Astraea has a Westerbeke 44 Engine. In the heat exchanger there is a pencil zinc exposed to the saltwater cooling loop. The pencil zinc corrodes away sacrificially instead of the engine. Monthly I check the zinc to see how much has corroded. In December I changed the zinc out with a new one. I searched online for the zincs and found them at first for $6 each. After further searching on Amazon I found them for $2.50 each plus $10 shipping. Since they’re a common wear item I bought 10 to bring the total price each to $3.65.
The part information is here for anyone else who may be looking for the best deal on these zincs. Westerbeke / Universal Part number 011885. They’re shipped and sold by RotoMetals, a 5 star seller from San Francisco. Here’s the link to the best priced zincs.