2014 Nov 10, Le Marin, Martinique: Heat Exchanger Woes

After I got to Martinique a week ago I found my expansion tank on the engine full of some sick looking foamy liquid. It tasted slightly salty and there was a bright green liquid in the sump under the engine, so the diagnosis was pretty straightforward. Seawater  leaking into the coolant. This is very bad as it will corrode the inside of the engine and is especially hard on the coolant pump.
The heat exchanger is like the radiator on a car, except it uses seawater instead of air to cool the coolant. After doing that, the seawater is injected into the exhaust gases so it works like a muffler, and cools the hot exhaust, thus preventing fires in a plastic boat. Convenient!

I removed the heat exchanger, ran enough water through it to find the leaky tube. It seemed to be just one tube and was leaking in the middle, so the solution was to plug both ends. The local tech recommended ashore was closed, so I decided to use epoxy to repair it myself.
Acid etch, rinse thoroughly, epoxy with bits of bamboo chopstick to help plug the tube, and heat it up on the stove to speed up the cure.
While working on it I got my wish in the form of heavy rain. My water tanks were nearly empty. Now I have plenty of fresh rainwater to flush and fill the coolant system (not to mention fresh water showers….pinch me!!)  That done, I have to repeat several times to get all the  seawater out of the system. So far, so good.

Other than that, it’s beautiful here. There is a Club Med close by with beautiful “Yoles”. These are traditional sailing fishing boats, that are used now for racing and are very unstable. Make a mistake and more than half the crew is in the water. Most of the crew is moveable ballast.
There was  rain now and then with this beautiful rainbow one day.
St. Anne is gorgeous, and Le Marin is a good place to get work done, and cheese, and bread, and pastries and pates, and etc, etc, etc.

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