Monday, October 7, 2013

Chainplates, mast boots: making Oceanus water tight

My tarted-up hanging knee with polished and re-installed chainplate.
A couple of weeks ago I pulled the chainplates on Oceanus intending to replace them. I didn't know how old they were and, since they were stainless steel, I worried about crevice corrosion where they went through the deck.

After I cleaned them up, they looked to be in good shape. I polished them and showed them to a boat builder friend and then to a sailboat owner in the marina who owns a metal fabrication business. Both of them declared them to be in good shape and recommended reusing them. "They will last as long as you want to sail the boat," the metal shop owner said. That was good enough for me.

Before I re-installed them, I painted the hanging knees they bolt to and made some other enhancements.
I epoxied on three fragments of a study cast
 by Nora Hall.

In the original interior arrangement, the knees and chain plates were inside some cabinetry and consequently were pretty rough looking. Now the port hanging knee is out in full view above our bunk. I cut away some unnecessary sections of the hanging knee making it look a little more graceful and so it would not interfere with the bunk's occupants. I also thought it would be nice to make it thicker and rounder so it wouldn't hurt so bad when we smacked into it.

To that end, I epoxied a study cast I had from my carving teacher, the late Nora Hall. The cast had already broken in one place and I cut it in another to make it fit the curve better. I filled between the breaks with thickened epoxy. Once it was painted, I liked the way it looked. It provided some visual interest as well as softening the sharp edges for safety. It also reminds me of a great teacher and beloved friend.

All I did on the starboard chainplate was clean and paint it, since it will be inside another cabinet.

While the chainplates were out, I filled the holes where they went through the deck with epoxy to seal the deck core around them. I then cut away most of the epoxy so I could replace the chainplates, but the wood remained sealed and any voids in that area of the deck filled.
The blocks on the knee and the bulkhead
 are for shelves to be added later.

I used bytal tape to seal the chainplates where they came through the deck.

Oceanus leaked (notice the hopeful use of past tense here) where the mast came through the deck. I needed to seal her up before the rains start again. I considered several fixes to this age-old problem, including one system that cost more than $100.

Just in the nick of time, a sailing blog that I read, The Commuter Cruiser, had an article on using a wax toilet seal to waterproof around the mast. Having replaced a few toilets in my time, I thought, This. Could. Work!  (Cue the Young Frankenstein music here.) The wax seal cost about $2 -- way better than my other options.

I ran the wax seal treatment past several of my sailboating buddies. They all thought it should work, but expressed concern that it would melt in hot climates, like the Sea of Cortez, where I hope to be about this time next year. Jan and David of S.V. Winterlude haven't had any problem for the five years the toilet wax seal has kept their boat dry and they cruise in the western Caribbean, where I hear it also gets pretty hot.

One old salt, who sailed to most of the places I want to visit, said he keeps a couple of toilet wax seals in his kit to seal leaks in an emergency. "You just wad it up into a big ball and shove it in the hole," he said. Not a bad idea.
The tools, the old caulking and the blood. When I'm through rebuilding her, Oceanus will have enough of my blood to be a relation.
The worst part of the job was digging out the old caulking around the mast. It was really tough stuff. I think it was some kind of polysulfide caulk. I tried a couple of things to dig it out, but a sharp eighth-inch chisel seemed about the only thing that worked.

I used a flat screwdriver and a half-inch chisel to pull it away from the sides of the mast and the metal ring around the mast. Then I used my Thor hammer to drive the eighth-inch chisel in and pry it out. It was so hard and rubbery that when I got a little bit free I would grab it with my right hand and pull on it while working the chisel under it. I was breaking my cardinal rule about working with knives, chisels and other sharp tools: always keep all body parts behind the sharp edge -- but it was the only thing that was working.

After a short break to get a band aid and stop the bleeding, I carried on until I had the old caulking removed to about an inch deep. I suspect there is at least another inch or more lurking down there, but I think I removed enough to allow the wax to do its job.

The hole for a compression rod.
It was kind of fun to use a putty knife and fill in the void. I made a nice little slope so the water would run off. Then I used some Emergency Tape to cover it so it wouldn't get dirty and also to protect the crew from the sticky goo.

I also used the wax to fill a hole in the casting where the compression rod will go when I reinstall it. The old caulking I pulled out from the hole had signs of water intrusion. I think that was a major source of the leaks.

I also cleaned out old caulking from the screw heads that hold the aluminium casting in place and used Liquid Boatlife Caulk to seal them. I used the same stuff around the edge of the casting, but I think it was a little too thin. I may have to redo that part of the job.
Bol-Wax; don't fail me.
I'll let you know how it works. I have a feeling I won't have to wait long before it gets a good test.