Clogged Sea Strainer

[sailorboy1]

So after 5 years of sailing I finally clogged my engine sea strainer for the first time the other day.

But I caught it WAY before the engine overheated and the engine didn't even get to full temp before I shut it down and went and checked it (and that baby was packed up!).

My first clue was when I started the engine and it seemed louder than normal. My exhaust discharge is down at the waterline and you really can not see the water flow from it, but it did have some water coming out. After a short warm up I increased the rpms intending to motor at about 5 knots, the engine then sounded pretty much normal. But I noticed that it just seemed I had more exhaust smoke than normal and thought maybe that was another clue. So shut it down and went and found the strainer packed.

So for those with wet exhaust, if you experience:
1- louder engine noise on start-up
2 -more exhaust than normal

It would be wise to check the strainer BEFORE you get the high temperature alarm etc and overheat.

PS - I'm sure than all you OLD salts knew this but I had never read or been told to look out for these clues to a seawater strainer being clogged

[David M]

Good advice Don!

[svHyLyte]

Originally Posted by Don Lucas

So after 5 years of sailing I finally clogged my engine sea strainer for the first time the other day.

But I caught it WAY before the engine overheated and the engine didn't even get to full temp before I shut it down and went and checked it (and that baby was packed up!).

My first clue was when I started the engine and it seemed louder than normal. My exhaust discharge is down at the waterline and you really can not see the water flow from it, but it did have some water coming out. After a short warm up I increased the rpms intending to motor at about 5 knots, the engine then sounded pretty much normal. But I noticed that it just seemed I had more exhaust smoke than normal and thought maybe that was another clue. So shut it down and went and found the strainer packed.

So for those with wet exhaust, if you experience:
1- louder engine noise on start-up
2 -more exhaust than normal

It would be wise to check the strainer BEFORE you get the high temperature alarm etc and overheat.

PS - I'm sure than all you OLD salts knew this but I had never read or been told to look out for these clues to a seawater strainer being clogged

And the filter was clogged with?

[Ex-Calif]

Good Catch Don.

Proper (and almost immediate) flow from the exhaust is the second check after engine start. The first, of course, being oil pressure.

A friend started having slow flow. That is it took up to 45 seconds for water to flow. He found the exhaust muff had a small leak, water was draining out of it into the bilge and getting pumped out so he had little clue of the leak. The delay was the muff having to fill before it pumped out.

[sailorboy1]

Originally Posted by svHyLyte

And the filter was clogged with?

weeds and grass, had been at anchor the day before and had noted that there was a lot weed floating around, plus I had gone though quite a few floating grass patches


I had planned to check the strainer earlier when at anchor, but got distracted by something (like a beer probably)

[svHyLyte]

Originally Posted by Don Lucas

weeds and grass, had been at anchor the day before and had noted that there was a lot weed floating around, plus I had gone though quite a few floating grass patches


I had planned to check the strainer earlier when at anchor, but got distracted by something (like a beer probably)

Do you not have an intake strainer on your thru-hull as well as the in-line strainer?

[mbianka]

Don:

This happened to me a couple of times in the old diesel days especially when cruising the Erie Canal on my way up to Canada. Especially after severe thunderstorms washed lot's of reeds (and trees) into the canal. Happily, with electric propulsion this is no longer a concern for me.

[svHyLyte]

Originally Posted by mbianka

Don:

This happened to me a couple of times in the old diesel days especially when cruising the Erie Canal on my way up to Canada. Especially after severe thunderstorms washed lot's of reeds (and trees) into the canal. Happily, with electric propulsion this is no longer a concern for me.

Mike--What's the source of power for the electric drive?

[Maine Sail]

Don,

I check/clean my strainer weekly.... Wow, 5 years!!!

Here in the North East we have an abundance of eel grass beds and literally hundreds of thousands of lobster pots to help rip it from the bottom. We also have 3000 miles of coast line just in Maine with 10+ foot tides. On a spring tide it reaches up onto the shore and drags all the shore weed back into the ocean along with all the eel grass. Before firing up a motor or genset in an anchorage I do a visual inspection of the floating weeds. If it is thick I will opt to not run the motor sitting still.

This summer has been especially bad for weeds and eel grass. It has also been bad for "slime" growth on the strainer screen when not cleaned often enough.

I use a large Perko 0493 type bronze strainer. The strainer has a ball valve to drain it below the top cap to limit salt water spillage during cleanings. It takes me all of about 1.5 minutes to close the seacock, drain off strainer, clean basket, close it back up and open the seacock...

It is rare that I don't find some eel grass in it even with weekly cleanings.....

[jackdale]

I am with Maine Sail - the sea strainer is checked weekly - at least.

On engine start up, we always check for water coming out of the exhaust.

Both of these are standard in the courses that we teach.

[mbianka]

Originally Posted by svHyLyte

Mike--What's the source of power for the electric drive?

A 10kw AGM battery bank, two 48 volt solar panels, 48 volt wind generator and a Honda 2000 generator. And a raw water intake that is now closed though I am considering re purposing it as part washdown system for use in the stern area.

[sailorboy1]

Originally Posted by Maine Sail

Don,

I check/clean my strainer weekly.... Wow, 5 years!!!
....

Just to be clear; I didn't say I had not checked/cleaned the strainer for 5 years. I said that in 5 years that that was the first time it really ever had anything in it.

[Maine Sail]

Originally Posted by Don Lucas

Just to be clear; I didn't say I had not checked/cleaned the strainer for 5 years. I said that in 5 years that that was the first time it really ever had anything in it.

Makes more sense now.

[Katiusha]

Originally Posted by jackdale

I am with Maine Sail - the sea strainer is checked weekly - at least.

On engine start up, we always check for water coming out of the exhaust.

Both of these are standard in the courses that we teach.

We go a bit further than that and do a visual check of the engine at every start-up together with checking the exhaust. Visual check of the engine includes checks that:

- water is lively incoming into the strainer,
- belts are spinning fine,
- no oil or water in the bilge under the engine,
- and generally that everything looks normal.

We've caught quite a few things this way over the years, strainer clogged being the most common. Other items included slacked belt, dried out belt (yes, didn't check the engine before starting), an oil drip and salt water drip (same reason: hose attachments worked themselves loose because of vibration).

We do this check when we leave the anchorage, the dock, when turning on the engine in the middle of the passage (storm, no storm still do it). When motoring a lot, we do this check every few hours as well.

And yes, we do do weekly full engine inspections as well.

[Sandero]

Excellent...

Engine check is mission critical... good practice.