Rainwater in Bilge

[Alma]

My ALMA is stored ashore and I am getting a little water in the bilge from rainwater.

It is in the top bilge around the maststep and rarely is enough to reach the bottom sump bilge.

It is not coming from the anchor locker. I don't see evidence of water coming in through any ports or hatches.

I don't have water coming in through the mast hole in the deck.

We've had a lot of rain in NJ lately and I'm wondering if it is all coming through the sheave box at the top of the mast.

Does anyone see a source of rainwater I'm missing?

[Dolce_Vita]

I used to see the same thing.  I'm sure it came through the sheave box at the masthead. 

There are two large openings in it to allow for conversion to internal halyards. Since I elected to stay with external halyards during my mast rebuild last year, I elected to close off these openings.  This drastically reduced the amount of rainwater I find in the upper bilge (I've still got a few small leaks in the fwd ports in the v-berth).

[Alma]

I see! I use external halyards so I'll follow your lead. How did you close those holes?

[Dolce_Vita]

Closing them is easy.  Getting to them is the hard part.  They need to be closed from the inside.

In order to remove the masthead, both the forestay and backstay need to be removed.  Also any instrumentation and lights mounted on the masthead fitting.

Then, the masthead itself is held on with ~8 SS self-tapping screws through the mast.  These will be heavily corroded in-place  and may break off.

Unless you're up for a McGuyver'd temporary rig, and superhuman acrobatics aloft, this really means that the mast needs to be down for this modification.  I did it as part of a total mast rebuild, which included getting the masthead fitting (along with the whole mast) sandblasted and repainted with Awlgrip.

Once I had a nice clean surface to work with, I figured anything non-wood would work. Didn't need to be strong, just watertight and rot-proof.  I cut two small rectangles from a scrap piece of plexiglass and secured them in place with Dow Corning 795.  This industrial-strength Silicone has significant adhesion strength, unlike consumer-grade hardware store silicone.

Like I said, a pretty easy fix, once you get to the bottom of the fitting! :-O

[Alma]

Nuts!

I had my mast off to strip the paint and install new maststep last Spring. When I bought the boat 15 years ago I pulled all the Al castings from the extrusions and replaced the self tappers with allen head  cap screws into Heli-Coils in the castings. I had a lot of time then and it payed off. When I needed to inspect the wiring this Spring the sheave box fasteners unscrewed like butter.

Next time I pull the mast I'll follow your lead. I have no desire for internal halyards.

Bare-Naked Al mast lookin' great after one season. No signs of corrosion.

[Dolce_Vita]

... I pulled all the Al castings from the extrusions and replaced the self tappers with allen head  cap screws into Heli-Coils in the castings. ...

Man, what a great idea!  I wish I had thought of it last winter when I had everything apart and sandblasted!

I put TefGel on every single screw in the mast & boom when I reassembled, in the hopes of staving off galvanic corrosion and making them easy to extract in the future.

[Sea Haven]

Alma,

I had my mast off to strip the paint and install new maststep last Spring.

Did you just strip the paint off and leave the aluminum natural? Or is there a finish over it?

I so want to refinish the mast but the budget isn't there to re-anodize or paint it. I prefer the natural aluminum look but can't seem to find a definitive answer for a finish so it won't oxidize over time.

"Sub" Ed

[Alma]

French boats use bare aluminum hulls (above the waterline) all the time. I have only had one season with the mast stripped of it's black paint. It looks fine. I used aircraft stripper (paint remover) on advice of a friend who said it may have anodizing under the paint I shouldn't sand away. I initially had trouble with the remover. I used plastic wrap to keep the stripper wet on the mast yet it wasn't cutting the paint- especially the tough yellow primer under the black.

It turned out it wasn't warm enough weather. When it warmed up the job went easy-ier.

The bright silver aluminum looks so sharp compared to my spotty black painted spar. I had the boom refinished glossy black a number of years ago so I left the boom black. The mast looked like the camouflage on submarine periscopes before!

For fun I painted the spreaders "Tangerine" like my little '69 911S! Easy to see in a roiling sea and so fun.