I never said to put zincs on bronze through-hulls. I have never seen zincs on through-hulls. My through-hulls are electrically insulated from iron and since 1981 they have shown no effects of corrosion.
Zincs are mostly to protect ferrous based metals such as steel and stainless against the natural galvanic attack from copper based metals. That's why they are put on shafts, to protect the iron in the stainless. When copper was first used to protect wooden ships from worms it was discovered that the iron rudder hinges were rapidly disintegrating. Thinning of the copper at the bows was at first thought to be caused by water rubbing away the copper, but eventually realized it was from pressure cell galvanic corrosion where there were small impurities in the copper set up a galvanic corrosion situation accelerated by the pressure of the water at the bows. Props that are damaged by electrical based corrosion is usually from the boat's electrical system and zincs can protect from that to a point but are rapidly used up. For battery terminals I melted a jar of Vaseline in a pan of water, removed a couple of tablespoons, and stirred in baking soda to refill the jar. I have noticed that on my boat and my cars the most corroded pole has always been the positive one. Grounds get into trouble when dissimilar metals get involved such as a crimped ring terminal (I never use fork terminals, they trade away safety for convenience) and ferrous metal. Using the soda laced Vaseline helps a lot. Norm S/V Bandersnatch Lying Gloucester MA > As Norm said, put zincs on, to protect your prop and bronze > through-hulls. Some boats are set up to accept a plate zinc on the > hull as well as a doughnut or collar zinc on the prop shaft. If you > don't connect to shore power you eliminate or substantially reduce > the galvanic corrosion problem. > > I don't know if this is unique to salt-water environments, but it > never hurts to put some anti-corrosion stuff (Corrosion X or > Corrosion Block (which also comes in a grease form) or Lanokote or > even just petroleum jelly) on battery terminals and electrical > connections, especially ground connections. Seems that ground > connections get funky faster than others, at least on my boat. Don't > know why. But when something electrical doesn't work or works > erratically, cleaning up the ground connection seems to solve the > problem about 75% of the time. > > There are a few thoughts; others will no doubt have a multitude of > further suggestions and opinions. HTH, > > Phil > s/v Cynosure > Bahia de Caraquez _______________________________________________ Liveaboard mailing list [email protected] To adjust your membership settings over the web http://liveaboardonline.com/mailman/listinfo/liveaboard To subscribe send an email to [email protected] To unsubscribe send an email to [email protected] The archives are at http://www.liveaboardonline.com/pipermail/liveaboard/ To search the archives http://www.mail-archive.com/[email protected] The Mailman Users Guide can be found here http://www.gnu.org/software/mailman/mailman-member/index.html
