Rain down the mast

[Sidney777]

Maybe try the foam in a can & spray down from deck & up from below around mast.

[Lost Horizons]

Originally Posted by Sailmonkey

Think ahead, to future work (additions of lights/sensors or repair of existing). How much fun would that be with a foam plug 10’ up the mast from the bottom?

I was thinking in terms of a furling main mast. For a conventional one it also should not be a problem if there is a cable conduit in place. Anything else?

[Bigjim]

Originally Posted by Lost Horizons

Will you explain why it would be horrible, please?

This stuff is just plain nasty. It's mainly for keeping air out of nooks and crannies but not necessarily water. It's also used for insulation as for iceboxes. It's very sticky and leaves a residue. The foam is not cohesive to itself so if you start whacking at it it comes out in bits and pieces, not as one big chunk. So, it's hard to remove.

There are other substances that are much better for the purpose. Expanding foam has a purpose, but not for this. Also, the voids inside your mast are used frequently for wiring. Using the foam would nix that potential for now and into the future.

Lastly, where would you want to insert this foam? For it to be useful, it would have to added at the top of the mast. Otherwise, the mast could start filling with water. The point of keeping the water out of the bilge is to keep water out altogether not to create a vertical reservoir.

[botanybay]

Originally Posted by Souzag818

Research Spartite. It's designed to replace mast wedges AND seal the mast partners from leaks. Not trying to beat a dead horse, but I've tried mast boot tape, inner tubes, mast boots themselves, butyl tape. Still had leaks. This stuff, actually the McMaster Carr version, solved all my leaking problems

My spartite still seeped a bit under side loads or a serious downpour.

That said I love the stuff, but still have a boot on deck.

[botanybay]

Originally Posted by Lost Horizons

Will you explain why it would be horrible, please?

If you get standing water or a line of moisture held to the metal corrosion sets in from the inside where you cant see it.

[Lost Horizons]

Originally Posted by Bigjim

This stuff is just plain nasty.

Got it, thank you for the explanation, it all makes perfect sense.
I will need to do something to prevent water coming downn the keel stepped mast of my new boat. We discussed it with the dealer and he suggested building up a dam inside the mast at the deck level with a drain opening through the mast wall. They probably had a more reasonable material in mind. It is going to be a furling mast, so only the main channel will be blocked.

[Lost Horizons]

Originally Posted by botanybay

If you get standing water or a line of moisture held to the metal corrosion sets in from the inside where you cant see it.

I think, if properly done, if would not be much different than a deck stepped mast, would it?

[zeehag]

keel stepped aluminum masts need a new boot as often as do wooden masts keel stepped.
sailing gom in a sloop with a leaky boot was not fun. it was cold wet and nasty. add a well made protector boot to your rubber gasket boot and caulk it well, including the track for sail. below decks that track is irrelevant and WET.
my wood mast does well with a boot i made of an oilskin, but more permanent, i believe sailrite product. is beautifully strong and water PROOF. i use caulk to make sure no leaks. is easily done even with aluminum masts. mine present with no leaks even after 5 yrs. awesome material. does not crack in harsh sun.
have fun and good luck. dry is fine. wet is nasty and cold and uncomfortable.

[GordMay]

... Lastly, where would you want to insert this foam? For it to be useful, it would have to added at the top of the mast. Otherwise, the mast could start filling with water. The point of keeping the water out of the bilge is to keep water out altogether not to create a vertical reservoir.

Was answered:

... Another thought is to fill the mast with spray-in foam insulation just above the deck level and then add a weep hole just above the foam, probably in the luff groove. This would have to be done the mast pulled.

However; forming a dam, that far up (+6') from the open foot of the mast, might pose a problem.

[Nicholson58]

Originally Posted by pcmm

If water is getting into the between the mast and the boot, the boot isn't secured to the mast. Its pretty simple. The boot usually has a big hose clamp securing it to the mast. Tighten it and if needed wrap a couple layers of self amalgamating tape over the hose clamp mast interface. Do the same at the bottom of the boot and your done. If you have an internal mast track make sure that its plugged where the boot is or that will let water in too.

I found self amalgamating tape ten inches wide on line. It may tak two strong people to stretch into place but it works. Re coat the outside with 3M 4200 to keep the sun off.

There is also a cast in place product that looks good.

[Caddy Shack]

I second the self amalgamating tape. Cover it with hockey tape to protect from abrasion and keep the sun off. Mine has lasted years and many offshore miles.

[Souzag818]

Originally Posted by botanybay

My spartite still seeped a bit under side loads or a serious downpour.

That said I love the stuff, but still have a boot on deck.

When I poured my "Spartite", I used tape to form a dam at the top of the mast collar. Then I poured it so it's about 1/4" above the top of the collar, and let it flow to the outer edge of the collar. That formed a cap over the collar, and any water that comes down the mast runs over the outer edge. Drip free ever since... I have a boot also to keep UV away, and make it look cleaner, but it's not doing anything else. BTW, I'm in the PNW, where it rains a lot....alot

[Bigjim]

I removed the boot and just discovered I have another issue besides water getting down into the bilge. My mast passes through the cabin top and there is a gap of about 2 inches all the way around with no wedges or other supports.

So, besides replacing the boot, what other types of supports should I consider for that transition?

[Sailmonkey]

Originally Posted by Bigjim

I removed the boot and just discovered I have another issue besides water getting down into the bilge. My mast passes through the cabin top and there is a gap of about 2 inches all the way around with no wedges or other supports.

So, besides replacing the boot, what other types of supports should I consider for that transition?

Spartite or wedges for support of the mast at the partners.

[Bigjim]

Originally Posted by Sailmonkey

Spartite or wedges for support of the mast at the partners.

I've seen people simply shove wood wedges between the mast and cabin top.

I like the Spartite solution from what I have seen of it.