Closing seacocks when slipping.

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Sagdito

Veteran Member
Joined
Apr 17, 2017
Messages
28
Location
Australia
Vessel Name
Vivante
Vessel Make
Island Gypsy 36
About to slip my Island gypsy for the first time and was wondering if I should close the seawater engine intake seacocks before lifting out of water, my reasoning is so that they don't drain and leave the impeller dry for the restart when putting back in.
Thanks in advance for any suggestions.
Pj
 
I always close the two main engine water intake and the generator intake seacocks for quick hauls. It's probably not needed for the main engines but is absolutely needed to maintain a prime for the generator.
 
Yes, closing the seacocks when hauled is a good idea for the reasons you point out. I choose to keep all seacocks closed unless the system is in use. When we are cruising, the main engine seacock stays open, however when we get into a slip for a week or longer, it gets closed to. That helps kill off any critters trying to grow in the sea strainer. When I close the main seacock I put the engine start key on the seacock handle. Don't want to start the engine with the seacock closed. You don't need to know how I learned that lesson nor how many times I learned that lesson before I came up with this idea.

We have a condition similar to Steve. Our generator impeller would only last 30-50 hours. It seems that when we are underway, there is a vacuum generated which drains the generator intake hose, so every start was a dry impeller. If I close that seacock after each use (2x day) the impeller will not fail and will last until I net decide to change it, about 200-300 hours.
 
Interesting. In my case, the strainers and lines stay full. So it doesnt matter if I close the seacocks or not. It must depend on the strainer's configuration.

If you do this in freezing weather, remember to drain the seacock itself. Otherwise, the slug of water trapped inside the valve can crack the seacock. There is normally a drain plug on the side of the seacock for that purpose.

Ken
 
Yes. I always close all of ours.
 
"Slipping?"

Is that, by definition in Oz, what we often call "hauling"?

-Chris
 
I always open all my seacocks for haulout. Of course I only haul out for the Winter and want the systems to be dry so water will not freeze in them.
 
I'm sure it depends on the level of the impeller in relation to the water line. My generator impeller is higher than the main engine impellers while the three strainers are on the same level below the water line.
 
My engine raw water pump will prime if I leave the seacock open for a haulout. My air conditioner will not and needs to be primed when put back in the water.

For that reason, I close the seacock to the AC prior to a haulout. I don't close the engine seacock because the marina might start the engine to move the boat if they put it back in when I'm not there.
 
Thank's guys looks like I will keep them closed.
 
I try and remember to operate all my seacocks once hauled out. Just so I know I they can be closed! Otherwise the only time I close them is to clean the strainers, which for the engines, and the Naiad cooling water intake happens from time to time while I am in the water.

But I did replace all hoses and I have good quality double clamps on them. Some of my seacocks are not easily accessed, and running around opening or closing them would be a PITA.
 
"Slipping?"

Is that, by definition in Oz, what we often call "hauling"?

-Chris
Yes,it is.
If you do close them, remember to open them. The delay while the rw pumps draw in water is worry enough.
 
About to slip my Island gypsy for the first time and was wondering if I should close the seawater engine intake seacocks before lifting out of water, my reasoning is so that they don't drain and leave the impeller dry for the restart when putting back in.
Thanks in advance for any suggestions.
Pj
Having just bought a GB32, my very first bigger motorized boat, your question makes me aware of all the learning I must do. Here in MI, we disconnect lots of hoses at the seacock and dip them in non-toxic antifreeze and let the system suck it through. We used to have only one -- "Red Pop" we call it. Now we have "Blue Pop" and "Purple Pop." Purple protects down to -60. All this nomenclature started because we have a local soft drink brand, Faygo, that has a drink called Red Pop. For us here in Detroit area, hauling the boat for the winter is a real cultural experience.
 
"Slipping?"

Is that, by definition in Oz, what we often call "hauling"?

-Chris
Yup, hauling is the word, at least here in Detroit. Oh, by the way, locals here call the place where they tie up in a marina a "boat well." I never heard that until I came here. Elsewhere it was called a "slip." I guess everything, including politics, is local..
 
Yes, closing the seacocks when hauled is a good idea for the reasons you point out. I choose to keep all seacocks closed unless the system is in use. When we are cruising, the main engine seacock stays open, however when we get into a slip for a week or longer, it gets closed to. That helps kill off any critters trying to grow in the sea strainer. When I close the main seacock I put the engine start key on the seacock handle. Don't want to start the engine with the seacock closed. You don't need to know how I learned that lesson nor how many times I learned that lesson before I came up with this idea.

We have a condition similar to Steve. Our generator impeller would only last 30-50 hours. It seems that when we are underway, there is a vacuum generated which drains the generator intake hose, so every start was a dry impeller. If I close that seacock after each use (2x day) the impeller will not fail and will last until I net decide to change it, about 200-300 hours.



I figured it out the hard was too.
 
Seems like an east coast thing to close the seacocks, so obviously safe to do so.
Here on the west coast, where our boats remain in their slips over the winter (slipped?) I know of no one who closes their seacocks on their annual haulout.
A few surveys ago the surveyor commented on my seacocks as unusual in that he could actually move them, as most boats he had surveyed never moved the seacock handle.
I have never had the experience Tad reports. In fact I have never changed a generator impeller, don't carry a spare, though that is only through lack of attention, not deliberate. I do use my generator regularly, perhaps 50 hrs a year, over 24 years in this boat. I guess it never loses its prime. The mains always start up and gush water right away. The glass on top of the strainers always show water.
 
Yes,it is.
If you do close them, remember to open them. The delay while the rw pumps draw in water is worry enough.

Our dockmaster told us very early on in our boating lives that the best way to remember to open them is to hang your keys on the cock handle. That way, you will never be able to start the motor with them closed. :thumb:
 
What is slipping? Going to your slip? Or do you mean haulout?

I always close my seacock as soon as the engine is shut down. As I generally do a seacock check and replace the impeller when I haulout, all rawwater is drained from the system. I always check the water flow from the wet exhaust and never had any problems.
 
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