Seacock maintenance

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Chris Foster

Senior Member
Joined
Oct 12, 2007
Messages
280
Location
USA
Vessel Name
Thea
Vessel Make
46 Grand Banks Classic
If things go to plan, I'm going to pull the boat in the next week or so for bottom paint & zincs.*

I'd also like to remove and clean up the seacocks that supply engine cooling water.* They are getting pretty stiff, and have relatively flimsy handles compared to the other seacocks on the boat.

I've never pulled out a seacock before.* I know they use straight threads instead of tapered ones, but I don't really know how they're removed and reinstalled.

Advice, please??

Thanks in advance...

chris
 
A Thru hull is what stickes thru the hull material, a real seacock is thru bolted into the hull and the thru hull simply screwed in with Dolphinite or some other removable (not 5200style) sealant.A thru hull can easily be removed without disturbing the sea cock with the right tool, GROCO..

Seacocks are two styles . some will have a SS ball that usually can be lubed by simply removing the plugs either side and pumping in (grease gun) a good waterproof lube.

The cheapest grease and gun is from the outboard guys , for lubing underwater fittings.

The marine Std is a bronze seacock with a tapered plug.
These are far superior to the hardware store SS as the passage thru is always full sized.

When in the water they can be lubed like the SS , but a huge advantage to a cruiser is they can be easily/quickly / cheaply rebuilt.

The nut and lock nut are removed and the barrel removed and cleaned.

Fine valve grinding compound and a MINIMUM of re-lapping will create a perfect seal if the unit was scratched.

BEWARE , bronze is far softer than auto valves so not much is required.

Clean everything , lube and reassemble.

A Bronze seacock will be so easy to operate it can frequently be cable operated.

Any seacock MUST be bolted in , and 3/8 bolts are the norm.

FF

-- Edited by FF on Saturday 17th of October 2009 05:30:47 AM
 
When we removed all of mine, we just used an angle grinder and ground off the outer part of the thru-hull. It was much faster and cheaper than fighting to unscrew things that were welded together with age. Then you just unscrew the rest of it after removing it from the boat, and use a new thru-hull when re-installing. If you decided you need new seacocks, I highly prefer the Groco line.

-- Edited by Keith on Saturday 17th of October 2009 06:05:51 AM
 
Oh, jeez, don't even talk about the $$$ of having to replace ... I'm hopeful that FF's clean/lap/lube process will be enough.

Over the last couple of weeks I've discovered that all of the job prospects that I'd been assured would be just waiting for me this fall have all been hoped and changed to death... so the money supply is running mighty low.* Fingers are crossed that I can find a boatyard manager willing to make me a heck of a deal for a haul and paint*just to keep his guys busy for a couple of days.

*
 
You can get really good deals on used equpment on E-Bay and used / consignment shops. I've both bought and sold on E-Bay. Remember that almost anything you take off your boat will be bought by someone else. When I replaced my old rubber cone seacocks with Grocos, the old ones were purchased immediately when I put them on E-Bay. Ditto for an old magnetic compass, a Groco EB toilet, round hull strainers, etc. I'll post my list of used / consignment dealers in another post.
 
Hi Chris,

Give Pat a call in La Conner. South end of town about a mile south of the Rainbow Bridge. He may be through w the barge and be wide open. Lattitude Marine is on Indian land so I think you can do things one cannot do elsewhere. Call me.

Eric Henning
 
Under general discussion there is a discussion about pulling a boat moored in LaConor.

I would pull at a yard that will let others and myself do work in their yard, so you can do some of the work and/or hire others if things get tough.* I would not put my boat at the mercy of a yard.* I do 80% of the grunt/dirty work myself, and I have fired some yard help.* *Also I would pull at a yard that is close to where you live/work so you can check and keep a tally of their work/time and ask a lot of question as there is a lot you can learn for next time.

I think June in the PNW is the best time as its not so cold, rainy, and windy especially if you might need to do some epoxy/bottom work.*
*

*


-- Edited by Phil Fill on Tuesday 20th of October 2009 10:21:04 AM
 
I'm scheduled to be hauled at North Harbor Diesel here in Anacortes.* They have an indoor shop to apply the paint.* They're OK with my doing work at the same time - main restriction is that they do the bottom painting.

After really looking at the raw water supply, discovered that they're not real seacocks - the through hulls go to inline ball valves, and the strainers mount on top of them.* They don't appear to be repairable.* So replacement looks like a definite po$$ibility.*
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So another related question for the gurus:* how do the straight threads on the through hulls actually seal?* Tapered threads are obvious... but I don't see how the straight ones actually prevent leakage.* I don't think there's an O-ring or other type of seal in them.* Are the threads just cut precisely enough that they don't leak, or do you apply some thread sealant before installing, or ???

*
 
Thanks, Mike.

That's exactly what I needed to see to understand how the whole process goes together.*

Will be interesting to see what exactly I have when I get it all apart.* The valve itself appears to be marine grade with straight threads, so I don't think it's the worst case scenario.*
 
Hey Mike,
VERY nice work on a resource that the rest of us can use. Are there any other subjects you have covered this way?
Steve
 
I prefer Permatex #2, the non-hardening type for sealing straight thread connections.
 
I have to install two thru hulls. I just got in my TH's (NPS),*and my 90 degree barbs (NPT)-*all bronze. It looks like I need a coupler of some sort. I looked at Groco and Jamestown without finding anything. Any ideas?
 
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Dont delay,have the yard do the job,any problems its down to the boat yard! Just had all mine done,we can*forget about them! Good Luck**
 
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