Should I replace seacocks?

peoples1234 · Mar 4, 2013

I just pulled all of the seacocks and thru-hulls from my boat (Beneteau 321). I have no doubt that they were the factory installed seacocks from 1995. One was stuck in the closed position even though the handle worked smoothly, one thru hull snapped off when I tried to thread the seacock off of it. All of the other had corroded elbows that broke when the hose was removed (total of 6).

I am so glad that I decided to look into them even though the surveyor said they were acceptable in his report. I will be replacing them properly with backing plates, and flanged seacocks.

My point is that if you have any doubt, replace them.

Malcolm/Trilogy · Mar 4, 2013

Thru hulls and ball valves

I have had a Passage 42 since 1996 and live in Hong Kong (China) - here the weather is unkind to everything - we have temperatures of 16c (61F) for 10 months of the year (and usually over 28c (82F) for 6 months of the year - added to that we have humidity over 70% for up to 11 months of the year - so much so that even 316 stainless is not immune to discolouration - so things such as thru hulls and ball valves take a toll. I have in the last year had to cut thru the thru hull fitting nut because the bronze ball valve (fitted by Hunter) crumbled and could not be removed successfully from the fitting (not bad for 16 years in thsi climate) I have also replaced four ball valves in the engine room although the thru hulls were fine (two I removed and cleaned and refitted).
So I would suggest while the boat is out of the water test each one and make an individual decision as to the plan for each. For example for one of the cockpit drains I had to cut the handle and fitment of the side of the ball valve body in order to be free to rotate it and remove it from the thru hull - not an easy job. However, I found a bronze replacement made by a Japanese company that was not so large and could be fitted without damaging the thru hull for the prop shaft.
Take time and check and test each one before you decide.
Malcolm

Steve Dion · Mar 4, 2013

McZube:

If you are going to the trouble of replacing the thru hull, you may as well bite the bullet and change them all out. The one in the head for the sink drain is a bugger. The good thing about it is the fact that it is not under water. You don't have that many fittings to replace and it is a lot cheaper to do it now than when the boat sinks or there is a failure. Be sure to use good quality bronze (not brass units).

I would also suggest that you replace all of the back plates. Yours are probably plywood (like most of them were).

BigEasy · Mar 4, 2013

I had a '88 Hunter 33.5 that has a mixture of gate valves and ball valves mounted directly on thru hull fittings. I changed them out when the boat was about 10 years old. Used an angle grinder to grind off the mushroom shaped thru hull on the bottom and popped out the valve and remaining thru hull from the interior in quick fashion. I also like the idea of using the Groco flanged adaptors for replacements. It eliminates the mismatched threads of the thru hull fitting and ball valve. If the valve requires replacement in the future it defintely simplifies the process. Should be able to install a new 3/4" thru hull, groco flange, & ball valve for about $100. per valve location if you do it your self. Definitely time to do this if the boat is over 20 years old!

Watermusic Live · Mar 4, 2013

Visual Inspection should be ok. Look for plastic fittings or other non-factory modifications, rust. I would focus on the seacock before making a blanket decision on "all thu-hulls". Maybe he's right, or just conservative. 1980's is a long time.

Watermusic

Watermusic Live · Mar 4, 2013

Not Bread

71175 said:
Yes, especially if their the plastic type.....and several years old... FYI, you can change them while the boat is in the water.....just use bread. screw off the valve, stuff bread in the hole, (take your time) place plumbers tape on the threads and reinstall the new valve.

They make a emergency plugging calk like beezwax. Just open the top and shove it over the nipple, more than once.. it will react with water and harden. Safer.

However, if they're all 1980's I'd do it anyway as preventive maintenance. Lt's all about the $$.

Watermusic

Benny17441 · Mar 5, 2013

I have nothing against gate valves except that they may foul easier than ball type ones but as long as you frequently inspect clamps and hoses neither will constitute a safety issue. I do have a problem with old valves irrspective of the type. The tend to corrode both from oxidation and stray electrical current. If your boat is older than 20 years and still has the original valves go ahead an thoroughly inspect them for corrosion and operation and if you find one that needs replacing or if any of the thru-hulls needs replaceing then get them all done at once as it will definitely be more cost effective. Corrosion will make the metal brittle so to test the integrity tap lightly with a small hammer.

shannon28 · Mar 5, 2013

moehorenfeldt - FYI

The surveyor stated ""keep an eye" on the gate valves, as the insurance people prefer they be ball valves. I "exercise" them 2ice a year, to insure that they move freely,"

I'm not sure what the surveyor was thinking. In the US I believe the surveyor would have told you to replace them ASAP.

If your boat has always been in fresh water then the gate valves should be OK. In salt the gate and stem could well have evaporated and you'd never know it.

It's hard to "keep an eye" on the inside of a valve unless you

arelic1949 · Mar 5, 2013

buy a used copy of This Old Boat, get prices on buying the seals and balls, or the entire unit. either way, lube 'em good, and operate them often<.>

shannon28 · Mar 5, 2013

I don't know, I have always had this thing about the holes in my boat and the devices that keep the water in and out. I always hear people talking about the fact that they've had xyz valves and never had a problem. I've seen 40 year old boats that are pristine, still afloat with gate valves that haven't worked in 35 years. It seems everyone has their own comfort level on this issue. I feel that old murphy is on steroids on a boat. And you never have a problem on a boat till you have a problem. And they always seem to occur 50 miles offshore or in the middle of a storm.

So here's my simple list of seacock/thruhull choices:

1. A flanged seacock (ball or cone) like Apollo, Buck-Algonquin, Groco, Perko, Spartan.
2. Groco's flange (issue exposed threads) also, make sure you get a UL 1121 approved ball valve.
3. Thru-hull/ball valve combination (issue exposed threads and simple locking nut for support) at least use the Groco combination threaded thru-hull.
4. Forespar's 93 (issues material and design) serious degradation in water, check the Catalina websites for problems.

Check out Compass marine's site or on Youtube look up seacock failure. But remember the biggest problem is not "static load" but impact. One or two hits with an 8 lb weight will do more damage than a 500 lb weight any day.

If in doubt, the bottom line is go with a bronze flanged seacock.

Rick Sylvester · Mar 8, 2013

If your thru-hulls and valves are from the factory

I doubt seriously that they are true sea-cocks. I'll bet they're valves screwed directly onto mushroom fittings.

BigEasy is spot on. You very likely have some very mis-matched threads, kinda like the first two pictures I've included here. Care to guess how many turns that valve took to fall off? I damn near crapped my pants.

Love the Groco flanged adapter design.

Maine Sail · Mar 9, 2013

Rick Sylvester said:
I doubt seriously that they are true sea-cocks. I'll bet they're valves screwed directly onto mushroom fittings.

BigEasy is spot on. You very likely have some very mis-matched threads, kinda like the first two pictures I've included here. Care to guess how many turns that valve took to fall off? I damn near crapped my pants.

Love the Groco flanged adapter design.

Rick,

Those are some SCARY pics... Would you mind sending me those images and allow me to use them in my seacock article when I reference mismatched threads? I will give you full credit for the photos.

compassmarineservices at gmail dot com

Rick Sylvester · Mar 9, 2013

Maine Sail said:
Rick,

Those are some SCARY pics... Would you mind sending me those images and allow me to use them in my seacock article when I reference mismatched threads? I will give you full credit for the photos.

compassmarineservices at gmail dot com

No sweat, in fact, at that time I was inspired by your most excellent website. You sharing your knowledge was REALLY helpful. I'll get 'em to you this weekend (I'm not home right now.)

Scary is right . . .

Chris Patterson · Mar 10, 2013

Wow. Not only do you have only two, or three threads holding, they look galled.

D.L.Bland · Mar 10, 2013

pull 'em, pitch em, Look the old style will give out sooner or later, the new ( ball valve ) style are way better, a hole in your hull can sink your boat in a real jiffy, replace 'em b4 puttin the boat back in the water Captain!

Rick Sylvester · Mar 12, 2013

Yup. They were.

Chris Patterson said:
Wow. Not only do you have only two, or three threads holding, they look galled.

It's those mismatched threads.

I'm always amazed (after this experience) that boat owners will be diligent about double clamping hoses onto a fitting such as this.

Makes me think of arranging deck chairs on the Titanic.

Pat · Mar 12, 2013

This is probably a bad question. With the advent of our club's installation of a pump out station, I no longer use the thru hull for my head in the O'Day 272. The last time I used it the handle seemed frozen so I just left it in the closed position.. This is a bronze groco
thru hull but I feel like it should be replaced. My confusion is whether there are two parts to this 1 1/2 inch thru hull...i.e. the body and the ball valve...are these two part
valves or is it possible I could reuse part of it...or should I just replace. Or, should I worry about it since it is closed and just continue to use the pump out station? Pat

Chris Patterson · Mar 12, 2013

Let's see a picture of what you've got.

Rick Sylvester · Mar 13, 2013

That's the problem.

McZube said:
I will ensure that each seacock is sufficiently threaded onto its thru hull.

I'm guessing that what you are calling a seacock is actually just the valve. An actual seacock is an entire assembly that will include a large flange which can be securely attached to the inside of the hull (Maine, help me out here.)

If so, the valve threads (tapered) are mismatch with the thru-hull threads (straight) so that they cannot thread together properly.

Before you make any decisions I strongly urge you to review Mainesail's excellent website on this issue.

Thanks for the kind words.

Should I replace seacocks?

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