Furling Mast Water Ingress

KZW

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May 17, 2014
831
Catalina 310 #307 Bluewater Bay, FL
I've owned my boat for three years. In that time I've tracked down and fixed several leaks:
- Replaced a port light
- Rebedded another port light
- New gasket on yet another port light
- Replaced the gasket on a hatch lens
However, one leak has vexed me for some time, with water in the bilge every time it rains. Today, I found the rather obvious culprit. See the picture. The mast is open around the bottom of the screw fitting for the in-mast fuller. Rain water just pours on down inside the mast directly into the bilge.

- Do any of you C-310 owners with in-mast furling have this problem?
-- If so, what did you do about it?
- Am I missing some sort of fitting or gasket?

I'd really like to keep the bilge dry and remove this as an ingress point, especially in the event of a tropical storm or hurricane!

All ideas considered. Thank you in advance.
 

Attachments

Jan 17, 2013
439
Catalina 310 St. Simons Island, GA
It is a deck stepped mast with a compression post so how does the water actually enter the boat?
bob
 

SG

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Feb 11, 2017
1,670
J/Boat J/160 Annapolis
Instrument and lighting wiring, for one. There may be other leaks.
 

KZW

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May 17, 2014
831
Catalina 310 #307 Bluewater Bay, FL
I'm not inclined to drill a hole in the base of the mast without knowing exactly what the base inside the mast looks like.

I'm considering stuffing tissue/paper towel/tape in the holes around the jack screw and shoot in some expanding foam to plug the holes, thus keeping the water out.
 

SG

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Feb 11, 2017
1,670
J/Boat J/160 Annapolis
You can't keep all the water out. You need to find a way to relieve it.

If you foam it in, when you need to get through it, you (or the next guy will regret it.
 
Nov 18, 2013
171
Catalina 310 Campbell River
If you use foam and you later want to add some instrument in the mast or change out, you'll have a mess.
 

KZW

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May 17, 2014
831
Catalina 310 #307 Bluewater Bay, FL
If you use foam and you later want to add some instrument in the mast or change out, you'll have a mess.
I don't think so. The mast wires run down a channel at the front of the mast. The foam won't be in that channel. Further it won't fill the mast, but just fill the holes (see picture in my first post), around the jack screw fitting. It is my hope the foam will only be about 1/2 to 3/4 inch thick and is easily removable. Note: The attached picture isn't my mast but shows the wire channels and the round channel in which the jack screw is mounted.
 

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SG

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Feb 11, 2017
1,670
J/Boat J/160 Annapolis
You will get water down the mast from above from the sheaves at the top of the mast. Mold will grow in the foam.
Eventually you'll get water building-up and while you'll reduce the volume, you'll still not keep it sealed?

If the mast if off, why are you loathe to drill a 1/8" or hole or two in places that will allow the water to reasonably drain and limit the "head" of pressure on the instrument wiring seals?
 

KZW

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May 17, 2014
831
Catalina 310 #307 Bluewater Bay, FL
My mast isn't off. The picture I posted of the mast cross section was from a post on this site from another contributor.

Yes, some water will still find its way in. However, the foam will block the rather large openings which are conducive to a significant amount of water ingress.

Where do you think this water is going to build up? The foam isn't at the bottom of the mast - that is inaccessible. The foam is at the bottom of the in-mast furling screw. I put it in this morning. Look at the picture in my first post. The foam is adjacent to the base of the furling screw plate, filling the two holes that can be seen right and left of the plate. The foam is perhaps 1/2 inch thick, the thickness of the plate. The top of the foam is level with the top of the plate. The foam is easily removed. I will post a picture the next time I go to the boat (I didn't bring my camera this morning). If it holds back the torrent, and needs to be replaced once per year, then it is well worth while. I will report what happens - thunderstorms are predicted for later today and over the next three days.
 

SG

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Feb 11, 2017
1,670
J/Boat J/160 Annapolis
Where does the water that is supposed to stay on top of the foam go?
 

KZW

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May 17, 2014
831
Catalina 310 #307 Bluewater Bay, FL
Realizing that you don't have a C-310 with furling main. look carefully at the picture I posted with the original question. You are looking at the back of the mast, below the boom, at the screw that turns, furling the main inside the mast. This entire area is open. Look at the mast on your boat under the boom and picture a two-foot vertical section of the back of the mast removed, leaving the inner area open to the air.
Again, looking at the picture, you see the screw and its mounting plate. The plate is circular, the mast cross section isn't. So, there are two holes, either side of the plate, which are completely open to the elements, and have a straight shot down the mast, down the compression post, and into the bilge. One Thunderstorm can dump one to two inches of rain. Here in coastal Florida, that can be a daily occurrence in the afternoon during the summer. I don't like 3/4 - 1 inch of water sloshing in the bilge all the time. (Its a personal issue. You may have heard that Florida has a moisture / humidity issue in the summer. Note the nice shade of green on the halyards in the picture. We grow some real stout mold here. God make air conditioning to make Florida livable in the summer. The less water inside the boat, the less water the dehumidifier must deal with). The opening in the mast gathers this rain and the water runs down into the bilge. I injected a small amount of foam, filling the holes on either side of the screw mounting plate. The foam is level with the top of the plate. Any water collected will run out the opening in the mast, down onto the deck. There is a 1/32 inch gap between the rotating screw and the mounting plate. Some water is going to find its way into that area, but it is better than two gaping holes exposed to the elements (poor design by Charleston Spar).
 
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KZW

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May 17, 2014
831
Catalina 310 #307 Bluewater Bay, FL
Success! There was some moderate rain today, perhaps 0.5 inches. The bilge was bone dry after the rain moved off. More rain is forecast each day through Saturday. I will post on how the foam performs in a heavier shower.
In the pictures, the foam is white vs. the aluminum mast. It fills the gap between the fur
Mast Furler.jpeg
Mast Foam.jpeg
Mast Furler.jpeg Mast Foam.jpeg ler base and the mast.
 

KZW

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May 17, 2014
831
Catalina 310 #307 Bluewater Bay, FL
It works, but it isn't a miracle. We had 3/4 inches of rain Wednesday, an almost two inches yesterday in hard, driving rain. The bilge had water in it (below the level that the pump can pump out. I think this water came in from the shelves at the top of the mast, but don't know for certain.
 
Jan 17, 2013
439
Catalina 310 St. Simons Island, GA
Initial results from this are very promising. I used tape to close off the area and after a couple huge rainstorms the bilge was bone dry. So now have used the spray foam although my application was not nearly as neat as the pictures posted here. Have been away from the boat for 10 days since then so will check it out this coming week and see what it looks like!
bob
 

KZW

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May 17, 2014
831
Catalina 310 #307 Bluewater Bay, FL
We've had 15 inches of rain in the last three weeks. I still get water, but nearly as much as before. I did find the foam shrinking in the sun and pulling away from the walls. I may go to a polyurethane foam.
 
Sep 29, 2008
1,928
Catalina 310 #185 Quantico
[QUOTE="... we just add a little simple green and it keeps it clean.[/QUOTE]

Leo, Can you elaborate on this? Do you swirl it around or just let it sit there. My bilge could use a little cleaning but there are a few spots that would be hard to get into.

While I don't have the furling mast after working on a friends 309 there really is no reason you should get water intrusion through the mast unless your penetration points for the wires are improperly sealed. His 309 Selden mast has openings at the bottom where water can easily get out and drain off.
 

KZW

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May 17, 2014
831
Catalina 310 #307 Bluewater Bay, FL
"His 309 Selden mast has openings at the bottom where water can easily get out and drain off."

There are no openings at the bottom of the C-310 Charleston Spar furling mast to let water out. There are several openings above, to let water in!
Some posts have advocated drilling weep holes in the bottom of the mast. I'm loath to do this unless someone posts pictures and provides detail on exactly what they are drilling into. When I mounted a track for the whisker pole on the mast, I got a cross section diagram to ensure I knew what was behind the area I was drilling into.