I continually pickup eel grass which frequently blocks/limits raw water intake and caauses overheating. Any ideas on how to block entry at the intake?
RAW WATER INTAKE
- Thread starter Carpe Diem12966
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There's a fitting we used to call a "clamshell"
made of bronze, sort of a flat oval with slots cut out of most of the flat part. A flange around the base holds four small screws. It goes over the raw water intake. I have installed them on lots of boats that I've owned. Maybe a Wilcox Crittendon item?
made of bronze, sort of a flat oval with slots cut out of most of the flat part. A flange around the base holds four small screws. It goes over the raw water intake. I have installed them on lots of boats that I've owned. Maybe a Wilcox Crittendon item?
You should fit a strainer.
A clamshell should be your first line of defense but in addition you should fit a strainer in the intake hose. It will be easier to clean a strainer than the whole raw water cooling system. Last time our engine sucked weeds we had them up all the way into the thermostat.
A clamshell should be your first line of defense but in addition you should fit a strainer in the intake hose. It will be easier to clean a strainer than the whole raw water cooling system. Last time our engine sucked weeds we had them up all the way into the thermostat.
Strainer -Yes!
Any weed within twenty-five feet of my H28 is immediately attracted to my fresh water intake. Fortunately, a strainer is installed in the fresh water line to the motor so the problem is kept from the engine itself. I have learned to recognize the change in the sound of the exhaust when the fresh water intake is blocked. At that point it is a matter of: stop the engine, shut off the thru-hull, clean the filter, open the thru-hull and if no water flows remove the hose between the filter and thru-hull, using the #14 solid copper wire kept by the thru-hull remove any weed in the hose and in the thru-hull itself, and finally open the thru-hull. My friends have suggested the "clamshell". I have resisted installing the "clamshell". I feel that with it installed weed could clog the clamshell itself as well as making it difficult to clean out the thru-hull if it became clogged along with the clogged clamshell. I would rather not have to go diving on the clamshell to clear it. As part of spring fitting out (in about three weeks) I will also install an engine temperature gauge with readout in the cockpit.
Any weed within twenty-five feet of my H28 is immediately attracted to my fresh water intake. Fortunately, a strainer is installed in the fresh water line to the motor so the problem is kept from the engine itself. I have learned to recognize the change in the sound of the exhaust when the fresh water intake is blocked. At that point it is a matter of: stop the engine, shut off the thru-hull, clean the filter, open the thru-hull and if no water flows remove the hose between the filter and thru-hull, using the #14 solid copper wire kept by the thru-hull remove any weed in the hose and in the thru-hull itself, and finally open the thru-hull. My friends have suggested the "clamshell". I have resisted installing the "clamshell". I feel that with it installed weed could clog the clamshell itself as well as making it difficult to clean out the thru-hull if it became clogged along with the clogged clamshell. I would rather not have to go diving on the clamshell to clear it. As part of spring fitting out (in about three weeks) I will also install an engine temperature gauge with readout in the cockpit.
Happenned to me, too!
In 2002, I took the boat to Maine for the summer. During that time, I clogged up 5 times while cruising there. There is a lot of seaweed debris in Maine, with all the currents & stuff. The following summer, I clogged up while charging batterries. Only this time it was a jellyfish. That was the last straw! On haulout, I bought a clamshell-integrated thru-hull and have been lucky if a single blade of grass has made it in during the last 3 seasons.
In 2002, I took the boat to Maine for the summer. During that time, I clogged up 5 times while cruising there. There is a lot of seaweed debris in Maine, with all the currents & stuff. The following summer, I clogged up while charging batterries. Only this time it was a jellyfish. That was the last straw! On haulout, I bought a clamshell-integrated thru-hull and have been lucky if a single blade of grass has made it in during the last 3 seasons.
I replaced my clamshell-integrated thru-hull
with a standard thru-hull and one of these hinged external strainers. The problem with the integrated unit is that you can't get inside the thru-hull to clean out any barnacles that grow in there. I just didn't like it. I had it on my A/C intake and it did keep the weeds out, but it was the cleaning issue that caused me to replace it.
with a standard thru-hull and one of these hinged external strainers. The problem with the integrated unit is that you can't get inside the thru-hull to clean out any barnacles that grow in there. I just didn't like it. I had it on my A/C intake and it did keep the weeds out, but it was the cleaning issue that caused me to replace it.
I installed mine about 19 years ago.
No problem since. I bought a basket-style that looks like the one in Rich's picture but it's held over the through-hull with 3 screws. No attached through-hull = cheap. I also installed one over the watermaker inlet. Perfect. Why aren't they standard equipment. The Groco strainer is loooong gone. Not needed.
No problem since. I bought a basket-style that looks like the one in Rich's picture but it's held over the through-hull with 3 screws. No attached through-hull = cheap. I also installed one over the watermaker inlet. Perfect. Why aren't they standard equipment. The Groco strainer is loooong gone. Not needed.
me too!
2 years ago, after a really bad clog, I decided enough was enough! I added an external slotted cover (small screws, no hull penetration) over the engine and AC pickups, and added a diverter valve so the engine can draw from either inlet-not a clog since!
2 years ago, after a really bad clog, I decided enough was enough! I added an external slotted cover (small screws, no hull penetration) over the engine and AC pickups, and added a diverter valve so the engine can draw from either inlet-not a clog since!
One more thing
I agree with the advice about installing a clamshell screen over the water intake. My additional advice is to install it with the slots facing aft. I have used this strategy on two boats I have owned over the past 15 years and almost never pick-up any eel grass over the whole season. We sail in the Barnegat Bay region of New Jersey and there is lots and lots of grass.
I agree with the advice about installing a clamshell screen over the water intake. My additional advice is to install it with the slots facing aft. I have used this strategy on two boats I have owned over the past 15 years and almost never pick-up any eel grass over the whole season. We sail in the Barnegat Bay region of New Jersey and there is lots and lots of grass.
Slots Back!
I agree that the slots should be turned aft. This has worked for me. Before I started the project, I walked around the boatyard in winter time to check this out. Boats had them going either way. Most forward-oriented were on AC intake, but not the raw water intake. Many had the round, perforated disk on the AC units, also. I had even ran the question as a post on this forum (check the archives) and didn't really get a firm answer. Even the boat yard couldn't give me a firm answer. But the majority of the boats had the raw water intakes aft-oriented. Made sense, so I did it that way. Works fine.
I agree that the slots should be turned aft. This has worked for me. Before I started the project, I walked around the boatyard in winter time to check this out. Boats had them going either way. Most forward-oriented were on AC intake, but not the raw water intake. Many had the round, perforated disk on the AC units, also. I had even ran the question as a post on this forum (check the archives) and didn't really get a firm answer. Even the boat yard couldn't give me a firm answer. But the majority of the boats had the raw water intakes aft-oriented. Made sense, so I did it that way. Works fine.
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