Preventive Maintenance - Seacocks

My first posting and let me start by expressing my appreciation for your advise. I keep my boat in the Low Country of South Carolina. I have a concern that my seacocks were constructed of inferior material and have a history of shorten expect useful lives. I want to have them inspected and replaced if needed by the most qualified boat yard. In area from North Carolina to South Florida I am looking for recommendations for a boat yard with proven experiences with this type of problem and would like a fair price but not if it means sacrificing quality of work. Again the group’s advice is greatly appreciated.

What brand of seacocks? Picture? Why the concern?. Any boatyard can replace them. I had four replaced in about 1.5 hours.

Beneteau usually uses seacocks made of DZR Brass. I wouldn’t trust it more than about five years. This is a common practice in Europe but US manufactures usually use bronze or plastic which can last the life of the boat.

DZR Brass is much more yellow than bronze because it has a higher zinc content. It has a lower zinc content than regular brass which allows it to be used in contact with salt water for some time but not forever.

Post a photo.

There are several design and material problems with valves used as seacocks:


Seacocks should be made of bronze (brass corrodes in sea water), have proper straight threads on the end that screws into the thruhull (normal tapered threads won't screw in far enough to be safe) and be either ball valve design with teflon seats or tapered plug type.



Do not use gate valves, brass valves or valves with a tapered thread on the bottom. Thruhulls which can just be a straight thread nipple sticking up that a proper straight thread valve screws into or a complete valve assembly should be installed with backing plates for strength.



This website tells you almost everything you might want to know about thru hull valves: https://marinehowto.com/category/plumbing/


David

Hi Catfan46,

I found a reference to your specific inquiry in the Aug 2018 issue of Practical Sailor (https://www.practical-sailor.com/is...neteau-Responds-to-Seacock-Query_12456-1.html)

Without personal experience with either a Beneteau, nor any boat built to CE certification, I have no idea if your Beneteau truly has a CE certification, or is simply "...built in accordance with CE standards" as the above reference states. Therefore, I can't state with certainty what the materials Beneteau uses in it's seacocks.

Having said that, and after attending a Beneteau boat show presentation that had several seacocks on display, I believe that HopCar is correct-the basic material of your seacocks is brass, vs bronze. The Beneteau seacocks are, however, nickel plated, for whatever that's worth.

So, your concerns are justified. However, perhaps not to the point of rushing out and replacing all your thru-hulls "just because". The Beneteau response above also correctly suggests that thru-hull failure is more likely due to poor maintenance and corrosion control than it is materials.

For what it's worth, I would suggest careful inspection and maintenance of your existing thru-hulls at your next haulout, and proceed from there. I would further suggest that with adequate care, your existing thru-hulls should lead a long and happy life.

Regards,

Pete

We have replaced some when the boat was pulled at Wayfarer Cove marina in Arapahoe NC. We also have lubricated and exercised existing ones and discovered that they did not need replacing. It is now part of our maintenance program to keep them lubricated

Brass is easier to machine than bronze so brass items will cost the boat assembler less.

Even fair to mediocre builders strive to keep costs down.

I would want one heck of a survey on a boat assembled with brass underwater.


Figure perhaps $250 each to purchase and have installed tapered bronze sea cocks securely bolted into the hull, a bit more for new thru hulls , if the original are not comparable with the new sea cock.

Zimmermans Marine, Charleston, SC - Steve Wallace. He will come to your boat and give you knowledgeable advice. They don't have a lift at Charleston Harbour Marina (Patriots Point) but use Charleston City Boatyard up the Wando River for haul outs if needed to change thru hulls.

Thunderbolt Marine -Savanna area. All facilities on site.

Neither of these are cheap but they are very reputable & reliable