DESCALING YOUR ENGINE

The process of running a suitable (and safe) de-scaling product through

your engine is relatively simple:

1. Remove all zinc anodes from inside the engine. These are typically inside the heat exchanger but there may be others. When you remove the anode, replace the plug to prevent water leaking out the hole. 2. Block the saltwater intake through the hull by closing a stop cock. 3. Connect a circulating pump that can feed water into the engine’s saltwater circuit via the engine intake side. In my case the main intake hose had a smaller connection that the washdown pump was connected to. I simply plugged into this. At worst you may need to disconnect the main inlet hose and plumb into that.

4. Undo the saltwater outlet hose (which may feed into the exhaust, or through its own through-hull fitting above the waterline), and feed this into a large bucket or similar container.

5. The circulating pump should be set to suck water from that bucket and pump it into the inlet hose.

6. First fill the bucket with freshwater and flush the system. Repeat to make sure you have eliminated all the saltwater. Note you may need to start the engine if your saltwater pump is part of this circuit.

7. Then replace the freshwater with the descaling solution, and leave circulating for two to four hours, according to the manufacturer’s recommendations. I prefer not to leave my engine running without cooling water running into the exhaust, so I started and ran it for 30 seconds once every five minutes. This refreshes the de-scaler solution that is sitting in the heat exchangers and pipes.

8. Once the process is complete, remove the descaler solution and flush

the system again with freshwater.

9. Remove the extra plumbing, replace the anodes with a fresh set, and

re-open the stopcocks.

10. Job done. Your engine should now run cooler and more efficiently.