|
Electrolysis cannot occur on an isolated piece of metal in salt water. It is all at the same voltage but if it is isolated no current can flow so there is no electrolysis. When it is connected to another piece of metal, ESPECIALLY if the other piece is a different metal, you just created a shorted battery and electrolysis will start. By following the wrong advise and bonding everything in the boat you are creating batteries where it is unnecessary and making electrolysis problems worse.
Only bond underwater items that are showing symptoms of electrolysis. Once you bond it unnecessarily you have CREATED the circuit rather than DISCONNECTING it. You are now stuck with providing Zincs since you have removed the first line of protection.
Although some through hulls appear to be isolated due to sitting in fiberglass and using non-metallic tubing, they quite often are not and WILL need bonding. For example the raw water cooling inlet for an inboard engine is in fact connected to the engine block by the salt water in the tubing and may need bonding so the current flows though copper rather than the water and in/out of the through hull.
|