J/30 Class Association Forums J/30 Forum The Boat, Sails and Equipment 2GM Heat Exchanger Questions

Vic - during storage to prevent this in the future you need to flush the engine cooling system with clean fresh water, then put in antifreeze with anti-corrosive properties. I usually disconnect the sea strainer and run a 2 gallon bucket of fresh water through the system with a temporary hose (including the strainer), then transfer the hose to the anti-freeze solution until it starts to come out the exhaust. You then shut down the engine and reconnect the hoses.

When you return to the boat after storage you need to remove and clean or replace (if needed) the engine zincs because the antifreeze leaves a film and coats them.