question about seacocks

[mtadamek]

Just wondering if I am doing the right thing. We have been closing all of our seacocks after we use the boat. It can go for a month or longer with them closed. Will this cause any type of premature fouling of the heat exchanges, or anything else I might not be thinking of. The reason I am asking is I noticed higher temps on my engines and wondering if my heat exchangers could be fouled. How often should you clean them. Boat has been in the water for about a year.

 

[aquacraig@shaw.ca]

Closing seacocks is probably a good safety practice but should not effect thes cooling system directly (as long as they're re-opened when running!) How hot are you getting on port and stbd? Have you shot a heat sensor around the engine and compared tmps with your gauges? Give us a bit more info.

Craig

 

[REBrueckner]

It's not really necessary to close seacocks but it can't do any harm and will keep them in working order....the risk of forgetting to open one for operation is too great for me to recommend it as a general practice....closing them should NOT do any damage...except maybe to your knees!! I've never heard of a boat sinking because a seacock or hose failed in other the freezing conmditions....and it should not happen in a reasonably well maintained boat.

Common causes of engine over heating: low coolant level; reduced raw water flow due to :worn or broken impeller blades, collapsed intake hose, zinc pieces or impeller pieces blocking raw water flow, barnacles on exterior hull strainer or thru hull; also sea water temps may cause warmer oprating temps...

If this is common to both engines I'd suspect external growth (like barnacles) first, maybe poor quality zincs are blocking water flow....think of common causes first...

comparing engine temps with an infra red gun is the easiest way to get good comparisons...but if both engines are running warm, likely it won't help much...

 

[Genesis]

Closing the seacocks will not cause fouling - but depending on where you are and how close to the edge your cooling system is in general, annual cleaning may be necessary in some form (it was for me here on the Gulf Coast, but we often have raw water in the bays in the mid to upper 80s!)

It's a good practice from a safety perspective - just don't forget to open them before you crank up!

 

[mtadamek]

We are still working the bugs out of this boat. Total refit, my Father rebuilt the engines and gears. We have been working on getting the govenor set up correctly and currently can only reach about 2000 rpm on both engines. Temp climbed to 195-200 on both engines. Temp dropped back to normal as soon as we got back to 1000 rpm. Very rapidly. We have a chetco monitoring system that reports temps on both banks of each engine. All were in that range. Boat has been in the water for almost a year. Heat exhangers were clean and sparkly before they were installed. Have not checked the zincs in the engine yet, very possible they could be fouling the xchangers along with some barnacle growth, slime on the inlets. Pretty sure its not the tstats because they were all running about the same temp. Impellars are good as well as the pumps and wear plates. Fresh water side is clean with correct coolant/anticorrosives. As a safety precaution I always close all water off to the boat. I was just wondering because when I open the toilet valves after being closed for a week or so, and flush the toilet....I have to air out the boat for about 15 minutes. Black stinky nasty water. Just figured that closing all the seacocks might have led to some kind of premature fouling of the heat xchangers. It is probably a combination of fouled xchangers and bottom growth. Will get back to the boat in a couple weeks and do some inspecting.

 

[Walter P]

With all due respect to prior posts, seacocks should be closed when the boat is unattended. Many sinkings at the dock occur when something fails along the line from the seacock to anywhere that's below the water line. Marine insurance companies all recommend it as good practices.

Yes there may be some cooling system maintainance issues to deal with, but it's sure better than arriving at your boat just in time to notice that the boot stripe is about a foot lower than normal......

Incidentally, all seacocks are equally important and can create all of the above concerns. Don't forget also that by working them regularly pretty much assures that they will actually work the way they are supposed to. Too many of us neglect to operate them and when we finally try, they won't turn.

I do suspect that most, but not all of our forum members are very prudent when it comes to maintaining all systems.

Walt

 

[Genesis]

Incidentally, all seacocks are equally important and can create all of the above concerns. Don't forget also that by working them regularly pretty much assures that they will actually work the way they are supposed to. Too many of us neglect to operate them and when we finally try, they won't turn.

By the way, that "when we finally try" is rather frequently when you NEED it to close, RIGHT DAMN NOW. That is NOT the time to discover you have a frozen seacock!

Walter is correct.