Hull Vents

bdenman · #1 09-07-2009, 06:49 PM

Thanks for all the replies, I guess I'm more confused though than before as most boats with sealed coffins don't have them, I guess most are foamed these days so there is not much bilge to speak of!
I just bought a '79 23' CC OB and am most likely going to paint it over the winter, was just wondering if removeing them was an option, I will probably keep them just for the classic look anyway!

gss036 · #2 09-07-2009, 06:55 PM

I bought my 1989 23 WA new and does not have any type of venting other than the hatches and it came with a 115 gallon below deck tank. I don't think they were required then otherwise they would have been a factory install. My boat came from the "Tampa" factory.

77SceptreOB · #3 09-07-2009, 08:42 PM

Boats are like women......its better to let them vent!!

Bushwacker · #4 09-07-2009, 09:08 PM

Foaming in gas tanks is a BAD idea because the foam will hold water against the aluminum and cause it to corrode thru fairly quickly. This is why none of the original Moesly SeaCrafts ever had the tanks foamed in. Potter didn't foam them in either, at least up thru 72, but it sounds like maybe the later CSY and Tracker boats may have had foamed in tanks.

The early Moesly sterndrives had vent scoops but no bilge blowers, as I don't think USCG required blowers on inboards till about 1967. The idea of the vent scoops is to have them facing forward on one side to force some air in when underway and aft on the other side to suck it out.

BigLew · #5 09-07-2009, 11:13 PM

Close. Forward facing in the bow and stern facing in the stern. Underway way, fresh into the bow and flushes the bilge to the stern. Even at anchor, the bow faces into the wind and in the forward vents and out the stern. The exception is smaller craft with only stern vents, then it is one faces in each direction.

RS · #6 09-08-2009, 10:28 AM

Quote:

This is why none of the original Moesly SeaCrafts ever had the tanks foamed in. Potter didn't foam them in either, at least up thru 72, but it sounds like maybe the later CSY and Tracker boats may have had foamed in tanks.

To add tothe knowledge base - I know that 1978 and 1979s had foamed in tanks. Mine only lasted 28 years so that is not too short, but the failure did happen due to foam. The new tank is not foamed in.

77SceptreOB · #7 09-09-2009, 12:30 AM

Quote:

To add tothe knowledge base - I know that 1978 and 1979s had foamed in tanks. Mine only lasted 28 years so that is not too short, but the failure did happen due to foam. The new tank is not foamed in.

My 1977 definately has a foamed in gas tank.....soon to be pulled out and replaced. Mine lasted 32 years!

77SceptreOB · #8 09-12-2009, 11:13 AM

Pulled my fuel tank yesterday. It was corroded all the way thru and leaking gas - YUCK. See attached picture. Just like everyone said, it was where the foam was in contact with the tank. Foam is coming out before the new tank is going in.

Jim

gss036 · #9 09-12-2009, 01:29 PM

The tank on my 1989 also had a leak, but was in the back and there was no foam in that area. Just powdered corrosion. It was a very slow seep until I had it out where I could see, put water in it and scrapped off the corrosion and the seep went from that to a pee hole. We did re foam the new tank,but put 1/2" poly strips under the tank to allow water to run out if any gets in. Then put mounting strips bottom front and rear instead of the side. My side mounting strips were loose, the screws had been worn out of the glassed stringers. The under deck platform was completely dry.

MARLINT220 · #10 09-08-2009, 11:52 PM

Bushwacker, I recently changed out my fuel tank on my CSY 18' and was really pleased to find that the coffin box was not full of foam when I opened it up. I got 23 years out of the original.