Sealing a Mast Leak

I've found over the last 2-3 years that, after winter, I've had water in my mast. On a hot day, I can hear air hissing out of the "through pin" at the mast rotator/lower diamond wire anchor point, and when I step the mast I get a slow, steady bead of water running out of this location. I've only ever noticed this after the mast sits on the trailer all winter, so if water is getting in during summer rain storms, it must only be a minimal amount. It seems to take a day or more to drain what can't be more than a cup or two of water. I've never noticed water leaking out of the head of the mast (which is usually the low point when stored on the trailer), nor out of the mast base.

I understand that there is a "foam plug" that separates the bottom ~1' of the mast from the upper ~26', so it would appear that there's a very slight path between the rotator pin and the upper mast. I believe there's also a sleeve that goes through the mast, but I'm not sure... My mast is from 79, so I don't think it has the "compression" plates on the side of the mast, and may not be sleeved. No comp tip, clear anodized aluminum. I trailer my boat and keep the mast down most of the time. Obviously this leak isn't going to affect me in a capsize unless there's water already in the mast, but it does bother me that I have to worry about it. Anyone else ever have this issue? Any suggestions for sealing it, without drilling out the mast base?

_________________
Mike

'79 H18 standard 'Rocketman II' sail #14921 RIP
'78 H18 (unnamed) sail #14921
'08 H16 sail #114312
'97 H21SC sail #238

On one of my 16's I had a strange situation with mast leak when capsizing.

The mast alone, off the boat would float and dunk test caused no issues.
Only when the mast was raised and sails rigged did it cause a problem.
It would also retain the water and not leak when de-rigged after lowing the mast.
The mast was heavy and one could feel the water sloshing back and fourth while carrying, but it would not empty.
Required drilling a hole near base so as to empty it for transportation.

Resealed the mast head problem remained.
I then re-rivited and Sikaflexed the mast tang and the problem went away (I think)

So I concluded that the mast tang when under some tension (stays / main / Jib) was causing some movement to allow water in.

_________________
Hobie 14 Turbo (~1979)
Hobie 16 Carumba (1983)
Hobie 16 1990 (storm damaged)
Hobie 16 1996 (my latest)

I have a 78 and seems my situation is near identical to what you describe. Never a lot of water, just always "some". I don't know the condition of my foam plugs. I guess i should take the ends off and check. (Now that i own that heavy duty rivet gun). I have only dumped the boat once in the last ten years and keep it on a trailer, mast down, head down as it seems you do. Here in Wisconsin, i think it trickles in during freeze and thaw of winter/spring months.

I have a 78 and seems my situation is near identical to what you describe. Never a lot of water, just always "some". I don't know the condition of my foam plugs. I guess i should take the ends off and check. (Now that i own that heavy duty rivet gun). I have only dumped the boat once in the last ten years and keep it on a trailer, mast down, head down as it seems you do. Here in Wisconsin, i think it trickles in during freeze and thaw of winter/spring months.