Water in my mast

EN2

New Member
Took my new (1974) boat out a couple weekends ago. Had a blast and everything worked great. When I got it home and put it in the garage to clean it up, I noticed that the mast had water in it. I read in another thread about a draining mast. Is this an option or do I need to replace the caps. Thankyou for any input. I havent posted any but have gotten lots of info about my boat.
 
Ours would take on water, too, which made it a little harder for lighter kids to right the boat after a capsize.

I took off the upper and lower mast caps by pushing in the litle pins that hold them in place (with a small punch and hammer) and then carefully working/prying them off. Then removed the ancient, dried up/rotted cork plugs at either end. Manually brushed/sanded corrosion out of the ends and sealed some corrosion pinholes w/ epoxy. Cleaned the end caps and placed a small bead of silicone sealant around the lip/corner where the caps seat against the mast ends, and then reinstalled end caps. Pins were replaced with silicone sealant as well.

So far, the mast has remained dry and waterproff since this treatment. Similar procedure for the spars (removed and reinstalled block straps with sealant on the lower spar).

Oh, also drilled and tapped the base cap on mast as a drain hole, then installed a short stainless steel screw with a rubber washer under the head as a plug -- just in case water works it's way back in there some day.
 
Ours would take on water, too, which made it a little harder for lighter kids to right the boat after a capsize.

I took off the upper and lower mast caps by pushing in the litle pins that hold them in place (with a small punch and hammer) and then carefully working/prying them off. Then removed the ancient, dried up/rotted cork plugs at either end. Manually brushed/sanded corrosion out of the ends and sealed some corrosion pinholes w/ epoxy. Cleaned the end caps and placed a small bead of silicone sealant around the lip/corner where the caps seat against the mast ends, and then reinstalled end caps. Pins were replaced with silicone sealant as well.

So far, the mast has remained dry and waterproff since this treatment. Similar procedure for the spars (removed and reinstalled block straps with sealant on the lower spar).

Oh, also drilled and tapped the base cap on mast as a drain hole, then installed a short stainless steel screw with a rubber washer under the head as a plug -- just in case water works it's way back in there some day.


Good tip. Thanks. I'll try that too!
 
Sounds like an easy enough fix. Screw in the bottom should get the water out so I can use it this weekend the repair it proper this week. Thanks for the quick response. Keep you updated.
 
I was going to ask that but looked in the hole for the mast and realized that myself. I'm glad someone posted this so other people know. Took all day for the water to trickle out but worked well.
 
Neat idea. Make sure though that the screw is recessed (doesn't stick out).

Actually, the screw head does stick out, but not an issue since bottom of the mast step hole has a recessed area in the middle. There is a "shoulder" around this recessed area that holds up the base of the mast. If you keep the screw in the middle, it shouldn't touch anything. Maybe not all Sunfish have this center recess in the mast step, though?

If you try to use a countersunk/recessed head screw as a plug, you might have to glue a nut on the inside of the mast cap to hold it. The mast base cap plastic is pretty thin -- doubt there is enough room in the cap base for both a countersink and then some threads to hold the screw plug all by itself. Maybe some sort of rubber plug could be used instead? Couldn't find any suitable ones when I looked, but doesn't mean they're not out there.

I used a pretty big screw (maybe half-inch diameter shank) so my drain hole would be big enough to drain water w/out too much trouble. Will probably leave screw plug out over winter to "air out" the mast interior (although doubt a hole that small will let much air circulate). So far the whole set-up has remained water-tight, though, so may not be a concern.
 
Here is a picture of that "shoulder" in the bottom of the mast hole, as taken from an early '70's model.
 

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... also drilled and tapped the base cap on mast as a drain hole, then installed a short stainless steel screw with a rubber washer under the head as a plug -- just in case water works it's way back in there some day.
In the grand scheme of things, a well sealed mast is the goal. If you detect a broken seal and water has snuck in, draining is just half the job, you still need to dry and reseal, rinse, dry and reseal in the case of salt water.

Without drying, moisture, especially saltwater is going to slowly and steadily corrode away at the mast from the inside out. I've seen 1" holes drilled in the base cap for instant draining..., then later rinsing and drying. Not my favorite approach, but better than trapped moisture.

I used a pretty big screw (maybe half-inch diameter shank) so my drain hole would be big enough to drain water w/out too much trouble. Will probably leave screw plug out over winter to "air out" the mast interior (although doubt a hole that small will let much air circulate). So far the whole set-up has remained water-tight, though, so may not be a concern.
I think you have the right idea and have recognized the drawbacks. Keeping watertight is the real key. Someone sailing saltwater would need to consider how to rinse.

Once you see pinholes develop you have visual evidence corrosion has eaten clean through the metal. Failure is eminent at that point.
 
I agree that resealing is the best bet. Thought being that drain is short term fix. Was the fastest way I thought of to get the water out of the mast without taking the boat out of commission. Had to fix dads power boat this weekend and work on the sail club dock next. Sometimes life gets in the way of sailing.
 
what if you opened the leaking end cap, dried the interior and filled it with that expandible form used to fill gaps when installing new house windows?

Then reinstall the end cap with good caulk.

then if something leaks again, the mast won't fill up.

Mike
 
On second thought, just put a solid plug of expanding foam maybe 6-8 inches down, at both ends.

what if you opened the leaking end cap, dried the interior and filled it with that expandible form used to fill gaps when installing new house windows?

Then reinstall the end cap with good caulk.

then if something leaks again, the mast won't fill up.

Mike
 
spray foam doesn't always fill in all the gaps. I'd hate to put it in my mast then have another leak develope and have to dig all that stuff out if water got traped between the foam plugs. I'm still thinking resealing the caps is the best way to go.
 
here's what I did;

I dried out the cork plugs thoroughly in the sun and coated them with silicon caulking and installed them just inside the caps to act as a backup seal.

I then re caulked the caps, installed drilling new holes at 90degrees from the old and reused the old pins, caulking over them thoroughly.
 

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