I learned a little lesson in bonding yesterday. Yeah, OK, I'll also post a pretty pic of something I've photographed in the last week, but first I want to post a show-and-tell photo.

See the white plumber's tape? That's the part of the pipe that was outside of the fitting on the sea water strainer for my reverse cycle A/C units. So where are the threads that were inside the female part of the strainer? Gone. Gone, as in electrolysised away.

Like many, I'm pretty fuzzy on bonding. Some articles I've read insist that all metals in contact with seawater must be bonded by being connected to the boat's ground, and others say nothing should be bonded. Which is it?

In this case, the strainer body was bonded. But look at the pipe fitting, which is about six months old. It has plumber's tape on the threads, which effectively isolated it from the bonding system. The result was electrolysis and a severe thinning of the inside of the pipe. If I wasn't in the engine room showing my boat to a couple and if I didn't hear the drips, I could have quickly had a 3/4" hole in my boat.

I replaced the fitting with a new one, and I also used plumber's tape. I need to figure out how to bond this little piece of pipe. Hmmm.... maybe I should just remove the tape?