boat from the days when quality overruled costs so you would have had quality bronze fittings from the start. And yes you are correct these should last the lifetime of the boat if looked after. Sadly in recent years costs have become king and with the ridiculous EU RCD rules stating "thru hulls should last at least 5 years" boat builders have been fitting cheap freshwater fittings even though these have been shown to fail after less than 5 years.

Keiron

[Jason Flare]

Originally Posted by carlager

Our Beneteau Oceanis 36cc was built in France in 2003.

We bought it in 2010. The survey report states that seacocks are made of bronze ("Bon etat des passe-coques en bronze")

An earlier report issued in march 2009 also concluded that the seacocks are made of bronze ("Les passecocques en bronze ne presentment pas de corrosion active"

I assume the seacock valves are made of bronze

Can this be confirmed from the attached photo ?

To be clear the three items in the picture are ball valves, not seacocks. As mentioned earlier seacocks have a flange at the bottom which bolts to or through the hull.

Groco makes an IBVF adapter that can be screwed over an existing installed thruhull to turn a thruhull/ballvalve setup into a seacock.

It is important to know the difference between straight threads and tapered threads. Straight threads should not be used with tapered threads, the reason being that a tapered thread fitting will only catch a straight thread fitting by a few threads before it's tight.

The IBVF adapter provides a flange to attach to the hull, (usually with the addition of a backing plate to add thickness to the hull,) and it provides a straight female thread to attach to the straight male thread of the thruhull, and a tapered male thread to attach to the tapered female thread of the ballvalve.

There is some clear concise info on the Internet. The clear objective when installing this is to us similar threads. In the US we use NPS and NPT. National Pipe Straight and National Pipe Tapered.

[travellerw]

I will throw out another option since no one mentioned it.

Consider Marelon for both the Seacock and Mushroom head. They never corrode and you don't have to worry about protecting with zincs. They won't/can't blow out in the event of a lightening strike...

There are 2 versions.. One with a bolted flange just like the Groco bronze fittings and one with a glued flange. I prefer the glued flange to avoid extra holes in the boat and not require a backing plate. Here is a link to the defender product page for both.

Forespar Marelon 93 Series Ball Valve / Mushroom Thru-Hull Fitting - 1/2"

Forespar MF 849 Marelon Seacock

[nigel1]

Those valves certainly look like brass (chrome plated). Certainly look very similar to the ones I replaced on my Bene 473 a couple of years ago.
Of the valves removed, about 30% of them were showing signs of dezincafication.
All the old thru hulls, valves, elbows, hose nipples etc I replaced with DZR fittings.
In the UK, a good supplier for these are
Valves and Spares : CR (DZR) Brass

[GordMay]

Beneteau Responds to Seacock Query

Beneteau wrote a detailed response to our (Practical Sailor) recent query from a reader regarding seacocks in his Beneteau (“Seacock, Through-hull Caution” Mailport, PS July 2017). We are continuing to look at seacocks and seacock materials. The last Practical Sailor in-depth report on seacocks was in 1994, so this is long overdue. If you have a relevant seacock story to share, send it to the editor at practicalsailor@belvoir.com.

Here is Beneteau’s statement.

“As they are distributed throughout the world, all Beneteaus are built to the stringent standards of CE certification. CE is the most widely recognized official global standard, and one that is mandated as legally necessary by dozens of countries. The CE directives and legal requirements are used as the reference for the materials and systems needed in order to build Beneteaus.

“CE carries the weight of law in many jurisdictions, and Beneteau observes these; along with the legal requirements of governing bodies such as the US Coast Guard for the North American markets.

“For well over a decade, Beneteau has been installing through-hulls and valves made of a duplex brass alloy which is approved for use in sea water, and which are sourced through a respected supplier.

“Prompted by interest from a BoatUS member, Beneteau recently sent samples of the through-hulls and valves to be tested to confirm that they exceed the specific CE requirements of ISO 6957, the rule governing such items for corrosion issues. The testing was performed by the independent scientific laboratory of CETIM, and the positive results prove the examples met the ISO standard.

“As with many materials submerged in seawater, over years brass alloys may deteriorate due to chemical or electrical reaction (electrolysis), sometimes at an advanced rate due to external forces. Electrolysis may also be caused by stray current coming from the boat’s electrical system or from shore side sources (such as docks or surrounding boats).

“Electrolysis may also be the product of dissimilar materials in the water that create an electrical current that results in corrosion (batteries, metal bulkheads, etc).

“To our knowledge based upon over a hundred thousand boats produced, serious corrosion on through-hulls is episodic, and in our experience the incidence of failure is very, very rare. And those limited episodes can normally be traced to some key contributor; such as stray current, improper wiring, failure to inspect on an annual basis, lack of maintenance, etc.

“Beneteau confirms that it is mandatory to have a competent professional perform a thorough annual inspection of all underwater appendages, items and surfaces for function, integrity or performance, and that includes through- hulls and valves. The inspection of the through-hulls should be undertaken from both the inside and the outside of the hull looking for any color change.

“We also require that there must be regular replacement of the protective zincs anodes (or magnesium if in fresh water). In the case of rapid deterioration of anodes, the cause of such activity must be investigated and a fix for stray current or the exceptional presence of dissimilar metals must be addressed. In some extreme cases it is not uncommon to have anodes erode within a matter of a few weeks. Those examples require extra anode protection or more serious remedies, and expert professionals should be consulted in such instances.

"In some cases it may be necessary to replace through-hulls after years of use, which in those occurrences are considered by Beneteau to be normal maintenance. There are also examples of through-hulls which, due to standing condensation or a leaking connection, visually appear to be severely degraded on the surface, only to find that after a short minute or so of polishing they are fully structurally sound, functional, and visibly improved. With proper maintenance and vigilance, through-hulls and valves will remain reliable and secure.

"As a general reminder, it is recommended that boaters close all through-hulls upon leaving any unattended vessel."

Wayne Burdick

President, Beneteau Inc.

➥ https://www.practical-sailor.com/iss...y_12456-1.html

[rbk]

Originally Posted by carlager

Our Beneteau Oceanis 36cc was built in France in 2003.

We bought it in 2010. The survey report states that seacocks are made of bronze ("Bon etat des passe-coques en bronze")

An earlier report issued in march 2009 also concluded that the seacocks are made of bronze ("Les passecocques en bronze ne presentment pas de corrosion active"

I assume the seacock valves are made of bronze

Can this be confirmed from the attached photo ?

They could be stainless but unlikely. More concerning is the mixing of NPS and NPT threads you most likely have going on. the Thru hull is usually NPS and the elbow NPT. Some manufacturers do make a combo/dual thread thru hulls, but again chances are they are mismatched.