vent on bottom of hull

[gmberkley]

Need some help.

I was painting the bottom of the boat yesterday, and saw a vent, not sure what it does, a guess is its a water intake? there is one on each side of the boat, this one in the picture is on the port side.

based on the deterioration, I assume I should change it prior to going into the water, no idea if I should change it, how to change it, or where to get a new one. my big concern if it needs to be replaced is how to do it, I'm sure there is a specific method based on the fact if it's done incorrectly, it will sink the boat.............

any guidance would be greatly appreciated.

Gregg

[Norseman]

Yup, need changing.
Google marine intake strainer, lots of choices.

[gmberkley]

Is there any tricks of the trade to replacing it? I'm thinking I should probably replace both of them, but I don't want to make a mistake, this is not a good location on the boat to practice and learn the hard way, and end up with the boat sitting on the ocean floor from a leak due to my improper installation.

thanks for the reply..........googling now

[Norseman]

Is there any tricks of the trade to replacing it? I'm thinking I should probably replace both of them, but I don't want to make a mistake, this is not a good location on the boat to practice and learn the hard way, and end up with the boat sitting on the ocean floor from a leak due to my improper installation.

thanks for the reply..........googling now

First remove the 4 Phillips head screws and look for more screws under old bottom paint.
Use a box cutter blade to break the bond between the metal and the hull.
It could be 3M 5200 and if so, it will put up a good fight.
If the strainer is badly corroded it may come of in pieces.
Once the strainer is off, clean the hull with a chisel, scrapers, razor blades whatever, then rinse with acetone.
Hopefully the new strainer has the same screw hole pattern: You can read the SS 500, perhaps a model number.
Also you may have to work from the inside if the strainer is one piece with the barb.
Good luck.

[gmberkley]

thanks again, the first of many challenges I guess.

[carolmarie]

If we’re me, I’d hire it out to a good yard. That’s the cooling water inlet to the engine(s), involving a considerable opening in a cored hull. Not anything one should be guessing how to do or even try even with the right directions but with limited skill. Just saying. Don.

[Norseman]

If we’re me, I’d hire it out to a good yard. That’s the cooling water inlet to the engine(s), involving a considerable opening in a cored hull. Not anything one should be guessing how to do or even try even with the right directions but with limited skill. Just saying. Don.

Agree, important job, let a specialist do it, then the work will come with a warranty hopefully.

[gmberkley]

great advise, thanks guys, I can do quite a bit, but when it comes to holes in the bottom of my boat, I'd rather defer to and expert, "a man needs to know his limitations"

thanks again, now the challenge to find the right guy, my boat is in Westerly, RI, where the original owner had kept it, (I bought it a few months ago), small little yard with no workforce. I'm getting it ready for the water, and will be bringing it to Fairhaven, MA when ready............so the challenge starts, find someone down there that will it right.

[Pitou]

There is no magic when it comes to replacing raw water thru hulls, but everyone has their own comfort zone.

Here is a little reading to help gain an understanding of the process whether you choose to tackle this yourself or to just be knowledgeable with your yard performing the work:
https://marinehowto.com/replacing-thru- ... -seacocks/

[WillieC]

Big plus on marinehowto.

Thanks, Kevin.

[gmberkley]

Kevin, thank you very much, a great read..............if I don't do it myself, (hope I'm not forced to), at least I have a very good understanding as to how it should be installed and know what the proper materials should be.

can it be something other than rum??

again, thanks

[Albesaurus]

I’m in the process of doing the same. Mine are not damaged but they were never taken off the hull since the boat was built 19 years ago. I know that because under the strainers there is a shinny green gel coat. Mine are bedded in 42 or 52 hundred ( not sure).

Now i have a question.... should i bed mine back on with 4200? Why does a sea strainer need to be sealed to the hull? Obviously i will bed the screws in sealant but the base of the strainer too??

Here are some photos....

[WillieC]

Albesaurus, your findings are similar to what I found when I did bottom paint on the WillieC, 25 footer. I left the strainer off and arranged my intake to have a straight shot with a plug at the upper end, which I also use for freshwater flushing. If the intake ever jams, just remove the plug and rod it out. Be quick because it might just clear itself in a hurry. Have a couple plugs at hand in case you drop the one into the bilge. Or just close the seacock and go fish.

I have never had to clear the intake as described above and there seems to be more seaweed in the internal strainer, but that is easily dealt with. I do like the straight shot because I get a good look at any barnacle encrustations when hauled.

[Pitou]

I’m in the process of doing the same. Mine are not damaged but they were never taken off the hull since the boat was built 19 years ago. I know that because under the strainers there is a shinny green gel coat. Mine are bedded in 42 or 52 hundred ( not sure).

Now i have a question.... should i bed mine back on with 4200? Why does a sea strainer need to be sealed to the hull? Obviously i will bed the screws in sealant but the base of the strainer too?

The idea of bedding the scoop strainer to the hull is just for another level of adhesion. In the application of your question, I would and have just bedded the screws and run a a thin bead of LifeCaulk around each screw hole in an unbroken bead around the full circumference.

Here is a guide to sealants:

Caulking Guide

Metal to fiberglass: Life Calk (no plastics)
Plastics involved: Life Seal
Permanent or nearly permanent: 5200 or 4200 (no plastics)