Monthly...what about bi-monthly? Or tri-monthly?
Nope...monthly...here's why:
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| Exchanger zinc after 3 months...it was pitted but intact the last time I looked at it. |
At least no damage was done, a bit of a good clean up due. Chance to change the end-cap gasket as well.
LAZY! LAZY!!!
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| A clean up due, new gasket and some touch up paint. |
Could you explain to the non-nautical what the heat exchanger is for, and why there's a gizmo that needs such frequent changing?
ReplyDeleteOld engines used seawater for cooling, pumping sea (salt) water through the engine passages. This of course leads to extensive corrosion and engine failure. Modern engines still use seawater to cool the engine, but what they do is pump the seawater into a chamber which is filled with meters of copper tubing. Around the copper tubing is fresh water and glycol (coolant), and this hot engine water is cooled by the cold seawater without ever actually mixing. It's a very good system, because the only area that can corrode due to seawater is the heat exchanger (chamber) itself. Some larger vessels pump the fresh water coolant into tubes than run on the outside of the hull, same basic principle. My engine has both a freshwater coolant pump and a raw water (seawater) pump. They mingle without "hooking up".
ReplyDeleteTo mitigate corrosion, which is simply electrolysis (an electrical degradation), one must use a sacrificial anode, made of zinc (called commonly a "zinc"). These break down instead of the surrounding metal. I have a much larger one on my propeller shaft. Wooden boats have them all over the place to protect the screws that hold the planks to the ribs.
John