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Showing posts from May, 2009

Port Lights

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The other big project I undertook this spring was to refurbish and reseal the portlights. This turned out to be a really big job. Had I known what a big job it would be I'd have tried to get it done over the winter instead of waiting till two weeks before launch.

Initially I wanted to remove all the aluminum frames, clean them, replace the plexiglass, and reseat them with new sealant. The first frame proved incredibly hard to remove. Even using a putty knife and hammer to cut around the flange, it didn't want to come out, so I gave up on that idea and just removed the plexiglass.

When the boat came out for knotmeter replacement, I found that four of the frames were installed with white butyl and came out very easily. Of course, they'd been leaking like crazy; white butyl isn't a good solution for portlights. They were also extremely gunked up. Two of the frames were very hard to remove and I ended up resorting to brute force with a putty knife and hammer to cut th…

Through with Thru-Hulls

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The epoxy cast turned out great. A two-and-a-quarter inch hole turned into a two-inch hole. Just a few rough edges to sand down.
The new through hull looks good. Lots of LifeSeal (BoatSeal) polyurethane/silicon hybrid caulking around the through hull and up over the threads.
With the transducer in place it's ready for a coat of antifouling. Is it water tight? We'll soon find out.

The transducer is an interesting device; the small paddle wheel on the outside of the transducer spins and interacts with a magnetic sensor on the inside. The sensor is good enough to pick up the frequency of the wheel's rotation through the plastic plug and send it to a instrument panel for conversion into a digital readout. As a bonus there's a temperature reading to test the water on those days when you really feel like going for a swim.

knotmeter retrofit

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This all started by trying to fix the old knotmeter. After some enthusiastic inspection and troubleshooting by my pal, who decided it was broken, the old thru-hull transducer fitting sprung a leak as soon as the boat splashed. I went to the chandlery and checked out my options. There weren't very many.

One was to glass over the whole thing. There were no plugs or other devices for a temporary fix. The best option was to put a brand new transducer in the hole, so I ordered a new Raymarine ST40 Speed by priority post.

Things were looking grand as I drove to the yard with my new knotmeter, but when I tested the thru-hull fitting in the cutout, it rattled around with about 1/8" of space around the whole device. The cutout was too large by about a quarter-inch.

I decided to do an in-situ epoxy cast. My mold consisted of a flat base, pressed up against the outside of the hull, and a 2-inch outer diameter central vacuum PVC tube sitting in the old hole from inside the boat and r…

The Close of the Day

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© 2009 Darren De Ridder

Launch Weekend

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Preparation of the keel joint nearing completion mid-week.

Interprotect 2000 and Sikaflex 291 polyurethane caulking have been applied.



A final layer of Interprotect. I had thought of leaving the polyurethane expsed, since the Interprotect is more brittle, but I painted over the joint after all, to provide a base for the antifouling.

VC-17m antifouling always looks great after it has been freshly applied.

Ready for launch day; fellow Tanzer 22 owners take a break from preparations.


Aura splashes! Cranes and crews had all boats in the water by mid-day.

The first thing a skipper looks for when his yacht splashes in the spring is any water coming into the bilge or around the through-hulls and keel bolts. One of my crew had been working on the knotmeter. Within minutes of launch, water was slowly collecting in the bilge and we were able to trace it to the knotmeter thru-hull fitting. I'm happy that it was discovered immediately rather than springing unexpectedly while nobody was around t…

More Keel Joint

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Progress! Chemical warfare on the hull-keel joint...

Keel Boy™

A gelcoat crack, ground out for patching.

Gelcoat patch and POR-15

Prep was Metal-Ready, containing phosphoric acid and zinc. Residue is zinc phosphate. POR-15 inevitably got on both sides of the joint, but with a topcoat of Interprotect 2000, I expect good adhesion from Sikaflex 291 polyurethane adhesive sealant.