Water in the mast....leaks inside

[pwilletts]

Water accumulates inside my mast and leaks slowly into the sole where the mast meets the keel step....sealing around the bottom of the mast is one solution..there is a seal there but it seems to leak....I would prefer to stop the water at deck level... has anyone tried expandable foam inside the mast....??

[Glenn.Brooks]

Mast leaks are always a nuisance. The best solution is refit the mast boot and seal all the holes up the mast to keep water out in the first place. I have not tried foam inside a mast, but have used it to insulate fish holds in fishing boats. Some types of foam act like sponges and absorb and hold lots of water. I doubt this would work for you. Better to seal up any holes in the mast and refit your deck seal. Some very effective deck seals can be made by calling the gap between the mast and the deck opening, then covering the gap with a mast boot (piece of rubber or sunbrella (aka canvas) turned up the mast) bedded in Dolphinite and affixed to the deck, then painted several times to make it impervious to water penetration. Of course there are more modern synthetic materials to choose from as well. Choose something you like, that matches the era of your boat. It will work out for you, Iam sure.

[Paul Elliott]

But internal halyard mast openings just can't be sealed. I've read about people pouring an epoxy "dam" in the mast, just above the mast boot and drilling drain holes there. I would want to make sure that all the water can drain out, rather than being some trapped inside the mast.

[er9]

Originally Posted by pwilletts

Water accumulates inside my mast and leaks slowly into the sole where the mast meets the keel step....sealing around the bottom of the mast is one solution..there is a seal there but it seems to leak....I would prefer to stop the water at deck level... has anyone tried expandable foam inside the mast....??

that does not sound like a very smart idea with the foam. if there is water in your mast you absolutely want it to leak out into the bilge. you will have an extremely difficult time sealing a mast 100% as all it takes is rain entering the top of the mast. i get 1.5 gallons of rainwater in my bilge just from a couple days of heavy rain. if you stop it from exiting the mast at the bottom it will accumulate inside anyways, corrode and rot your mast from the inside out. my advice is to enlarge the hole at the bottom and let the bilge pump do its job.

[UNCIVILIZED]

Guys the core of the idea is to keep the water from entering the boat via the mast, period. In theory anyway. And to do so, in addition to having a 100% watertight mast boot seal system, you don't want the water which inevitably enters a mast, to be able to get into the cabin. Specifically the bilges.


In theory, one does this by creating a foam dam inside of the spar, sometimes atop an inflated balloon. Just above the bottom of a couple of the halyard exit plates. And by creating a positive meniscus of foam there, which you then seal up so that it cannot absorb moisture, via waterproof paint, & or epoxy, etc.


The reason for the location being that any water entering the spar via the sheaves, or other small access points, will (theoretically) all drain out where the halyards exit the mast a little ways above deck level.


As to it's long term hazards to the integrity of the mast tube. Odds are you won't get a spar maker to give you a guarantee on this in writing, but it's worth a try


And if you haven't guessed, there are more than a few threads on this exact topic, here on CF. One as ancient as 3 days old. Do a search. One tends to learn s**t that way.

[thinwater]

In my experience, expanding foam against metal is a great way to start corrosion. Internal corrosion at deck level is a nightmare scenario.

I think there is a very good reason this is not done. Drop the idea and figure out a way to reduce leakage and deal with it a the mast step.

[Patrigo]

Try:

http://www.seabreeze.com.au/forums/S...-Collar?page=1

from Jan 11 2016. A 20th century solution to a problem caused by boat builders using a 300/,400?,500? year old method to fit a keel stepped mast. Get with it and it cannot leak.

[Benz]

The only sure-fire way to keep water getting in is to have a mast with no access to the water. That means no openings in it--external halyards, blocks aloft rather than masthead sheave box, etc. Wires? I avoid wires in masts (mine has none), but well-sealed ones, if at all.
If internal halyards and sheave boxes are a must for you, then the problem of water will be perpetual, or the worry that a dam is trapping water and causing corrosion.
Another solution is to deck-step, if that can be engineered, but converting from keel-stepped is not trivial.

[thinwater]

Originally Posted by Patrigo

Try:

www.seabreeze.com.au/forums/Sailing/General/Deck-Leaks-Mast-Deck-Collar?page=1

from Jan 11 2016. A 20th century solution to a problem caused by boat builders using a 300/,400?,500? year old method to fit a keel stepped mast. Get with it and it cannot leak.

In other words, weaken a heat-treated spar by welding on it. Basically, it becomes a deck-stepped mast with an integral compression tube.

Just curious, are any boats built this way?

[Patrigo]

Some photos, I hope.

[UNCIVILIZED]

Originally Posted by thinwater

In my experience, expanding foam against metal is a great way to start corrosion. Internal corrosion at deck level is a nightmare scenario.

I think there is a very good reason this is not done. Drop the idea and figure out a way to reduce leakage and deal with it a the mast step.

AMEN to this. I think the only reason that water coming in this way is an "issue" has to do with "modern" boats which have no bilges, & are round bottomed. So that even a tea cup's worth of water inside creeps all the way up the hull side as a boat heels, soaking everything in it's path. Bilge sumps ain't popular anymore. So "sealing" the mast is the "solution".

[suenodelmar]

I had this problem with a deck-stepped mast on my Downeaster 38. Rain water would enter the mast through the myriad of holes. There was no practical way to stop it from entering. The water would then seep through the wiring exit holes, pass through the mast foot and the deck, and damage the compression post and bulkhead. The solution was to drill two half-inch holes on opposite sides of the mast, located about two inches above deck level. I vacuumed out the accumulated crud with an angled snout attached to a shop-vac.. Then, I injected self-leveling caulk available at Recreational Vehicle supply stores. Ordinary caulk like 3M 5200 or Sikaflex is too viscous and will not flow to fill the gaps. The self-leveling caulk must be injected in several layers because if a single, deep layer is injected, it may take several weeks to completely dry. I was able to fill the base of the mast up to the level of the bottom of the holes with three injections allowing about two weeks of drying time for each layer. Thinner layers may have dried faster. Now, when water enters the mast, it flows harmlessly out the holes onto the top of the deck. The interior of the boat is FINALLY dry!

[Patrigo]

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[Patrigo]

http://PenLOP4.JPG

[Dave22q]

Originally Posted by pwilletts

Water accumulates inside my mast and leaks slowly into the sole where the mast meets the keel step....sealing around the bottom of the mast is one solution..there is a seal there but it seems to leak....I would prefer to stop the water at deck level... has anyone tried expandable foam inside the mast....??

A closed cell foam might work but no way to watch for deterioration over time. Better solution would use a dense non corrosive liquid that is heavier than water to fill the mast base up to your above deck drain holes. Some kind of tar or asphalt might work well. You might need to patch any below deck holes before starting. Anything that cracks as it dries would be bad but leaving an inch or two for water to accumulate on top of your sealant should prevent drying.
If you go this way realize it may be irreversible, not much chance of removing whatever you insert. Good luck.